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Life-cycle energy analysis of an office building Kernan, Paul Christopher 1996

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LIFE-CYCLE ENERGY ANALYSIS OF AN OFFICE BUILDING by PAUL CHRISTOPHER KERNAN Dipl. Arch., Dublin Institute of Technology, 1983 B. Arch. Sc., Trinity College Dublin, 1983  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ADVANCED STUDIES IN ARCHITECTURE in THE FACULTY OF GRADUATE STUDIES (School of Architecture) We accept this thesis as conforming to the required standard  THE UNIVERSITY OF BRITISH COLUMBIA February 1996  © Paul Christopher Kernan, 1996  In  presenting  degree freely  at  this  the  available  copying  of  department publication  of  in  partial  University  of  British  for  this or  thesis  reference  thesis by  this  for  his thesis  and  or for  her  The University of British Columbia Vancouver, Canada  DE-6  (2/88)  study.  I further  purposes  gain  the  shall  requirements  agree  that  agree  may  representatives.  financial  of  of  Columbia, I  scholarly  permission.  Department  fulfilment  It not  be is be  that  the  for  an  Library shall  permission for  granted  by  understood allowed  advanced  the that  without  make  it  extensive  head  of  copying my  my or  written  II  ABSTRACT The thesis investigates the life-cycle energy requirements of a generic office building. Energy use is seen as a key determinant in many of the most serious environmental pressures threatening human existence. Reducing current high levels of fossil fuel consumption is imperative as a first step to addressing and solving these problems. Energy use in the construction industry, to both operate and construct buildings, represents a significant portion of total global energy consumption and reductions in this component of total energy use will be essential. The thesis examines the potential for energy reduction in office buildings by analyzing the energy consumption characteristics of a generic 5 storey office building located in the Lower Mainland of British Columbia. Analysis is carried out on the basis of life-cycle energy consumption The individual components of office building energy use, operating energy, embodied energy and demolition  energy,  are calculated.  In  order  to  investigate  total  life-cycle  energy  requirements three alternative future scenarios are proposed for the building. The direct and indirect impacts of future changes in key energy related variable is investigated. The relationships  between  the  different types  of energy  are examined  and their  relative  contributions to total life-cycle energy is analyzed. Various strategies to improve energy efficiency are examined and the total potential energy reduction is calculated. Life-cycle energy of the study building over a 100 year life span is calculated at between 77.7 and 80.2 G J / m . Operating energy represents the largest portion of building life-cycle energy, 2  accounting for between 80 and 8 7 % of the total. It is also the energy component that offers the greatest potential for achieving reductions, with potential saving of up to 60%. Embodied  Ill  energy accounts for between 12 and 1 9 % of total life-cycle energy. The maximum achievable reduction in embodied energy is approximately 40%. Demolition energy, at less than 1 %, is a relatively insignificant component of building life-cycle energy. The potential reduction in overall life-cycle energy is between 57.8 and 59.2 percent.  iv  T A B L E OF CONTENTS  Abstract  ii  Table of Contents  iv  List of Tables  x  List of Figures  xii  Chapter 1  INTRODUCTION  1.1 INTRODUCTION  1  1.1.1 Fossil Fuels and Global Warming  1  1.1.2 C h a n g e from Fossil Fuels to Renewable Energy Sources  2  1.1.3 Energy Efficiency  3  1.2 E N E R G Y U S E IN BUILDINGS  3  1.2.1 Potential for Reduction in Building Energy Consumption 1.3 T E C H N I C A L V E R S U S E C O N O M I C P O T E N T I A L F O R E N E R G Y E F F I C I E N C Y 1.3.1 Parameters of the Study  5 5 8  1.4 RESIDENTIAL A N D C O M M E R C I A L BUILDINGS  8  1.5 R E S E A R C H O B J E C T I V E S  9  1.5.1 General S c o p e of Work  10  1.5.2 Specific Areas of Investigation  10  1.5.3 Relationship between Embodied Energy and Cost  11  Chapter 2  T E S T BUILDING  DESCRIPTION  2.1 S T U D Y BUILDING T Y P E A N D SIZE  12  2.1.1 Building Location  12  2.1.2 Building Type and Size  12  2.1.3 Drawing List  13  2.1.4 Generalizability of Study Building  13  2.2 CLASSIFICATION O F PRIMARY BUILDING S Y S T E M S  14  2.3 D E S C R I P T I O N O F BUILDING S Y S T E M S  15  2.3.1 Sitework  15  2.3.2 Structure  16  2.3.3 Exterior Enclosure  16  2.3.4 Thermal Insulation of Exterior Envelope  17  V  2.3.5 Interior Enclosure  17  2.3.6 Finish Systems  18  2.3.7 Building Services  18  2.4 BUILDING O C C U P A N C Y  20  2.4.1 Area per Person  21  2.4.2 Period of Occupancy  22  Chapter 3  BUILDING LIFE-CYCLE  3.1 INTRODUCTION  23  3.2 G E N E R A L F U T U R E T R E N D S  23  3.2.1 Global Energy Futures  23  3.2.1.1 Energy efficiency  24  3.2.1.2 Natural gas  25  3.2.1.3 Renewable technologies  26  3.2.1.4 Depletion of fossil fuel reserves  26  3.2.2 Impacts on Buildings  27  3.2.3 Non Energy Related Trends  27  3.2.3.1 Reuse and recycling  28  3.2.3.2 Future scarcity of building materials  29  3.2.3.3 Improvements in technology  32  3.3 M A T E R I A L C H A N G E S IN O F F I C E BUILDINGS  33  3.3.1 R e a s o n s for Change  34  3.3.2 C h a n g e s in Office Accommodation Requirements  36  3.3.3 W o r k s p a c e  38  3.4 A L T E R N A T I V E F U T U R E S C E N A R I O S F O R S T U D Y BUILDING  38  3.4.1 Scenario 1  40  3.4.2 Scenario 2  41  3.4.3 Scenario 3  42  Chapter 4  INITIAL EMBODIED ENERGY  4.1 INTRODUCTION  45  4.2 E M B O D I E D E N E R G Y IN C O N S T R U C T I O N  45  4.2.1 Terminology  46  4.2.2 Control over Embodied Energy in the Construction Industry  48  4.2.3 Forms of Embodied Energy  49  4.3 E N E R G Y INTENSITY 4.3.1 System Boundaries  50 50-  vi 4.3.2 Location and Efficiency Factors 4.4 E N E R G Y A N A L Y S I S M E T H O D S  51 52  4.4.1 Input - Output Analysis  53  4.4.2 Process Analysis  54  4.5 P R E V I O U S S T U D I E S O F E M B O D I E D E N E R G Y  55  4.5.1 Energy Intensities  56  4.5.2 Embodied Energy of Office Buildings  58  4.6 M E T H O D O L O G Y T O C A L C U L A T E E M B O D I E D E N E R G Y 4.6.1 Construction Energy 4.7 E M B O D I E D E N E R G Y A N A L Y S I S A N D R E S U L T S  61 64 65  4.7.1 Analysis by Material Type  65  4.7.2 Analysis by Building System  68  4.8 VERIFICATION O F R E S U L T S  71  4.8.1 Quantity take-off Verification Methodology  71  4.8.2 Quantity take-off Verification Results  72  4.8.3 Relationship between Embodied Energy and Costs  72  Chapter 5  RECURRING EMBODIED E N E R G Y  5.1 INTRODUCTION 5.1.1 Methodology to Calculate Recurring Embodied Energy 5.2 R E S U L T S O F R E C U R R I N G E M B O D I E D E N E R G Y A N A L Y S I S  75 76 77  5.2.1 Impact of Improvement in Energy intensity  80  5.2.2 Detailed Analysis  81  5.2.3 Recurring Embodied Energy by System  82  5.2.4 Recurring Embodied Energy - Comparison by Scenarios  83  5.2.5 C h a n g e s in Recurring Embodied Energy  85  5.2.6 Cumulative Recurring Embodied Energy  87  5.2.7 Comparison with Other Studies of Recurring Embodied Energy  89  Chapter 6  OPERATING ENERGY  6.1 INTRODUCTION  90  6.2 O P E R A T I N G E N E R G Y O F O F F I C E BUILDINGS  90  6.2.1 Skin versus Internal Load Dominated Buildings  90  6.2.2 Building Energy Performance Index (BEPI)  91  6.2.3 Site and Source Energy  92  6.3 O P E R A T I N G E N E R G Y O F S T U D Y BUILDING 6.3.1 B a s e Building Mechanical and Electrical Systems  93 94  vii 6.3.2 Operating Energy of Base Building  Chapter 7  94  LIFE-CYCLE OPERATING E N E R G Y  7.1 INTRODUCTION  96  7.2 R E A S O N S F O R C H A N G E IN BUILDING O P E R A T I N G E N E R G Y  97  7.2.1 Replacement of Service Systems  97  7.2.2 C h a n g e s in Thermal Characteristics of Exterior Envelope  98  7.2.3 Decreases in Existing Service Systems Efficiency  98  7.2.4 C h a n g e s in Appliance and Equipment Loads  98  7.3 M E C H A N I S M S O F C H A N G E  99  7.4 O P E R A T I N G E N E R G Y C H A N G E S IN S T U D Y BUILDING - A L T E R N A T I V E S C E N A R I O S  101  7.4.1 Scenarios 1 and 2  102  7.4.2 Scenario 3 Change in Operating Energy as a Result of Conversion  102  7.5 L I F E - C Y C L E O P E R A T I N G E N E R G Y - R E S U L T S  Chapter 8  104  DEMOLITION E N E R G Y  8.1 INTRODUCTION  106  8.1.1 Relationship to Construction Energy  106  8.1.2 Categories of Demolition Energy  107  8.2 C O M P O N E N T S O F DEMOLITION A N D D I S A S S E M B L Y E N E R G Y  108  8.2.1 On-Site Energy  108  8.2.2 Material Transportation Energy  108  8.2.3 Worker Transportation Energy  109  8.3 ESTIMATION O F DEMOLITION E N E R G Y  109  8.3.1 On-Site Energy Calculation  110  8.3.2 Material Transportation Energy  112  8.3.3 Worker Transportation Energy  113  8.3.4 Total Demolition Energy  114  8.4 ESTIMATION O F D I S A S S E M B L Y E N E R G Y  114  8.5 C O M B I N E D DEMOLITION A N D D I S A S S E M B L Y E N E R G Y  115  Chapter 9  LIFE-CYCLEENERGY  9.1 INTRODUCTION  117  9.1.1 General Overview  117  9.1.2 Scenario 1 Life-Cycle Energy  119  9.1.2.1 Scenario 1 reduced building life-span  121  viii  9.1.3 Scenario 2 Life-Cycle Energy 9.1.3.1 Scenario 2 reduced building life-span 9.1.4 Scenario 3 Life-Cycle Energy  Chapter 10  123 124 125  R E D U C T I O N S IN L I F E - C Y C L E E N E R G Y  10.1 INTRODUCTION  127  10.2 S T R A T E G I E S T O R E D U C E O P E R A T I N G E N E R G Y  127  10.2.1 Methodology  127  10.2.2 Results  129  10.2.3 Comparison with other studies  131  10.2.4 Impact on Embodied Energy  132  10.2.5 Relative Importance of Embodied Energy as Operating Energy Efficiency  133  Improves 10.3 S T R A T E G I E S T O R E D U C E E M B O D I E D E N E R G Y  136  10.3.1 Reductions in the Energy Intensity of Building Materials - Direct Energy  137  10.3.2 Reductions in the Energy Intensity of Building Materials - Indirect Energy  137  10.3.3 C h a n g e s Resulting from Material Substitution  138  10.3.4 Potential for Energy Reduction through Material Substitution  140  10.3.5 Reduction in Embodied Energy through Material Quantity Reduction  142  10.3.6 Reduction in Embodied Energy through Material Substitution and Reduction  145  10.4 R E D U C T I O N S IN DEMOLITION A N D D I S A S S E M B L Y E N E R G Y  146  10.5 T O T A L R E D U C T I O N IN L I F E - C Y C L E E N E R G Y  146  Chapter 11  SUMMARY, CONCLUSIONS, RECOMMENDATIONS  11.1 S U M M A R Y O F FINDINGS  149  11.1.1 Embodied Energy  149  11.1.1.1 Reductions in embodied energy 11.1.2 Operating Energy  150 150  11.1.2.1 Reductions in operating energy  151  11.1.3 Demolition and Disassembly Energy  151  11.1.4 Life-Cycle Energy  152  11.1.5 Other Results  153  11.2 C O N C L U S I O N S  155  11.2.1 Current Levels of Energy U s e and Potential for Reduction  155  11.2.2 Importance of Operating Energy  156  11.2.3 Importance of C h a n g e s Over Time  157  11.3 R E C O M M E N D A T I O N S F O R P R A C T I C E A N D F U T U R E R E S E A R C H  158  IX  11.3.1 Energy Analysis at Building Scale  158  11.3.2 Investigation of Rates of C h a n g e in Energy Efficiency  158  11.3.3 Rates of Replacement  159  11.3.4 Energy Efficiency and Efficiency of Accommodation  159  References  1 6 1  Appendix 1  Base Building Drawings  1 6 5  Appendix 2  Scenario 3 - Residential Building Drawings  171  Appendix 3  Previous Studies of Embodied Energy  1 7 3  Appendix 4  Materials Take-Off  176  Appendix 5  Formulae to Calculate Recurring Embodied Energy  187  X  List of Tables 1.1  Greenhouse gases; origins and contribution to global warming  2  1.2  Energy consumption by economic sector  4  2.1  Primary building systems  15  2.2  Insulation values of exterior envelope assemblies  17  2.3  Area per office worker in selected c a s e study buildings  21  3.1  Scenario 1 - Major changes during building life span  41  3.2  Scenario 2 - Major changes during building life span  42  3.3  Scenario 3 - Major changes during building life span  43  4.1  Major previous studies of energy intensity and embodied energy  56  4.2  Comparison of chosen energy intensities of major materials with previous studies  58  4.3  Comparison of initial embodied energy studies of office buildings  59  4.4  Energy intensities from previous studies applied to study building  61  4.5  Example section of materials take off  62  4.6  Initial embodied energy of study building  65  4.7  Initial embodied energy and m a s s by material type  65  4.8  Initial embodied energy by building system  69  4.9  Structural systems embodied energy from previous studies  70  4.10  Comparison of calculated building cost with published cost  72  4.11  Comparison of initial embodied energy and capital cost  74  4.12  Comparison of initial embodied energy and capital cost of materials  74  5.1  Initial and recurring embodied energies (100 year lifespan)  78  5.2  Initial and recurring embodied energies (50 year lifespan)  79  5.3  Recurring embodied energy comparison of 50 and 100 year life-spans  79  5.4  Impact of improvements in energy efficiency of materials and increased recycling  81  5.5  Recurring and initial embodied energy by building system  82  6.1  Range of BEPIs from previous studies  92  6.2  B a s e building mechanical and electrical systems and loads  94  6.3  Details of operating energy consumption of base building  95  6.4  Comparison of study building operating energy breakdown with other studies  95  xi  7.1  Potential impacts on operating energy of life-cycle changes in study building  102  7.2  Comparison of energy use by building type  103  7.3  Life-cycle operating energy - 1 0 0 year life-span  104  8.1  Determination of on-site energy rate for office building demolition  111  8.2  Energy to move 1 tonne of material 1 km, figures from previous studies  113  8.3  Demolition energy  114  8.4  Disassembly energy  115  8.5  Combined demolition and disassembly energy  116  9.1  Life-cycle energy of study building based on 100 year lifespan  117  9.2  Comparison of scenario 1 L C E with building replacement scenario  121  9.3  Comparison of scenario 1 L C E with building replacement scenario  122  9.4  Comparison of scenario 2 L C E with 30 year building replacement scenario  125  9.5  Comparison of scenario 1 L C E with 50 year building replacement scenario  125  10.1  Strategies to reduce operating energy  129  10.2  Impact of energy reduction strategies on total annual building operating energy  131  10.3  Impact of strategies to reduce operating energy on embodied energy  133  10.4  L C E of study building - alternative operating energies  134  10.5  Substitution of materials in study building  140  10.6  Results of materials substitution strategies  141  10.7  Comparison of embodied energy of alternative concrete structural systems  143  10.8  Results of materials reduction strategies  144  10.9  Results of materials reduction and substitution strategies  146  10.10  Reductions in total life-cycle energy  147  11.1  Embodied energy summary  149  11.2  Reductions in embodied energy summary  150  11.3  Operating energy summary  150  11.4  Reductions in operating energy summary  151  11.5  Demolition and disassembly energy summary  152  11.6  Reductions in demolition and disassembly energy summary  152  11.7  Life-cycle energy of study building based on 100 year life span  153  11.8  Comparison of figures with and without allowances for changes in energy efficiency  157  xii  List of Figures 4.1  Conceptual diagram of the manufacturing process of a building material  48  5.1  Recurring embodied energy - scenario 1  85  5.2  Recurring embodied energy - comparison of scenarios  87  5.3  Cumulative recurring embodied energy  88  9.1  Life-cycle energy - comparison of scenarios  119  9.2  Scenario 1 life-cycle energy summary  120  9.3  Scenario 2 life-cycle energy summary  124  9.4  Scenario 3 life-cycle energy summary  126  10.1  Ratio of operating energy to embodied energy  136  1  Chapter 1 INTRODUCTION  1.1 INTRODUCTION There  is increasing public awareness of the seriousness of the numerous  negative  environmental stresses now threatening the ecological health of the planet. Many people also appreciate that certain of these pressures are beginning to imperil humankind's very existence. The most serious threats we face today are unlike any environmental crises previously experienced; they are of such magnitude that their solution will require fundamental economic, social and cultural transformations. These changes will involve a profound re-evaluation of society's relationship to the natural world, which, if successful, will pave the way to achieving a sustainable society. Global warming and associated climate change are widely recognised as being the most serious and pressing of current negative environmental pressures. In 1990 a panel of forty-nine Nobel-prize-winning scientists appealing to the President of the United States to implement legislation to curb greenhouse-gas emissions, stated that "global warming has emerged as the most serious environmental that future generations  threat of the century...only  by taking action now can we insure  will not be put at risk. "(Leggett 1990)  1.1.1 Fossil Fuels and Global Warming A key contributing factor to the climate change associated with global warming is the use of fossil fuel energy sources. Fossil fuels currently account for more than 9 0 % of global energy consumption. (BP 1994) Carbon dioxide emissions are primarily generated by the burning of fossil fuels; coal, oil and natural gas.  2  Table 1.1 Greenhouse gases; origins and contribution to global warming in the 1980s Greenhouse Gas  Principal sources  Carbon dioxide  Fossil fuel burning  C F C s , H F C s and H C F C s Methane  Nitrous oxide  Deforestation Industrial uses Rice cultivation Enteric fermentation G a s leakage Biomass burning Fertilizer use  Contribution to global warming 77%  42%  23%  13% 24% 15%  6%  Fossil fuel combustion Source: Leggett 1990 The contribution to global warming from tropospheric ozone is also significant but is difficult to quantify  1.1.2 Change from Fossil Fuels to Renewable Energy Sources Given the extent of the contribution of fossil fuel combustion to global warming any solution will clearly have to address this source. Because of their key role in global warming and because fossil fuels are a non-renewable resource, current rates of use are unsustainable and cannot continue indefinitely. A sustainable future for humanity will ultimately have to be based on cleaner renewable energy sources. If such a future is to be attained fundamental to economic structures and social institutions will be be necessary. However existing economic and industrial systems will require considerable time to change from a fossil fuels to renewable energy sources. Initial efforts to implement this change must concentrate on reducing overall energy consumption for two reasons: •  To minimize the impact of climate change by slowing the rate of global warming, and thus gain time for the transition to be made to renewable energy sources.  •  Because reduced energy consumption, along with developing new renewable energy sources, will inevitably have a major role to play in a sustainable future. At current high levels of consumption simply switching from fossil fuels to renewable energy sources would have enormous environmental impacts. For example to provide even half of current U S  3 energy requirements would necessitate the commitment of almost 2 5 % of land in the United States to solar energy systems. (Leggett 1990)  1.1.3 Energy efficiency The most direct and acceptable way to reduce overall energy consumption is through increased energy efficiency, "...improvements economy - are almost universally  in energy efficiency  - across all sectors of the  seen as the most obvious and most effective response  to  the problem of global warming." (UK House of C o m m o n s Energy Committee) By reducing the amount of energy required for various functions within the economy the feasibility of harnessing renewable energy sources is increased.  1.2 ENERGY USE IN BUILDINGS Energy consumption in buildings accounts for a significant portion of total energy use. Globally buildings account for approximately 4 0 % of overall energy consumption. In industrial countries this figure is even higher; reflecting both a greater range, size, and standard of building accommodation and the fact that more energy efficient industrial and transportation processes will result in lower figures for other economic sectors. For example in the UK, 5 0 % of energy consumption is used to service buildings (Vale 1991) while in the United States buildings use over 4 7 % of all energy. (US Dept. of the Environment, 1991) The energy used in buildings accounts for approximately 2 4 % of total energy consumption in B C . ( E M P R 1993) Because of greater energy use in other economic sectors the percentage of energy used in buildings in British Columbia is lower than the comparable figure for Canada as a whole, 3 1 % , which in turn is lower than that of other industrialized countries. The high proportion of energy intensive primary industries in both provincial and national economies and the fuel requirements involved in transporting goods over great distances result in larger  4  proportions of total energy being expended in the industrial and transportation sectors. (Although the relative percentages of energy consumed in the various sectors of the Canadian economy differs from other industrial countries and in some sectors is lower, overall per capita energy use in Canada is amongst the highest in the world)  Table 1.2 Energy consumption by economic sector Sector  Energy consumption BC  % ( PJ) Ontario  US  Canada  World  Industry Transportation  42.6 (417.0) 27.2 (266.1)  33.9(938.6) 24.9(688.5)  34.46 (2628) 25.57 (1950)  25 26  25 33  Residential Commercial  14.5(142.6) 9.5 (93.1)  18.7(517.5) 12.7(352.5)  19.56(1492) 11.66 (889)  20 27  15 25  Non-energy Military Total  6.2 (60.3)  9.8(272.0)  8.75 (667)  100 (979.4)  (2769.1)  100 (7626)  2 100  3 100  Sources; National Energy Board, 1991, B C Ministry of Energy, Mines and Petroleum Resources, 1993. U S D O E 1991, U N E P 1985. Note the commercial sector includes commercial and institutional energy uses and all service industries except transportation and energy utilities.  Table 1.2 above indicates the breakdown of energy consumption by economic sector. The figures for the residential and commercial sectors when combined, broadly represent energy use in buildings. To this figure must be added that portion of energy consumed by the industrial and transportation sectors of the economy to service buildings in those sectors. For example, approximately 5 % of all industrial energy in B C  (1.9% of total B C energy) is  consumed in lighting and heating industrial buildings. It is important to recognize when reviewing these statistics that the figures for the residential and commercial sectors deal only with operating energy, that is the energy directly consumed in buildings to provide heating, cooling, lighting etc. In addition a considerable amount of industrial activity is devoted to the processing of materials and the manufacture of products for the construction of buildings. Energy consumed by the construction industry to assemble  5 building components and erect buildings is also counted as part of the industrial sector's overall energy consumption.  1 . 2 . 1 Potential for Reduction in Building Energy Consumption As a result of relatively modest recent improvements in the energy efficiency of buildings, this area currently offer greater energy conservation potential than almost any other economic sector. The fragmented nature of the construction industry however, means that overall improvement in performance can only be achieved through independent initiatives taken by very large numbers of individual building owners, architects, and contractors. Progress in increasing energy efficiency in the construction sector has also been limited by the slow replacement rate of buildings when compared, for example, to automobiles or industrial equipment. Replacement of the existing building stock in the UK, takes place at a rate of less than 0.5 percent each year compared to 12 percent for automobiles. (Pawley 1990)  1.3 TECHNICAL VERSUS ECONOMIC POTENTIAL FOR ENERGY EFFICIENCY The issue of energy use in buildings, in addition to having considerable environmental impacts, clearly also has both economic and social dimensions. Reductions in energy use in buildings, while in some cases requiring an increased in initial capital expenditure, are invariably accompanied by overall life-cycle cost savings. These cost savings may be substantial, and by themselves are capable of providing a powerful incentive for improving energy efficiency. Nevertheless many existing energy policies and tax codes are biased against energy efficiency and encourage and subsidize increased reliance on fossil fuels. Emphasis has traditionally been on finding new sources of energy supply rather than on increasing efficiency to maximizing energy services. Until recently, cost savings, which operate at both macro and micro-economic levels, along with concern over perceived imminent scarcity of resources, have  6 been the driving forces behind almost all energy conservation initiatives. Unfortunately energy prices regularly fluctuate and the economic impetus for energy efficiency can become less compelling as prices fall. Current record low oil prices threaten many existing efficiency programs which are based primarily on economic criteria. Historically initiatives to improve energy efficiency or to develop alternative fuel sources can be closely correlated to fluctuations in the price of fossil fuels. A s the price of oil increases an economic incentive to reduce consumption and seek alternative energy sources is created. However if prices drop, as they have done dramatically in 1973, 1981 and 1985, the incentive for conservation disappears. "Since 1986 when oil prices fell back below $20 per barrel, the move toward more efficient homes, cars, and factories that began in the mid-seventies  slowed  to a crawl." (Flavin and  Lenssen 1990) A n additional obstacle to investment and research into alternative energy sources are government subsidies that encourage the continued reliance on traditional  energy  sources. U S federal government subsidies to energies amounted to more than $44 billion in 1984. (Flavin and Lenssen 1990) Thus while the existence and periodic application of numerous energy conservation programs indicates a technical potential for reductions in energy consumption, for economic reasons the overall goals of these programs are often not achieved. At any given time a discrepancy can exist between the technical potential for energy efficiency and the economic incentive to realise that potential. While recognizing that sound economic grounds to encourage energy efficiency do exist, it is the author's belief that in the current context of severe threats to global environmental support systems, neither energy conservation policies, nor appropriate levels of energy consumption can be determined using conventional economic accounting methods. Energy efficiency programs must be based on technical potential, that is the maximum possible achievable energy  reductions,  rather  than  on  economic  potential,  what  is financially  expedient.  Alternatively accounting systems which internalize environmental costs may be implemented.  7  Flavin and Durning state that while in the nineties energy efficiency may offer an economic opportunity, more importantly it has also become an environmental necessity.  (Flavin and  Durning 1988) In the context of today's construction industry a focus on the technical rather than economic potential for energy conservation may be seen as unrealistic. It can be argued that economic concerns are one of the major determinants of the building design and construction process and that proposed changes not based on cost criteria have little chance of being implemented. However decisions based on economic criteria are made within an overall social and regulatory context which involves more complex issues than simple market forces. Much of the progress, although admittedly limited, that has been made in improving energy efficiency has come about through government and municipal regulation and initiative (e.g. City of Vancouver Energy By-law). If the primary reasons for attempting to reduce energy consumption are environmental concerns,  these  concern  must  be  addressed  in  any  accounting  procedures  used.  Unfortunately "free market" economics as currently practiced provides no practical method of calculating or assigning value to environmental functions. A s with economic arguments, the finite nature of fossil fuel resources can no longer be considered a singularly compelling force to drive efforts towards energy efficiency, nor to set appropriate overall levels of energy consumption. Ultimately all fossil fuel resources are subject to physical limits, but an even more fundamental limitation to their continued use is the atmosphere's capacity to absorb the associated carbon emissions. The limiting factor is the environment's "sink" function rather than in its supply function. Combustion of the remaining fossil fuel resources would raise carbon dioxide concentrations to ten times current levels, clearly an unacceptable position considering the mere doubling of levels that are now proving to be potentially disasterous. (Flavin and Lenssen 1990)  8  1.3.1 Parameters of the Study The position, outlined above, is thus seen a s a recognition that changes in the social, economic and legislative context in which architecture is practiced will be required in order to solve environmental problems arising from the use of fossil fuel energy sources. Incentives based on cost savings or resource depletion alone cannot be relied on to provide the driving force in efforts to mitigate negative ecological impacts. The present study is therefore grounded in an analysis which focuses exclusively on energy measurement rather than cost accounting; although costs are used in certain sections for verification purposes. This approach is not seen a s an attempt to avoid the reality of the economic forces that currently drive all sectors of the economy. Rather it is based on the assertion that market economics a s currently practiced provides no practical method of calculating or assigning value to environmental functions. If the primary reasons for attempting to reduce energy consumption are environmental concerns the use of accounting systems which do not take them into account are clearly inappropriate.  1.4 RESIDENTIAL AND COMMERCIAL BUILDINGS Considering the larger proportion of energy used in residential buildings, this sector might be seen to offer greater potential for energy conservation and be a more appropriate area to investigate. However, the commercial sector and specifically office buildings were chosen for this study, for a number of reasons:. •  Although the residential sector accounts for greater energy use, this consumption is distributed over a much larger number of smaller buildings. At the individual building level the commercial sector offers greater opportunity to reduce building energy consumption.  9  •  Worldwide energy use in commercial buildings is increasing at a greater rate than residential consumption. (Flavin and Durning 1988)  •  Traditionally architects have had little involvement in most residential construction. In Canada the legislative requirement that an architect be involved in design does not extend to single family home construction, which accounts for by far the largest portion of the residential building stock. Architects have far more opportunities to influence energy use and consumption patterns within the non-residential building sector.  •  The existence and success of practical measures such as the R-2000 program attest to the . progress that has been made in achieving energy reduction targets in the residential sector. Similar initiatives, such as the C-2000 program, are only now beginning to emerge in the commercial sector.  1.5 RESEARCH OBJECTIVES Much of the work to date which seeks to address environmental issues in relation to the practice of architecture has, for various reasons, been either of a very general nature, suggesting overall goals and broad strategies, or'extremely specific and focused in detail on a single aspect of construction. Both types of research are necessary and can provide valuable direction for design. Overall views of the building industry and it's environmental impacts can guide the formulation of policy at governmental levels and result in new codes standards and regulations. The more detailed and focused work, for example, concerning the environmental impacts of particular building materials, can provide data to designers that can be used in making specific choices on individual projects. What has tended to be missing however, is work which collects and combines the detailed fine-grained research and presents it, in the context of specific buildings, in a format that can indicate the relative order of magnitude of importance of the  10  individual issues being studied. This study attempts to take such a holistic view of the issue of energy use in commercial office buildings.  1.5.1 General Scope of Work The thesis will: •  Examine, through the analysis of a study building, the relative components of life-cycle energy consumption of commercial buildings. Life-cycle energy represents the total amount of energy accounted for by a building during the course of its life and will be studied under the categories of:  •  •  Operating energy  •  Embodied energy  •  Construction and demolition energy  Attempt to incorporate into the analysis issues relating to the effect of time on certain of the key energy issues.  •  Investigate the potential that exists for reducing life-cycle building energy consumption.  •  Determine and prioritize the most appropriate strategies to reduce life-cycle energy.  1.5.2 Specific Areas of Investigation Traditionally efforts to reduce energy consumption in buildings have focused almost exclusively on the area of operating energy. Recent studies however, have shown that embodied energy may represent a significant portion of total building life-cycle energy, particularly in the case of buildings with short life-spans or high rates of maintenance and refurbishment such as commercial office buildings. (Forintek 1994) One of the major tasks of this thesis project will be to arrive at an understanding of the significance of embodied energy in the overall building context. A s a result of the previously  11  discussed emphasis on operating energy, many building professionals have an intuitive feeling for the particular levels of operating energy use associated with different building types. Many computational tools exist which can be used at building design stage to predict energy consumption levels in completed buildings. Building owners and managers, through their familiarity with utility bills, also tend to have an appreciation of current levels of operating energy consumption. A comparable understanding of the issues involved in building embodied energy does not exist and must be developed as a prelude to formulating comprehensive energy conservation strategies. O n e the primary aims of this thesis will be to examine these issues in an attempt to develop an intuitive understanding of the subject. The life-cycle energy analysis of the building will take into account future changes in the embodied energy content of buildings materials due to increases in the energy efficiency of the industries which supply those materials. The impact of time on many of the energy issues relating to buildings is considered to be important; research can demonstrate significant changes in both embodied and operating energy of buildings over the last 20 years. This is an area of investigation few previous studies have addressed but one which may have a considerable effect on the life-cycle energy of the study building.  1.5.3 Relationship between Embodied Energy and Cost A further study of the embodied energy figures and their distribution will be undertaken to determine if a correlation exists between embodied energy and dollar costs. There are economic reasons to suggest that such a correlation should exist as the cost of processing and manufacturing energy represents a important element in total production costs. Materials with higher embodied energy content may be expected to also therefore have a higher material cost. If a clear and identifiable relationship can be established between material cost, and embodied energy content, cost data may then be substituted for energy data in embodied  12  Chapter 2 TEST BUILDING DESCRIPTION  2.1 STUDY BUILDING TYPE AND SIZE The energy analysis described in Chapter 1 is carried out through the analysis of a study building. This is not a real building and exists only in the form of drawings and computer files.  2.1.1 Building Location The study building is designed for a location in the Lower Mainland of British Columbia. This area of the province, located at 49° north latitude on the western coast of North America, has a temperate climate. The average January temperature is 2°C, the July average 17°C; there are 3031 (18°C) heating degree days per year and an average of 308 frost free days.  2.1.2 Building Type and Size The study building is a generic 5-storey office building (Group D occupancy) of noncombustible construction, designed to comply with Section 3.2.2.32(1). & (2) of the National Building Code for Canada 1990. The building is representative of typical non-high-rise office buildings found in may areas outside of central business districts throughout Canada. The building is oriented on an east - west axis and is located on a 0.713 hectare (95m x 75m) site bordered on the south side by a municipal street. All required utilities and services are assumed to be available from the adjoining street. All necessary site work associated with the building, access roads, services etc., is included in all embodied energy calculations. The main entry to the building, located on the south elevation, leads to an elevator, stair and washroom  13  core centred on the north elevation. Stair towers are located at the east and west ends of the building. These stairs are primarily intended for fire escape purposes but may also be use for normal circulation between floors. In addition to the five above grade floors the building has a one level of below grade parking. The total above grade floor area of the building measured to the outside face of the exterior walls is 8015 m . Net lettable area is 6735 m giving a net,to gross ratio of 84%. The area of 2  2  underground parking is 1570 m , providing 44 car parking spaces. 2  2.1.3 Drawing list The building is described and detailed in the following drawings: •  Drawing A1  Site Plan  •  Drawing A 2  Basement Floor Plan  o  Drawing A 3  Ground Floor Plan  •  Drawing A 4  Typical Floor Plan  •  Drawing A 5  Elevations  All drawings are included in Appendix 1  2.1.4 Generalizability of Study Building Although the study building is designed, and energy analysis carried out, for the specific location described above. The design of the building is only locationally specific in terms of responding to local building code requirements for particular levels of thermal insulation. In all other respects the building is similar to many others built in all parts of Canada, and indeed in many other countries with temperate climates. Occupancy patterns and operational practices,  14  such as control of indoor environmental conditions, maintenance and replacement schedules are equally generalizable. Specific locational data relating to climate is a major component of the modeling of the buildings operating energy performance, other geographic locations could result in significantly different results. A n operating energy analysis carried out on two identical office buildings, similar to the study building, for locations in Vancouver and Toronto showed a difference of 68 % between the annual operating energies of the two buildings. (Forintek 1994) A similar disparity of this order of magnitude does not exist in the case of embodied energy. Limited data and the fact that many building materials are sourced nationally, and in certain cases internationally,  makes it difficult to provide analysis that is locationally specific. Where  specifically regional data on energy intensity of materials is available, for example the Forintek study of concrete production, the variations are insignificant. The energy intensities for concrete production in Vancouver and Toronto differ by less than 5 percent. The considerable variation in operating energy makes the overall analysis and results specific to the Lower Mainland location. However if adjustments to the operating energy component can be made based on local data life-cycle energy can be readily calculated for other locations.  2.2 CLASSIFICATION OF PRIMARY BUILDING SYSTEMS A structure such as the study building is a complex assemblage of many individual construction materials and components. To fully document and analyse the building, a method of classification must be devised that breaks the total structure down into smaller more manageable categories and sub-categories. The method chosen is partly based on a process of organization described in "How  Buildings  Learn", and uses some of the same categories. (Brand 1994) Brand's system is in turn an  15 expansion of a method of classification of building elements according to their typical lifespans. (Duffy 1992)  Duffy's contention is that "....there isn't such a thing as a building.  building properly conceived  is several layers of longevity  of built components."  A  Thus Duffy  defines four layers of elements and assemblies, which he calls Shell, Services, Scenery and Set, each typically having a different life-span. This classification scheme deals mainly with the interiors of buildings and is less concerned with architectural and structural systems, for example exterior cladding and building structure are combined in a single section. For the purposes of this study the original four categories are amended and expanded to give six sections which will be referred to as building systems. A system in this context describes "a set of connected  things or parts that form a whole or work together". (OED) Table 2.1 below lists,  and describes the components of the six systems. Table 2.1 Primary building s y s t e m s SYSTEM Site Structure Exterior e n c l o s u r e Interior e n c l o s u r e Finishes Services  C o m p r i s e d of: Site preparation, site services, a c c e s s roads, paving etc. All elements designed to support and transmit dead, live loads and lateral loads. Columns and beams, loadbearing walls, floors etc. Exterior cladding elements designed to provide protection from weather and prevent heat loss. Walls, windows, roof etc. Elements designed to enclose and separate interior spaces, e.g. partitions and ceilings. Stairs are also included in this section Applied finishes Mechanical systems, e.g., H V A C (Heating, ventilation and air conditioning), plumbing, fire protection (sprinklers). Electrical systems  2.3 DESCRIPTION OF BUILDING SYSTEMS Each of the primary building systems is briefly described. Additional and more comprehensive details of these assemblies are provided in appendix 4.  2.3.1 Site Systems This section covers all site components, access roads, sidewalks, paved surfaces and site lighting. A c c e s s roads through the site to the entry to the underground parking are  16  conventional asphaltic concrete. Sidewalks are of concrete construction. Also included are the supply of services to the building (water, gas, telephone, electricity and storm and sanitary sewers) from the adjoining public street. All services runs through the site are assumed to be under-ground.  2.3.2 Structure Structure includes all elements, columns and beams, loadbearing walls, floors etc., designed to support and transmit dead, live and lateral loads. The building structure is a reinforced castin-place concrete frame, consisting principally of columns on a 7.5 x 7.5m grid supporting concrete slab and slab-band floors. Cast-in-place concrete walls walls are provided to the below-grade parking level, the elevator and stair tower cores and in other locations as shear walls. Foundations are reinforced cast-in-place concrete pads to columns and strip footings to load-bearing walls.  2.3.3 Exterior Enclosure Includes all cladding elements designed to provide protection from weather and prevent heat loss; principally walls, windows and roof. •  Framed walls are brick clad, steel stud framed infill panels with 75mm polystyrene insulation and "peel and stick" air barrier applied to the exterior face of reinforced gypsum board sheathing. Shear walls are similar with the insulation and air barrier applied to the reinforced concrete. The interior finish of both wall types is 12mm gypsum board.  •  Windows are confined to the north and south elevations where they form a continuous band between structural columns 1.8m high at each floor. Windows have thermally  broken  17  aluminum frames and are double glazed. This section also includes exterior doors, all of which are aluminum framed and glazed. •  The roof assembly includes all components located above the reinforced concrete structural deck; membrane, insulation, air barrier and all necessary flashings, cants etc. Tapered insulation roof crickets are used to provide slopes to drains.  2.3.4 Thermal Insulation of Exterior Envelope Table 2.2  below provides details to the thermal insulation values of the various envelope  assemblies. A s previously discussed these values are intended to comply with the City of Vancouver Building By law. Table 2.2 Insulation v a l u e s of exterior envelope a s s e m b l i e s Assembly  RSI value  A r e a of assembly  Percentage of total envelope  m2.oC IW 2.22 3.14 3.27 0.30  m 1572 1455 1206 1085 1556  %  Roof Framed walls Shear walls Glazing Underside of ground floor slab and walls to basement conditioned space Total  6874  100  22.87 21.17 17.54 15.78 22.64  2.3.5 Interior Enclosure Includes all interior space enclosing assemblies and components. The main sub-systems are; partitions  (non-structural  interior walls), suspended ceilings and door assemblies. Also  included are interior stair accessories, guardrails etc. (the stairs themselves are accounted for under structural systems). It was decided that partition assemblies would include all elements except painted finishes. G y p s u m wall board is therefore considered to be a part of interior enclosure systems and not finish systems. O n this basis gypsum furring to concrete shear  18  walls and elevator shafts is also included in this section with only the painted finish reported under finish systems. •  Ceilings: Acoustic ceiling tile and T-bar suspended ceilings are provided to all office areas with painted gypsum board ceilings to washrooms and the main entry lobby. There are no ceilings in service rooms and stair towers.  •  Partitions: Two types of partition are included; a 2 hour fire rated partition, and a non-rated partition. The rated partitions are 3.4 m high and extend to the underside of the structural slab while the non-rated partitions are 2.7 m high and stop at, and are fixed to the suspended ceiling assembly. The ratio of partition to floor area is 1 linear metre of partition per 5.7 m  2  Total length of partitions is 1400 m with rated partitions accounting for 1 3 % of  the total.  2.3.6 Finish Systems Consists of finish materials to all exposed interior surfaces, primarily, walls, floors and ceilings. •  Walls: Paint finish to all gypsum board and concrete walls. Ceramic tile finish to washroom walls  « Floors: Granite tiles to entry lobby, ceramic tiles to washrooms. All other areas except the basement and stair towers have carpet and sheet vinyl finishes. No floor finish layout was designed but it is intended that carpet will predominate with sheet vinyl only used in selected areas such as utility rooms. Carpet is therefore assumed to cover 9 5 % of the areas in question. •  Ceilings: All gypsum board ceilings have a painted finish  2.3.7 Building Services Systems  19  Includes all primary and secondary environmental control and servicing systems required in the building. Service systems outside of the building are included in the sitework section. The major sub-systems are mechanical, electrical and conveyance services. Mechanical •  H V A C : Variable air volume system (VAV) with supplementary hydronic baseboard heaters.  •  Plumbing: Includes hot water heaters and associated hot and cold water supply piping to plumbing fixtures and waste water disposal piping from fixtures Roof drains and piping systems to carry rainwater are also included. Supply piping is primarily copper with some polyethylene, waste disposal piping is P V C or A B S .  •  Fire protection: A sprinkler system is included in the building consisting of steel piping and sprinkler heads  Electrical o Service and distribution: Includes a 30 K V A transformer and all necessary panel boards. Distribution is via conventional wiring carried in steel conduit, junction boxes, and cable trays. •  Lighting: Lighting to office areas employs conventional lay-in fluorescent fixtures. Compact fluorescent fixtures are used in the main lobby area and in washrooms.  •  Power: To accommodate plug loads duplex receptacles are provided at a density of one per 4.7 m of lettable area. A combined telephone and computer outlet is provided for every 27 2  m . Lighting control to the base building is by conventional manual electrical switches. 2  Conveyance •  Elevators: Two 12 person hydraulic elevators are provided, one elevator serves all of the above grade floors (5 stops) the other serves all above grade floors and the basement parking level (6 stops)  20  2.4 BUILDING OCCUPANCY A number of studies have identified that considerable care needs to be taken in the comparison of the energy intensities of materials. (Cole & Rousseau 1992, Tucker and Treloar 1994) "Building materials can be unfairly prejudged on the basis of their unit energy in comparison performance  to other materials characteristics  because  intensity  the unit energy intensity does not convey  of the material." (Tucker and Treloar 1994)  the  For example a  comparison between concrete and aluminum on the basis of energy intensity alone would suggest that concrete is several orders of magnitude less energy intensive and therefore "better" than aluminum. However this argument suggests that the materials are functionally comparable and does not recognize that, in the context of construction industry practice, the uses a kilogram of aluminum are entirely different to those of a kilogram of concrete. Building designers cannot make choices of this type based on embodied energy. Much the same reasoning can be applied to the energy consumption of a complete building. Comparisons can be unfair and meaningless if the "performance" of the buildings is not the same. The performance of buildings is difficult to define but at its core must contain some idea of accommodating human activity and some measure of the extent of building fabric required to house a particular level of activity. Buildings provide necessary shelter for a range of human activities, this positive benefit to society must be in some way quantified in order that it can be offset against the negative environmental consequences of buildings. There are two components to the "performance efficiency" of buildings; •  the number of people accommodated, specifically the area per person, and;  •  the times during which the building is occupied.  21  The performance of buildings will therefore vary greatly depending on the type of activity they accommodate. It follows that it is only meaningful to compare and contrast buildings of similar type; office buildings with office buildings or schools with other schools.  2.4.1 Area per Person It is difficult to estimate the area required per office worker to carry out normal officer routines. C a s e studies reported by Duffy give a range from 9.3 m to 48.8 m per employee for some 2  2  recent European examples. (Duffy et al 1993) A U.S. report by N A I O P (National Association of Industrial and Office Parks) gives high and low figures of space per office worker of 25 m and 2  21.6 m . Area per worker will also vary according to status, managers averaging 38.9 m and 2  clerical workers 20.2 m  2  2  European densities appear to be somewhat higher than those in  North America, a U K study (Energy Efficiency in Offices - Guide 35. Department of the Environment, Energy Efficiency Office 1993) indicates between 5 and 30 m per person with 2  the majority of offices in the range of 8 to 16 m per employee. 2  Table 2.3 A r e a per office worker in selected c a s e study buildings Building  Building  Average  No. of  area  area per  workers  Source  worker m A S H R A E 90.1 default values from Section 13 B C Hydro Commercial Building Stock study 1993 Volvo C a r Corp., Goteburg, Sweden Spie Batignolles, France P A Consulting Group, London, England Olivetti, Bari, Italy Greenpeace UK, London, England Glaxo Pharmaceuticals ltd., London, England Regional Centre - high Regional Centre - low Study Building (gross area)  m' 25.6(c) 19.1  33,000  37  " 60,000 9290 13,000 1858 16,257  19 8 24 16 20  900 3,200 1,200 550 85 800  24 22 8015  25.6  313  a a a a a a b b ASHRAE 90.1  Sources (a) The Responsible Workplace - The Redesign of Work and Offices, Duffy, Laing, Crisp (1993)  22  No indication is given as to whether the areas are gross or net lettable (b) America's Future Office Needs - Preparing for the year 2000, National Association of Industrial and Office Parks (NAIOP) (1990) It is assumed from the text that areas are net lettable (c) Based on gross area (conditioned area) rather than net lettable area  2.4.2 Period of Occupancy A s the building is designed to comply with the operating energy provisions of A S H R A E 90.1 the figures in this document were deemed the most appropriate and were used to calculate the number of building occupants. These figures were also used in the D O E - 2 computer calculations of operating energy. Based on a conditioned area of 8 0 1 5 m a total of 313 office 2  workers would be accommodated at 1 0 0 % occupancy levels. (In reality, the building will rarely be fully occupied, at any given time workers will be away from the building on other business or on vacation or sick leave. Nor do office buildings typically operate on a 24 hour basis; normal office hours are from 8am to 5pm on weekdays at other times the building will not be occupied. Allowances for both of these factors are made in the D O E - 2 computer model.)  23  Chapter 3 BUBLDBNG L S F E - C Y C L E  3.1 INTRODUCTION A major focus of the thesis is the investigation and determination of life-cycle energy. Implicit is the idea that the energy characteristics of buildings change over time, and that life-cycle energy cannot be calculated by simply projecting the initial energy characteristics of the building into the future without modification. This chapter is concerned with the dynamics of changes in office buildings over time and with future trends which may affect how and when these changes occur. Three alternative future scenarios are suggested for the study building. These alternative scenarios will be used in later chapters to calculate the life-cycle portion of each of the energy categories.  3.2 GENERAL FUTURE TRENDS In addition to considering the nature of future changes in buildings, the overall context in which those changes occur must be reviewed. In this general framework, economic, social and cultural forces operate to determine which buildings are built and how they are built. These forces will continue to be important in the future but in addition environmental concerns are likely to become increasingly important. It is therefore necessary to define a possible future context within which changes to the study building will take place.  3.2.1 Global Energy Futures In reviewing current environmental and economic trends a range of possible future outcomes can be proposed. A pessimistic outlook might project a "business as usual" continuation of  24  such current trends as global warming, ozone depletion, and resource scarcity, and foresee a collapse of existing social and economic institutions.  A more optimistic viewpoint,  while  recognizing the severity of many of these environmental problems, would also acknowledge that all are potentially soluble. Although fundamental changes may be required to existing economic systems and to social and cultural patterns,  if these changes take place a  sustainable future can be envisioned. Numerous scenarios have been put forward suggesting how a transition to a sustainable future may be achieved. O n e that deals with the phenomenon from the perspective of energy issues has been developed by the WorldWatch Institute and is described in Flavin and Lenssen (1994). This scenario, while recognizing the extent and difficulties of the changes required, offers a plausible alternative to an un-sustainable "business as usual" route to the future. The scenario has three main components each of which will have direct impacts on buildings: •  Increasing energy efficiency  •  Increasing use of natural gas (at the expense of other fossil fuels)  •  A gradual switch to renewable energy technologies  3.2.1.1 Energy efficiency Many analysts consider energy efficiency to be the key element in a transition to a sustainable energy future, "...improvements almost universally  in energy efficiency  - across all sectors of the economy - are  seen a s the most obvious and most effective response  to the problem  of  global warming." (UK House of C o m m o n s Energy Committee) By reducing the amount of energy required for various functions within the economy, both the feasibility of applying renewable energy technologies and the time available for such a transition are enhanced. The WorldWatch Institute Scenario requires that global energy efficiency double over the next 40 to  25 50 years. Between 1960 and 1987 the energy efficiency (measured in thousand dollars (1987 U S dollars) of gross world product per ton of oil equivalent of world primary energy) of the world economy has improved by approximately 25%, a rate of 0.75% per year. S o m e industrial countries have achieved rates of up to 2 % per year during the 70s and 80s. (Flavin and Durning 1988) Significant differences in efficiency currently exist within the global economy and there remains considerable potential for improvement. The German and Japanese economies are respectively twice and three times more energy efficient than equivalent U S economic sectors. (Vital signs 1992) This is in part due to these countries investing in new and more efficient technology during post-war reconstruction while the United States economy modernized and replaced out-dated industries more slowly. A similar effect may occur as thirdworld countries develop their economies and are able to by-pass outdated  industrial  technologies and develop highly energy efficient industrial systems.  3.2.1.2 Natural Gas Growth in the use of natural gas as an alternative to other fossil fuels will continue. This trend is driven both by environmental concerns about carbon dioxide emissions and major new gas discoveries in South and Central America, Indonesia and Russia. (Vital Signs 1992) Current known reserves appear to be sufficient to allow a doubling or tripling of natural gas use during the next 30 years and to sustain that level of use for several decades. Peak usage is anticipated by 2030, followed a sharp fall in consumption after 2050, with natural gas as a fuel being largely phased out by the end of the 21st century. The WorldWatch Institute Scenario sees natural gas as a transition fuel to a sustainable energy economy which will be based on renewable sources using hydrogen as an energy carrier.  26  3.2.1.3 Renewable Technologies Ultimately a sustainable future must be based on the use of renewable energy technologies. Neither nuclear fusion nor fission are seen as viable options. Solar, (both thermal and photovoltaics) wind and geothermal are projected to make significant advances as costs decline and commercial scale production begins. By 2025 each of these technologies is projected to be supplying 7% of total energy; this is as much energy as nuclear power currently provides. The bulk of this energy will be used to generate electricity, which will be distributed through the existing grid system, although the location of solar photovoltaic arrays on individual buildings will become common. Between 2025 and 2050 a 7 5 % increase in the energy available from renewable technologies is projected to make them the worlds second largest energy source, after natural gas. Ultimately by 2100 renewables are expected to provide 9 0 % of primary energy. The projected growth rates for renewable energy technologies may seem unrealistic however, they are in fact slower than the rates of increase in the supply of nuclear power in the 1960s and 70s.  3.2.1.4 Depletion of Fossil Fuels Reserves The future energy scenario described above has been developed in response to severe environmental impacts related to global warming and climate change and,' in particular, to energy related contributions to these phenomena. The realization that global warming and associated climate change are currently the most serious environmental threats  facing  humankind is a relatively recent development. Prior to the 1980s the potential future scarcity of fossil fuels was considered to be the most significant global energy problem. While there have been recent discoveries of new sources of fossil fuels and a reassessment of existing reserves, future scarcity at current rates of consumption remains a certainty. However recent research  27 into global warming has indicated that future scarcity is no longer the most important energy related environmental issue. The limiting factor is now seen as the planet's ability to absorb emissions associated with fossil fuel use; thus, the consequences of using remaining fossil fuel resources are seen to be much more serious than the eventual exhaustion of these reserves. Despite this major change of emphasis in relation to the environmental repercussions of energy use the practical solutions to both problems are essentially the same. The policy responses to future scarcity of fossil fuel reserves involved the implementation of precisely those strategies now proposed in response to the problem of global warming; increased energy efficiency and an eventual switch to renewable energy sources.  3.2.2 Impacts on Buildings Energy use in buildings is a key component of total global energy use. Most of the energy used in buildings  is currently  derived from  fossil fuels and changes in their  energy  use  characteristics will clearly play a role in the future scenario described above. The energy efficiency of the study building is anticipated to improve over time as new building codes require greater efficiency in the thermal performance of buildings and reductions in operating energy in response to the trends described. These new requirements will result in existing mechanical and electrical systems being replaced with newer and more energy efficient equipment. In addition, building envelope thermal performance is predicted to improve as cladding assemblies are periodically replaced. A s a result of general improvements in materials and equipment technology at any given time replacement components are expected to be more energy efficient than those existing in the building.  3.2.3 Non Energy Related Trends  28  In addition to the future energy scenario described above there are other future trends which will have impacts on the design, construction and operation of buildings. S o m e of these are responses to other environmental issues, for example increasing recycling of materials as a response to resource depletion. Others are economic, social and technological in nature and may or may not also be responses to environmental pressures. Improvements in the energy efficiency of manufacturing processes for example may be driven by initiatives to reduce pollution as much as by attempts to reduce costs.  3.2.3.1 Reuse and Recycling In response to diverse environmental pressures, reuse and recycling have emerged in recent years as a major phenomenon of life in industrial societies. In general terms recycling attempts to minimize and reduce environmental impacts through « Reducing consumption of raw material resources •  Reducing energy use  •  Reducing the quantity of material entering the waste stream  Although recycling is a common practice in many of the industries that supply building products, it has to date in Canada, with one or two notable exceptions, had little impact on the construction industry itself. Reuse and recycling in buildings may be thought of as a broad cover term to describe a number of distinct issues. These issues may be addressed at the level of materials and components or at the scale of complete buildings they include: •  Reusing materials and components in the same building or other buildings  e  Designing buildings for reuse of materials and components  •  Reusing complete buildings  •  Selecting and using materials which have a recycled content  29  •  Selecting and using materials which are capable of being recycled  The greatest potential impact in energy terms resulting from material reuse and recycling will be a decrease in recurring embodied energy. Reused and recycled materials will require less energy for material acquisition, processing and manufacture than is required for comparable new material. The potential for reuse and recycling is not consistent across all construction materials and components. A s a result the precise effects of increased reuse and recycling on the study building are difficult to determine and quantify. In this study a figure of a 0.2 percent per annum decrease in embodied energy is included in calculations to account for the impacts of reuse and recycling of materials and components.  3.2.3.2 Future Scarcity of Building Materials The future scarcity or unavailability of particular building materials is an issue which could potentially have a major impact on buildings. Increases in overall embodied energy could result for several reasons. •  The most readily available and easily accessible sources of a material are typically exploited first. Increasing scarcity of these sources will require greater energy to be expended in accessing less concentrated and conveniently accessible sources. The embodied energy of the material would thus increase as the material becomes scarcer. The impact of this trend may be lessened by future increases in the efficiency of extraction, acquisition and manufacturing technology.  *  In the event of supplies of a particular material being exhausted, it may be necessary to replace that material with a more energy intense material. For example large dimension sizes of softwood lumbar are increasingly difficult to obtain and have largely been replaced with engineered wood products which have a higher energy intensity, 10-15 MJ/kg for  30 engineered wood products, 5.8 MJ/kg for dimension lumber. (Although many engineered wood products have higher energy intensities they also typically have improved performance characteristics than their lumber equivalents.) To study the potential impact of materials and resources scarcity the major materials and categories of materials in the study building are briefly reviewed.  Concrete •  The primary raw materials for concrete; portland cement and aggregates are in abundant supply in most parts of the world. These materials are usually sourced locally and there would appear be little danger of even long term scarcity. In addition, flyash, a waste product from power stations, is now commonly used to replace a portion of the cement in concrete mixes.  Steel •  In the short term there appears to be little possibility of resource scarcity of iron ore. Nevertheless with worldwide production of approximately 552 million tons of pig iron in 1990 (Vital Signs 1992) depletion of raw materials reserves will inevitably occur if current rates of extraction continue. However except over a long time period this situation is unlikely to occur because of the increasing use of recycled content in steel production. Currently 2 5 % of world steel production is derived from scrap and this percentage is expected to rise dramatically by the end of the decade. Production of steel from recycled material requires less energy, generates less pollution than output from virgin material. A s a result of the presence of impurities, there will ultimately be a degradation in the quality of recycled steel. However few of the uses of steel in buildings require high-grade material.  Aluminum  31  « The resource issues relating to aluminum are much the same as those for steel. Bauxite the raw material for aluminum is an extremely abundant material in the earths crust. The percentage of material manufactured from recycled product, at approximately 30%, is even higher than that of steel. Given the economic incentives that exist in terms of energy savings (recycling aluminum uses less than 1 0 % of the energy required for production from ore) the percentage seems likely to rise.  Plastics •  Plastics, adhesives, and other petrochemical materials are derived from oil or natural gas. A s such they are subject to the same limitations as fossil fuels and long term scarcity is clearly an issue, particularly if fossil fuels continue to be used for energy uses. However the future scenario described envisions energy generation from fossil fuels being phased out prior to resources being depleted, oil and natural gas would thus become available for use as feedstocks in petrochemical production.  Glass and ceramics •  Again the raw materials are ubiquitous, and there would appear to be limited possibility of resource depletion on any time scale of concern to the present study. There may indeed be potential for glass and ceramics to replace other materials such as metals and plastics.  The preceding analysis of building materials deals only with the issue of materials scarcity and the possibility of increases in the embodied energy which might result. It would appear that this outcome is unlikely and need not be considered further in the analysis of the study building. W h e n other environmental impacts of materials acquisition, processing and manufacture are considered however, a less optimistic viewpoint emerges. The limiting factor to the continued use of many of these materials may not be the magnitude of existing reserves but rather the environmental consequences of attempting to exploit even a portion of those reserves. The  32  C0  2  emissions associated with the manufacture of concrete for example represent 5 % of total  global carbon dioxide emissions. Similarly the environmental impacts of the vast hydro electric plants required to manufacture aluminum are far more likely than resource depletion to place limits on future rates of production and use of these materials.  3.2.3.3 Improvements in Technology Continual technological improvement and innovation are a characteristic of industrial societies. Advances in technology are frequently associated with improvements in the efficiency of energy or resource use, doing more with less, or with providing new more efficient means to provide for human needs. Improvements in technological efficiency will effect buildings both directly and indirectly. Direct impacts: All building involves the application of technology to serve human needs. The level of technology involved varies from building to building and within the different parts and systems of buildings. Building environmental control systems for example represent sophisticated "high" technology, while wood stud framing involves relatively simple technology. The efficiency of the application of both technologies has improved and potentially can continue to improve, although not necessarily at the same rate or to the same extent, over the course of time. Technological advances are also likely to provide completely new materials, components and construction techniques (ceramics, prefabrication, etc.). However, it is important not to over estimate the impacts or significance of this type of innovation. During the last 30 considerable changes in technologies such as electronics, computers, and communications systems have occured which have had a direct impact on buildings. S u c h advances however have occurred  33  only in certain fields; most building systems, structure, interior and exterior enclosure have altered remarkably little over this time period. Indirect impacts on buildings In addition to the improvements resulting from doing more with less material (advanced framing techniques, electronic controls etc.) the efficiency at which energy is used by mechanical and electrical systems will also improve as a result of technological improvements. Indirectly improvements in efficiency occur across all sectors of the economy. With the general trend in global energy efficiency, the energy required to produce unit quantities of materials and products, including those destined for the construction industry, is decreasing. Thus in addition to the direct impact of improved efficiency on buildings, in terms of doing more with less energy and material, the efficiency of the materials themselves is also increasing and this improvement is reflected in the general reduction in the embodied energy of materials and components over time. For the purposes of analysis of the study building the rate of improvement in the operating efficiency of building systems and in materials embodied energy will be assumed to be 1 % per year. In summary, general technological improvement has the following impacts on buildings: •  The efficiency of materials use increases (e.g., advanced framing techniques)  •  The efficiency of energy use increases (more efficient mechanical and electrical systems)  « The energy efficiency of the materials and components that make up the building increases  3 . 3 MATERIAL CHANGES IN OFFICE BUILDINGS Additions to the embodied energy of buildings during the course of their life-spans occur as a result of material additions to the various building systems previously described. (Major changes also occur to the contents of buildings, furniture, appliances etc. Although in  34 embodied energy terms the impact of these changes may be significant, they are peripheral to the construction industry and are beyond the scope of this study.) There are three fundamental mechanisms or reasons for additions to buildings. •  Replacement of existing materials or components This involves the addition of replacement materials and components. The new material may or may not be the same as the existing material but it will be performing the same function. In the case of replacement, as new material is added a similar quantity of existing material is typically removed.  •  Maintenance of existing materials or components In embodied energy terms maintenance may be considered to be replacement of a portion of the material or component in question. Replacement and maintenance therefore only differ in the amount of the material involved. The purpose of maintenance is typically to prevent premature functional obsolescence, while replacement may result for many other reasons.  •  The addition of new materials or components.  3.3.1 Reasons for Change « Functional and economic obsolescence The product or material in question may no longer perform as intended. Building materials or components may fail completely, be too expensive to repair, or their level of performance may have fallen to unacceptable levels. Elements and components may be replaced for other reasons before they become functionally obsolete. Materials or components may still be functioning as intended but the cost of maintaining them exceeds the cost of replacement with new elements, this may be termed economic obsolescence  35 •  Technological obsolescence  New technology may make existing systems obsolete as a result of increased performance expectations on the part of building owners and users. It may be possible to particular building systems and components which are likely to become  anticipate  technologically  obsolete. This type of change may be connected to economic obsolescence, in that incentives to replace components  may be driven by the potential  cost savings of more  efficient  technology, e.g., electrical and communications systems, mechanical systems •  Aesthetic obsolescence  Changes required in the appearance of a building or parts of a building due to changes in fashion. Changes are typically made for economic reasons associated with marketability. This type of change is most important in the case of commercial buildings, e.g., recladding of exterior facades, repainting, changing interior finishes. •  Social / cultural change  Changes  in  social attitudes  may  directly  affect  buildings;  increased expectations  accessibility has resulted in revised layouts and additional facilities in commercial  for and  institutional buildings. Another example is the change from partitioned offices to open-plan layouts. •  Regulatory change  Changes necessitated by new building standards. These usually only apply if the building is being upgraded. C h a n g e s to one part of the building may mean that certain aspects of whole building have to be upgraded, e.g., access for persons with disabilities, fire alarms, sprinklers •  Change of use  Changes in use may result from a major change in function of the building, a completely new activity  replacing existing  use for  example  a warehouse  building  being  converted  to  36 apartments. Alternatively there may be a change in use or activity with no change in major function of building. Changes in the nature of the activities that take place within that type of building may result in modifications, e.g., changes in office communication technology may make mail rooms unnecessary. Changes to any material or element for any of the above reasons may also indirectly result in changes to other materials or components. These changes may be desirable and a result of a conscious decision or may be unavoidable: a) Because it is physically impossible to change the element or material in question without damaging or rendering ineffective other associated materials, e.g., replacement of roof insulation board when membrane is replaced. b) For economic reasons, it may be less costly to replace materials or elements prematurely while other changes are made rather than wait for the full life-span of these materials to expire.  3.3.2 Changes in Office Accommodation Requirements In addition to the general environmental, social and economic trends that will influence future changes in buildings, there will be changing programmatic requirements specific to particular types of buildings. Much of the technical literature on office development stresses the dramatic changes that have occurred over the course of the last 30 years in office design, and inferred attitudinal  change.  Cellular  office  layouts  gave  way  to  open-plan  "burolandschaft"  arrangements, which are now being replaced in some recent European office buildings with smaller cellular group work spaces. Increasing service space requirements to accommodate air-conditioning ducts and electrical cabling have resulted in heightened floor-to-floor dimensions. Floor plan arrangements that relied on natural lighting have been replaced with deep plan electrically lit arrangements. New  37  forms are evolving to once again provide natural light to all workspaces. Within the financial services sector there are new requirements for larger, deep plan trading floors. However many of these changes relate either to internal arrangements of space or deal with "high-end" corporate office accommodation. More surprising perhaps, is how little office accommodation and office buildings have changed in their basic forms. Most office activities continue to involve an employee sitting on a chair in front of a desk. The equipment on the desk has changed dramatically but the basic seating and work area arrangement is governed by anthropomorphic and ergonomic requirements which do not change. MacCormac has discussed the similarities between 15th century Italian office buildings and contemporary examples. (MacCormac 1992)  Possible future trends and issues in office buildings include: •  More flexibility in terms of the range of spaces available. Smaller more flexible spaces may be required for downsizing organizations.  •  Decreases in the energy loads on internal environmental control systems arrising from information technology systems as equipment becomes more energy efficient and emits less heat. (LCD screens, smaller more powerful workstations using central databases)  •  Emphasis on providing daylighting to all work areas.  •  Preference for natural ventilation and passive environmental control and individual control rather than conventional air conditioning. Code regulation of indoor air quality.  •  Changes in floor to floor height; to accommodate raised floors, or as a result of a move away from fully air-conditioned buildings.  •  Replacement of copper wiring with fibreoptics.  38 •  Structured cabling systems (provided throughout the building with regular outlets), single channel for voice, data, fax, video and B M S (ISDN - Integrated Digital Service Network)  •  Wireless communication and control systems  •  Requirement for more sub-equipment rooms  3.3.3 Workspace In Chapter 2 the idea of measuring the efficiency of office buildings in terms of area per person was introduced. To include this concept in a life cycle analysis it is necessary to examine how the rate of accommodation may change in the future. In contrast to the trend in residential accommodation the area per person in commercial construction has dropped dramatically since the beginning of this century. Commercial buildings in the first two decades of the century provided approximately 140 m per occupant, by the early 1980s this had decreased 2  to 77 m . A modest increase to 82 m per worker was recorded during the latter part of the 2  2  decade. It should be noted that this study covers all commercial buildings and not just offices; however as offices make up a significant percentage of total commercial building, the broad trend is likely to be similar. It would appear that in recent years the trend towards smaller workstations has slowed and perhaps even reversed.  3.4 ALTERNATIVE FUTURE SCENARIOS FOR STUDY BUILDING  'scenarios are stories about the way the world might turn out tomorrow, stories that can help us recognize and adapt to changing aspects of our present environment,  The purpose of  Scenarios is to change your view of reality - to match it up more closely with reality as it is, and reality as it is going to be."  39 Peter Schwartz (The Art of the Long View 1991) Three possible future Scenarios for the study building are envisioned, in two of these the building continues as an office building while in the third a change of use is proposed. The first two scenarios are in part based on Brand's definitions of "High road" and "Low road" buildings (Brand  1994). The Scenarios recognize that the  broad category  of "office  buildings"  encompasses a wide variety and quality of accommodation. At the high end of the scale are "prestigious" Downtown offices offering a high degree of comfort, services and finishes in buildings that are technologically and aesthetically contemporary. At the opposite end of the scale are low rent offices, often  in older buildings offering  lesser levels of services,  environmental control and finishes at lower rents. While  the  study  building  does  not  represent  the  most  prestigious  type  of  office  accommodation, it is, in the context of the range of office accommodation available at the time of construction, intended to be of an above average standard. However it is suggested that although at any point in time a building may offer a particular level of office accommodation, during the course of its life the quality of that accommodation may change in both absolute and relative terms. It is unusual for buildings to move up on the scale of accommodation to provide a level of service and comfort greater than that provided initially. In part this is due to the increasing level of service found in newer office buildings. The most common trend is for buildings in any specific location to gradually move down the scale relative to locally available office accommodation. The rate of this decline will vary and is dependent on many factors (location, initial character, the aesthetic preferences of owners and users, technological obsolescence etc.). A building's decline on the scale may be slowed, or even temporarily reversed, by investing in renovation and up-dating, never-the-less the general trend is downward.  40  Innovations are typically introduced at the high end of the accommodation spectrum and may or may not  ultimately  be adopted  in all office  buildings. With  new office  buildings,  accommodating change and designing for anticipated future change is relatively easy. Difficulty arises when existing office buildings have to be upgraded to accommodate the kind of changes not foreseen when the original building was designed. There are a number of possible outcomes if a particular office building cannot physically be adapted to provide the desired new level of service. The building may be treated as obsolete and may, if located on a valuable site, be demolished to make way for new updated accommodation. Alternatively the building may be retained, with or without a lesser level of upgrading, to provide a lower level of accommodation. In this case its relative position on the scale of office accommodation is lowered. The extent and rate of change both in relative and absolute terms may however have a significant impact on its recurring embodied energy over the course of its life -span. In order to explore these impacts, the following Scenarios offering different alternatives are proposed.  3.4.1 Scenario 1 The building is designed and constructed to offer a particular level of accommodation and service, relative to other office buildings it can be seen as occupying a position on a scale measuring quality of accommodation. During the course of its life it slowly moves down this scale. However this downward movement is periodically halted and even temporarily reversed by renovation and upgrading and it maintains its relative position on the scale of office accommodation. For this reason the building attracts clients prepared to pay higher rents. S u c h clients are more likely to have money to spend on tenant improvements and are more likely to require that internal arrangements be altered to suit their specific requirements at each change in occupancy. Thus each time there is a change in occupancy there are likely to be  41  extensive interior changes. Table 3.1 below gives details of the frequency and extent of the major changes envisioned in this scenario. Table 3.1 S c e n a r i o 1 - Major C h a n g e s during Building Life s p a n Column 1 indicates the type of change, column 2 the building elements and systems changed. The percentage of these elements or systems involved in each change of this type is given in column 3 and Change Tenant improvements (a) Tenant improvements (b) C o m m o n areas upgrade (c) Envelope upgrade - roof Envelope upgrade - walls and glazing Systems upgrade - electrical Systems upgrade - electrical Lighting Systems upgrade - H V A C Systems upgrade - Plumbing  Elements involved Partitions, doors, ceilings, finishes Ducting, sprinklers, electrical, lighting Floor, wall and ceiling finishes Membrane, insulation, air barrier, flashings Wall cladding, insulation, glazing (frames and glass) Distribution, communications, B M S Lighting, fixtures, ballasts H V A C plant  % involved  Frequency  %  years  50 10 100 100  5 5 10 20  100  30  50 50  15 20  90 50  20 30  (a) Architectural components of tenant improvements (b) Mechanical and electrical components of tenant improvements (c) Primarily building lobby  In addition to the major changes listed in Table 3.1 almost all building elements with the exception of the structural elements are also periodically replaced for reasons of functional obsolescence. In these cases 1 0 0 % of the material is replaced. In addition to complete replacement, material is also added to the building during regular maintenance activities. These additions are also accounted for.  3.4.2 Scenario 2 The building is designed and constructed to provide the same level of accommodation as in Scenario 1, however its downward movement on the scale of office accommodation is not halted by major renovation or upgrading. Maintenance and renovation are provided at levels intended to maintain basic building functions only. The building thus does not maintain its  42  relative position on the scale in terms of level of accommodation provided and the rents realized drop accordingly. Tenants paying lower rent rates are less likely to have money available for expensive tenant improvements and are more likely to adapt themselves to suit the existing layout and services than to change the environment to suit their particular circumstances. W h e n changes are made they will involve fewer materials and elements and be less frequent than in Scenario 1. Changes will typically occur only for reasons of functional obsolescence. The changes associated with replacement and maintenance of individual components (as opposed to complete subsystems), associated as they are with functional obsolescence, will be broadly similar to those in Scenario 1. Table 3.2 S c e n a r i o 2 - Major C h a n g e s during Building Life s p a n Column 1 indicates the type of change, column 2 the building elements and systems changed. The percentage of these elements or systems involved in each change of this type is given in column 3 and Change Tenant improvements (a) Tenant improvements (b) C o m m o n areas upgrade (c) Envelope upgrade - roof Envelope upgrade - walls and glazing Systems upgrade - electrical Systems upgrade - electrical Lighting Systems upgrade - H V A C Systems upgrade - Plumbing  Elements involved  % involved  Frequency  %  years  Partitions, doors, ceilings, finishes Ducting, sprinklers, electrical, lighting Floor, wall and ceiling finishes Membrane, insulation, air barrier, flashings Wall cladding, insulation, glazing (frames and glass)  25 10 75 100  10 10 20 30  100  50  Distribution, communications, B M S Lighting, fixtures, ballasts  50 50  25 25  H V A C plant  90 50  30 50  (a) Architectural components o 'tenant improvements (b) Mechanical and electrical components of tenant improvements (c) Primarily building lobby  3.4.3 Scenario 3 (Major change in use of building from commercial to residential) The third scenario is based on a major change in use of the building from commercial to residential occupancy. There are a number of reasons to suggest that such changes may become more common.  Rapid technological advances in Information Technology  (IT)  43  requirements and new space planning arrangements may result in the marginalization of many existing office buildings. The capital investment in existing office building stock is enormous, and it may not be possible to write off such investment (through demolition) over the increasingly short time periods involved in changing IT requirements. Changes in work patterns are beginning to blur the distinctions between activities that traditionally take place in homes and offices, increasing numbers of people are now working from home and, the demand for residential accommodation may outstrip that for offices. Examples of similar transformations from warehouse and industrial building use to apartments have become common place in Vancouver in recent years. The commercial success of these projects indicates a market for the high density Downtown residential accommodation. Changes from office to residential use are not yet as common although examples do exist in the city Because of greater similarities between office and apartment buildings conversions will be much easier to accommodate. Table 3.3 Scenario 3 - Major Changes during last 50 years of Building Life span (First 50 years as per Scenario 2)  Column 1 indicates the type of change, column 2 the building elements and systems changed. The percentage of these elements or systems involved in each change of this type is given in column 3 and the frequency of this type of change is listed in column 4-  Change  Elements involved  % involved %  Frequency years  Tenant improvements (a) Tenant improvements (b) C o m m o n areas upgrade (c) Envelope upgrade - roof  Partitions, doors, ceilings, finishes Ducting, sprinklers, electrical, lighting Floor, wall and ceiling finishes  25 10 75 100  10 10 20 30  40  50  25 25  30 30  90 50  30 50  Envelope upgrade - walls and glazing Systems upgrade - electrical Systems upgrade - electrical Lighting Systems upgrade - H V A C Systems upgrade - Plumbing  Membrane, insulation, air barrier, flashings Wall cladding, insulation, glazing (frames and glass) Distribution, communications, B M S Lighting, fixtures, ballasts H V A C plant  (a) Architectural components of tenant improvements (b) Mechanical and electrical components of tenant improvements (c) Primarily building lobby  44  Scenario 3 envisions the entire building being converted to residential accommodation after a 50 year period as a office building. The office portion of the buildings life span is identical to the first 50 years of the Scenario 2 building. The large uninterrupted open plan of office floors and 22 metre building depth are ideally suited to accommodate standard apartments layouts. A s residential structural loads are typically lower than those in commercial buildings no alterations to the structural system are required. Nor will the 7.5 metre structural grid impose any limitations on the possible layouts. The floor to floor dimension of 3.6m will readily allow additional building service systems to be provided. The converted building is designed to provide a total of 74 apartments, 64 one-bedroom units at 7 5 m and 10 larger two-bedroom units at 1 1 0 m . 2  2  S e e Drawing A6 (Appendix 2) showing a typical floor layout and plans of both units.  45  Chapter 4 BNSTIAL EMBODIED ENERGY  4.1 INTRODUCTION "Energy intensity refers to the energy used in an economy  in the production  of goods  and  sen/ices" (Proops). Embodied energy is the total energy requirement of all activities necessary to produce a material, product or service, from raw materials acquisition to delivery of the product to the consumer. Two types of energy are involved in each separate activity, or stage, of the process of producing goods and services, "direct" energy and "indirect" or "embodied" energy. Both types of energy are combined to provide an embodied energy output which may in turn become an indirect energy input to another stage of a particular process.  Direct Energy In + Embodied Energy In = Embodied Energy Out. (Proops)  4.2 EMBODIED ENERGY IN CONSTRUCTION Embodied energy in the context of the construction industry is the energy required to fabricate both the building and the materials and components from which it is constructed. Energy is needed to extract or acquire the raw materials from which building materials are produced. Further energy is required to transport raw materials and for additional processing and manufacturing. The number of steps and quantity of energy involved in the process of transforming raw material into finished product will depend on the nature of the material in question. For example, the sequence involved in acquiring sand for use in construction is relatively simple, the material is typically transported over short distances, and consequently  46  requires little energy; 0.05 MJ/kg. The manufacturing of aluminum extrusions on the other hand entails numerous steps, the raw material is bulky and is typically transported long distances, the refining and manufacturing processes also require large amounts of energy. Aluminum at 274 MJ/kg is thus a much more energy intensive material. In addition to the energy required to fabricate basic building materials and components, energy is needed to transport the finished products to the  building site and to install them  construction. In the context of the construction industry:. •  Direct energy is the energy required to construct the building. It is energy that is primarily expended at the construction site but also includes the final transportation energy of materials and components from their place of manufacture to the building site. Direct embodied energy, also known as "construction energy", represents fuel inputs and typically accounts for between 7 and 10 percent of the total initial embodied energy of a building. (Stein 1976, Salokangas 1990, Cole 1994)  •  Indirect energy is the energy required to fabricate the materials and components from which the building is constructed. It includes the energy required to extract, process and transport raw materials, the energy required for manufacture of materials or components and finally transportation energy for all stages of this process.  4.2.1 Terminology A s previously described the embodied energy of the building is the s u m of the direct energy inputs and indirect, or embodied energy, inputs. (Proops) In energy analysis "direct energy" refers strictly to fuels used by a particular industrial sector. In the case of the construction industry direct energy, represents the fuel inputs required to  47  transport materials and construction workers and to assemble materials and components to create complete buildings. Strictly speaking it is therefore not appropriate to speak of the embodied energy of the building,  or of building systems, unless the direct energy component  (construction energy) has been included in the calculations. W h e n the term embodied energy is used in the context of the study building it may be taken, unless noted otherwise, to include both direct and indirect energy.. It is appropriate to use the term embodied energy in the context of building materials and products as both the direct and indirect components of the embodied energy of each materials have been included. Direct energy in this case represents the fuel inputs to the manufacturing stage of the material or product rather than the construction energy required to assemble the material. A s raw material is acquired, processed, and manufactured, direct energy, in the form of fuel energy, is input at each stage and combined with the embodied energy output from the previous stage to provide the embodied energy input to the next stage. Figure 4.1 graphically represents the various inputs involved in each stage of the manufacturing process of a typical building material. The direct energy input for each stage of the process also includes the energy required to transport the indirect energy inputs to that stage. It should be noted that the term embodied energy does not imply that the energy is physically present in the material in question rather that this energy has been consumed in the various processes involved in manufacture. (Proops)  48  Figure 4.1 Conceptual diagram of the manufacturing process of a typical building material I Direct energy i n p u t " ) - ^ | Direct energy input  Material extraction  A  Output  )  Direct energy input  Material processing  Product manufacture  Input  Input  Output  Direct energy input  Construction industry  Output  Input Output  Indirect energy (embodied energy)  |  |  Indirect energy (embodied energy)  j  |  Indirect energy (embodied energy) BUILDING (embodied energy)  4.2.2 Control over Embodied Energy in the Construction Industry The boundaries that establish the extent and influence of the construction industry are difficult to define. At its broadest the industry has been seen to include " the mining and lumbering  sectors as well as the steel mills, the sawmills, the aluminum smelters, the cement factories and the brick kilns." (Stein - Analysis and Reduction of Energy in the Building Industry). While the largest part of the output of brick kilns and cement factories is clearly destined for use in buildings, the same is not necessarily true of the products of aluminum smelters and steel mills. Substantial quantities, perhaps the majority, of the materials produced are ultimately used in non-construction sectors of the economy. This broad definition would thus include within the construction industry all of the steps shown in Figure 4.1. The construction industry may also be more narrowly defined to include only those activities that occur on building sites and that relate to the construction or assembly of buildings. Defined in this way the construction industry includes only the last stage shown in Figure 4.1. These two definitions of the scope of the construction industry can be related to the direct and indirect components of the embodied energy of buildings. The first definition includes both  49 direct and indirect energy inputs to construction while the second is concerned only with direct t  energy. Also important in any portrayal of the construction industry are the individuals involved and the relative control they exert over the industry. The traditional decision makers in construction, contractors, architects, engineers and clients have direct control only over the activities that occur on the building site or in certain off-site fabrication facilities. This represents influence over, and the ability to control, the direct embodied energy component of buildings only. Indirectly the choices architects, engineers and contractors make may over the long term result in changes in the industries supplying building materials, although far more important in this regard is the influence of public opinion. Control over the indirect component of construction industry embodied energy rests with decision makers in non-construction sectors of the economy. A s indirect embodied energy is by far the largest portion of the total we may anticipate that the greatest reductions will be achieved in this area and will result from decisions made in the materials acquisition, manufacturing and transportation industries.  4.2.3 Forms of Embodied Energy Embodied energy is incorporated into a building over the course of its life span in two forms or stages: •  Initial embodied energy: The embodied energy required to construct a new building; includes both the direct and indirect components described above but is confined to materials and components incorporated during the single relatively short construction phase of building.  •  Recurring embodied energy: Includes all of the materials and components incorporated into the building during the course of its life. This form of embodied energy represents the  50  embodied energy expended in building maintenance, repair and replacement. Recurring energy is thus expended at intervals during a buildings operational life.  4.3 ENERGY INTENSITY The "energy intensity", "energy coefficient" or "unit factor" of a material is the energy required to produce a particular quantity of that material. Depending on the nature of the material the units of measurement will vary. It is common to quote energy intensities for bulk materials such as concrete and sand in terms of energy per cubic metre. Other energy intensities are defined in terms of energy per unit building component, e.g., energy per brick, or energy per unit measurement of material, e.g., energy per square metre of gypsum board. The most commonly used method however, is to define the energy intensity of a material or component as energy per unit mass, and is the convention followed in the present study. Although some of the sources used for this study report intensities in other units they are converted to energy per unit mass, MJ/kg, for consistency. This method also facilitates calculation of the mass of the overall building and building systems, data required for the derivation of demolition and construction energy. There is no "correct" or absolute energy intensity for any material or component. (Baird and C h a n 1983) Energy intensities for the same building material will differ as a result of three major sets of variables. •  Selection of appropriate system boundaries used in their derivation  •  Variations due to locational factors, different manufacturing processes and efficiencies  •  Date of data collection  4.3.1 System Boundaries In attempting to derive energy intensities for materials decisions must be made establishing appropriate system boundaries for the analysis process. Depending on where the boundaries  51 are located and on the analysis methods used certain elements may be included or excluded and widely different results obtained. (Optimize 1991) Energy analysis may be taken to various levels of detail, e.g. energy used by mining equipment used to acquire raw materials is almost always included in analysis to derive energy intensities. Additionally the analysis may proceed to a further level of detail and include the energy required to manufacture this equipment or even the energy needed to make the machines that make the mining equipment. These difficulties have been recognized and the International Federation of Institutes for Advanced Studies (IFIAS) has developed a set of standards for energy analysis. The standards have been adopted by many researchers working in this field including most of those referenced as sources for this study. (Cole & Rousseau 1992, Optimize 1991, Baird & Chan 1983) Although the IFIAS has defined four levels of system boundaries; most analyses of embodied energy are confined to the first two levels, however together these two levels capture approximately 9 0 % of the energy embodied in a particular material or component. (Cole & Rousseau 1992, Optimize 1991)  4.3.2 Location and Efficiency Factors Energy intensity is also influenced by the particular circumstances pertaining to the place and time of acquisition, processing and manufacture of a material. The distances over which raw material must be transported, the efficiency and age of processing and manufacturing plants, the level of technological sophistication applied and the distances of production facilities from markets can all significantly affect the value of the embodied energy of a material. Steel produced in the United States requires approximately 25 MJ/kg, however in Italy and Spain the comparable figure is 18 MJ/kg. The difference is primarily due to the fact that the European countries derive a large portion of their raw material from scrap, with consequent reduction in energy required for raw material acquisition and refining. In addition the high percentage of  52  scrap material allows the use of more efficient technology in the form of electric arc and recycling furnaces. (Vital Signs 1992) In Canada the energy intensity of steel reinforcing bars produced in standard integrated plant steel mills is 36 MJ/kg while more efficient mini-mills using electric arc furnaces require only 15 MJ/kg. (Forintek 1 and 2). The energy efficiency of many of the processes involved in materials production have improved over time as newer and more advanced technology have been developed and applied by industry. Thus over the course of time the energy intensity of materials decreases as newer and more efficient production plants replace older facilities. A s a results of improvements in technology the energy intensity of U.S. steel has dropped from 52.8 MJ/kg in 1976 to 25 MJ/kg in 1992. (Stein 1976, Vital Signs 1992) At any given time the energy intensity of the same material produced at an older plant will be higher than that produced by a facility using state of the art technology. Different fuel types used in manufacturing processes can also result in differences in embodied energy of the same material. Large amounts of electricity are required for the production of aluminum, this electricity can come from numerous sources, hydro, thermal (generated from fossil fuels) or nuclear. Because of the relative inefficiency of the conversion process of thermally generated electricity aluminum produced using these sources will have a higher embodied energy than that produced with hydro electricity.  4.4 ENERGY ANALYSIS METHODS In calculating the energy intensity and embodied energy of materials two primary methods of analysis are employed; Input-output analysis and Process analysis. Almost all of the recent studies of embodied energy of construction materials employ one or other or a combination of these two procedures. Several other analysis techniques have also been identified such as,  53 Hybrid analysis (Kohler), Statistical analysis and Eco-energetics (Optimize 1991) but they have not been commonly used in the building science field.  4.4.1 Input - Output analysis Probably the most commonly employed method, it is based on the use of input-output tables. These tables are compiled from national surveys of transactions between all sectors of the economy during the course of a particular year. A n economic matrix is developed which summarizes the inputs to each individual industry from all other industries within the economy and the outputs from that industry to each of the other industries. Input-output tables quantify the inputs of all of the commodities required to produce a given quantity of a final product. Monetary values are used to measure the inputs and outputs of commodities in the matrix. These units are converted into energy values using energy tariffs based on energy statistics and the nature of energy use within the various sectors of the economy. (Peet 1993) The surveys used to produce input-output tables are carried out in Canada by the Structural Analysis division of Statistics Canada and are produced every 5 years. The matrix table produced for the  Canadian economy  lists 130  industrial  sectors and  602  individual  commodities. Of these 602 commodities, 58 are products or materials that are commonly used by the construction industry (Optimize). Advantages •  The input - output analysis method is comprehensive and offers an all-embracing way of determining total energy requirements of a particular industry. It captures both direct and indirect energy. It is often the only method available that can include indirect energy.  Disadvantages  54 •  Input - output analysis does not allow disaggregation of data for particular commodities within an industry. A single figure may cover two or more different and distinctive products produced by a particular industrial sector for which individual data is required. A high degree of disaggregation, will increase the level of inaccuracy when an energy intensity is applied to a particular product, (e.g. - steel and stainless steel)  •  A n industry which produces a diverse range of outputs is classified according to its principal product. If secondary and tertiary products have different embodied energies significant inaccuracies in published figures can result.  « A s data is collected and combined every 5 years it is possible that published figures may be out of date. Peet suggests however, that this is not necessarily a disadvantage as major structural changes in an economy take place slowly and as a result published data is usually satisfactory for at least 10 years (Peet 1993). o Figures for a particular commodity are averaged across a whole industrial sector. Variations between different production  plants within a particular  sector may be greater  than  differences between material alternatives. (Cole, ed. 1992)  4.4.2 Process Analysis Process analysis involves an investigation of the production process of a particular material or component. The inputs to the various processes involved in producing a particular commodity are analyzed and quantified in energy terms and then compared to the output of products of the overall process. Process analysis is a useful and accurate tool for calculating direct energy inputs. However if indirect energy has also to be determined the method becomes increasingly complicated as various energy and material inputs have to be traced back through a complex web involving many different economic sectors. (Peet 1993)  55 Advantages •  The principal advantage of process analysis is that it can provide detailed and extremely precise information on the energy intensities of particular materials or products.  Disadvantages » The main difficulty arises in determining how representative the study process is of the industry as a whole. While input - output analysis captures and averages data for a entire industry, process analysis may be carried out on a single manufacturing plant or small number of plants which may not be representative of the total industry. Figures for energy intensity of a material may be based on a "state-of-the-art",  rather than an average  representative, industrial plant. » Appropriate data on which to carry out process analysis may not be readily available. S u c h data may be considered by the industry or processing plant in question to be confidential. Data is typically collected by industry representatives, and as commercial interests are involved, may not always be entirely objective. •  Because process analysis is based on information gathered from individual manufacturing plants and industries it may not be consistent in terms of methods and dates of collection, system boundaries etc. In these cases accurate and meaningful comparisons of materials or products are often difficult to make.  4.5 PREVIOUS STUDIES OF EMBODIED ENERGY Many studies of the energy intensity of building materials have been carried out in different countries over the last 20 years. Over this time period a general consensus has developed concerning  definitions  of energy  intensity  and  embodied  energy,  and  methodologies  appropriate for their derivation. A considerable body of relatively consistent data now exists on  56  the embodied energy of a broad range of building materials and components. The most significant of these previous studies have been reviewed and analysed in detail. Details of energy intensities, analysis methods, system boundaries and age of data has been collated and compared. Table 4.1 below lists the main sources used as references in the current study. Further information on each of these studies may be found in Appendix 3. Table 4.1 Major previous studies of energy intensity of building materials and embodied energy of buildings. Study Stein et. al. Baird and Chan Buchanan and Honey Environmental Research Group U B C Optimize Danish Building Research Institute Forintek / E R G U B C Edwards et. al. j Baird et al.  Date  Source  1976 (1967) 1983 1994 1991, 1992 1991 1994 1993 1994 1994  United States New Zealand New Zealand Canada Canada Denmark Canada Australia New Zealand  Dates of the data used in the studies, where reported, are given in brackets after the date of the study itself  4.5.1 Energy Intensities It is beyond the scope of the present study to attempt to derive current energy intensity data for building materials specific to British Columbia. However information already exists on the embodied energy of many common building materials. The study building described in Chapter 2, contains 102 distinct materials or building components for which  appropriate  energy intensities had to be selected. None of the previous studies were able to provide data for each of these items, indeed many of the them were not included in any of the studies. Certain common materials such as concrete, steel and wood appear in numerous studies, but for reasons discussed in earlier sections may have different values. Figures for certain other materials are available from several sources while each study typically also lists a number of unique items. The following protocols were used to assign values to each material and component in the study building.  57 » Energy intensity figures based on current Canadian data where used directly. For example the unit factors for steel, concrete and wood provided by the Forintek study (1993) are used with no changes. •  Next, figures from less recent Canadian sources such as the Optimize and E R G studies were reviewed and in most cases the energy intensities reported were also used directly. Figures in these studies for materials that had already been assigned values based on the Forintek study data were compared with those assigned values for verification.  These steps provided embodied energy figures for most of the materials in the study building. To determine the embodied energy of the many manufactured components in the building the mass of each material in the component was determined and multiplied by the energy intensity of that material and also by a factor to account for the level of additional manufacturing require to fabricate the finished component. Table 4.2 below lists the energy intensities given in a number of previous studies for the major materials in the building and compares them with the intensities selected for the current study.  58  Table 4.2 Comparison of chosen energy intensities of major materials in study building with those used in previous studies Material  Date of study Steel (structural sections) Concrete (C.I.P.) Plastics (Polystyrene) Aluminum Glass Brick Gypsum board Copper Wood Sand  Previous study, energy intensity MJ / Kg. 1.  2.  3.  4.  5.  6.  7.  For.  C&R  Opt.  B&H  Stein  DBRI*  Kohler  1993  1991  1991  1994  1976  15.4(a)  25.7  20.78  59  52.8  32  27.7  .75 n.a.  1.2  0.54  1.66  1.49  .76  0.91  133  188.60  96  177.7  106.74  122.76  n.a.  274(b)  n.a.  145  214.4  235  261  n.a.  10.2  21.55  31.5  34.1  18.6  21.6  n.a.  4.9  2.14  6.9  7.41  2.3  3.06  n.a.  7.4  4.48  9.76  8.12  8.64  4.74  n.a.  n.a.  29.46  45.9  109  70.2  46.8  5.8  3.12  7.38  4.65  7.5  5.18  5.04  n.a.  n.a.  0.051  0.04  n.a.  .001  .14  This study 1995 28 0.75(c) 105 274 18.75 2.5 9.76 50 5.8 0.05  1. Forintek, 2. Cole and Rousseau, 3. Optimize, 4. Buchanan and Honey, 5. Stein et. al., 6. Danish Building Research Institute, 7. Kohler. * Combination of two sources 1. Dinesen and Traberg-Borup 2. Krogh and Hansen (a) Figure is for structural steel produced in energy efficient 'mini-mills', a previously published figure for structural steel was 41.6 M J / kg (original Forintek study - steel) (b) Figure is for anodized aluminum, unfinished aluminum = 236 M J / kg (c) Figure is for 25 M P a concrete and is interpolated from the Forintek study figures for 20 and 30 M P a concrete.  4.5.2 Embodied Energy of Office Buildings In addition to reporting energy intensities for various building materials and components many of the previous studies of embodied energy also calculate embodied energy figures for complete buildings. Figures typically only account for initial embodied energy and are given in units of Gigajoules per square foot or per square metre (GJ/m ). Table 4.3 below provides 2  figures for office buildings from a number of previous studies. A wide range of values are recorded from Stein's figure of 18.6 G J / m to 3.35 G J / m for a wood framed office building in 2  New Zealand.  2  59  Table 4.3 Comparison of initial embodied energy studies of office buildings Study  Building type  Date of study  Emb. energy GJ/m  Relative to this study  1994  5.6  139%  4620  New Zealand BC  1994  4.93(a)  122%  2400 8568 3253 Average 3500  New Zealand UK US Japan  1992  118% 160%  1991 1976 1993  4.75 6.46 1.34 (b) 18.60 11.18  3150  New Zealand  1994  1 95(c)  8015  BC  1994/5  4.03  Building size m  Location  2  Buchanan and Honey (1) Forintek  3-6 storey concrete framed 3 storey concrete framed  Buchanan and Honey (2) Gardiner and Theobald Stein, et al., Oka, Suzuki & Konnya Baird, Treleaven & Storey  This study  Concrete framed 8 storey concrete framed 5 storey concrete framed  5 storey concrete framed  Average  2  462% 277%  100%  (a) The building analyzed in the Forintek study is a three storey version of the 5 storey building used in this study (b) Structure only, the structure only figure for the study building is 1.26 G J / m (c) Structure only - note the energy intensity figures used were 3160 M J / m for concrete (this study 1768 MJ/m3) and 12 MJ/kg for rebar (this study 25 MJ/kg) Note also the new Zealand building uses piled foundations. 2  3  A number of factors may account for the differences observed. •  The date of the survey or of the data used in the calculations may be significant. There has been a general decrease in the energy intensities of materials as a result of an improvement in the energy efficiency of manufacturing industry and other economic sectors. Statistics Canada has documented a decrease of approximately 1 % per year in the energy intensities of materials over the last 20 years.  •  Different manufacturing procedures may be used in the various countries from which data is available.  •  Changes in building technology over the course of time, for example the trend towards lighter construction.  o Differences in embodied energy per unit of floor area may change significantly with changes in size of building. The test building for this study has an identical floor plate to the building  60  analyzed in the Forintek study, the only difference being in the number of storeys; the Forintek building has 3 floors above grade with one level of underground parking while the study building is a 5 storey building also with one below-grade floor. Thus the difference in the embodied energy per square metre is a result of the differences between the ratios of floor area to exterior envelope, building services, sitework etc. In discussing the problems associated with comparing the Gross Energy Requirements (GERs) of different office .  buildings Baird et al 1994 note; "...it can be seen that dissimilarities individual  sites and  comparisons •  differences  in layout and  serviceability  due to peculiarities  could  make  of  meaningful  difficult."  Differences between the construction, layout, standards of accommodation and servicing provided and age of the building. (Forintek 1994) These differences are more significant than any differences in the energy intensities of materials and components used. The reported range of embodied energies per square metre of floor area is much greater than the range of embodied energies for individual materials given in the same reports. Stein's embodied energy for offices at 18.6 G J / m  2  is more than four and a half times the 4.02  G J / m found in this study. However when intensities for individual materials are compared 2  the difference is much less, Stein's figure for concrete and steel are less than twice those used in this study. This last item was thought likely to be the most significant in terms of accounting for the wide range of embodied energies reported for office buildings. A further investigation was carried out to determine to what extent differences in embodied energy of complete office buildings is a result of differences in the embodied energy of their constituent materials and components and how much results from differences between the buildings themselves. The values used in a number of previous studies for the energy intensities of each of the ten major materials, or classes of materials, in the study building were determined. Each of these sets of values were input into the study building calculations giving  61  determined. Each of these sets of values were input into the study building calculations giving alternative values of the building's total initial embodied energy based on unique sets of data from each of the previous studies. The results shown in Table 4.4, indicate a lesser degree of variation than is seen when the embodied energy figures for each of the studies individual office buildings are compared. Stein's embodied energy of 18.6 G J / m  2  is almost five times  greater than the 4.03 G J calculated in this study, however Stein's figures applied to the study building are only 8 0 % greater. The greater difference must therefore result from differences in the buildings used in the two studies, which are not described. Table 4.4 Energy intensities from previous studies applied to test building STUDY  Initial embodied energy (a) GJ 56872 55011 36566 34003 33057  Relative to this study % 176.2 170.5 113.3 105.4 102.4  Stein Buchanan & Honey Cole Kohler Danish Building Research Inst. 100.0 This study 32273 93.9 Optimize 30290 (a) The energy intensity figures from the previous studies are applied to the current study building  4 . 6 METHODOLOGY ADOPTED TO CALCULATE EMBODIED ENERGY In calculating initial embodied energy the following procedure was followed. The drawings and description of the study building were used to prepare an itemized list of all of the materials and components in the building. The structure of the list is based on the six building systems discussed in Chapter 2; sitework, structure, exterior enclosure, interior enclosure, finishes and services. Each of the systems is further divided and subdivided to give a series of assemblies and components. For example exterior enclosure is divided into wall, glazing, and roof sections. The walls section is divided into framed walls and shear walls assemblies. Each of the assemblies is a description of all of the materials and components  62  required to construct a given unit of that element; in the case of walls the unit is one square metre.. The complete list of all elements in the building is referred to as the "take-off' or the "materials take-off' and is included in Appendix 4. Table 4.5 Example section of materials take-off EXTERIOR ENCLOSURE Exterior wall assembly framed walls) B 1 A Brick cladding 2  3  Unit  C  D  Qty./m  2  E  F  MJ/unit conv. kg  M  K  G  H  J  MJ/k  MJ  Wst. total MJ qty.  N  O  MJ  %  g  4 5 6  100mm clay brick Mortar Stainless steel ties  no. kg No.  64.00 32.40 3.50  7  Nails  No.  14.00  m no. m m  0.30 1.00 0.30 0.30  8 9  Steel angle Bolts 10 Caulk (polyurethane) 11 Backer rod (polyethylene foam) 12 Total MJ per m2 of component  2.04 1 0.05 7 0.00 5 7.97 0.5  131 2.50 32.40 1.8 0 45  326 58 9  5 5 5  343 61 9  0  45  3  5  3  2 1  28 45  67 23 2 2  5 5 5 5  70 24 2 2  5.7 6.7  490  515 117 2  60301 1.90 3  Table 4.5 above is a representative section from the building's materials take-off list and is included to show the calculation process used to determine the buildings initial embodied energy. •  Column A : A description of each material and component in a particular assembly is given. The example above shows a portion pf the take-off sheet for a framed exterior wall assembly. This subsection details the materials and components required to provide the brick facing to the exterior wall.  •  Column B : Indicates the units used to quantify or measure each material, numbers of bricks, kilograms of mortar, linear metres of steel angle etc.  63 Column C : Lists the quantity of each material to provide one square metre of the overall assembly (in the case of other assemblies it may be the quantity of a particular material required to provide one linear metre of an assembly). Column D: The embodied energy of certain materials has been previously calculated in terms of energy per standard unit or is typically reported in this manner. Where this is the case column D lists this energy,  in the above example the  embodied energy of  polyurethane caulking is indicated as 5.7 MJ per linear metre. Where energy intensity is reported in this manner the quantity in column C of the material is multiplied directly by the energy intensity in column D and the result reported in column H. Column E : For most materials and components however, embodied energy figures are reported in terms of  energy per kilogram, MJ/kg and it is necessary to convert standard  units of measurement to kilograms. Column E gives the conversion factors for each material or component. For example numbers of bricks are converted to kg of brick be multiplying by 2.04 (the mass of a single brick of the type selected). Column F: Lists the mass of the particular material in kilograms, calculated by multiplying the unit quantity of the material in column C by the conversion factor in Column E Column G : Lists the energy intensity of the material in question in terms of energy per kilogram. This is the value specifically selected for this study after analysis of energy intensities of materials from previous studies. Column H: Indicates the embodied energy of the material or component, calculated by multiplying the energy intensity in Column G by the mass of material or component in column F. Column J : A waste factor for each material is estimated and indicated as a percentage. A certain amount of waste is associated with all building activities, whether they take place on  64 or off site. Waste may result from "offcuts" required to adapt materials to specific project conditions, damage to a portion of materials occurring during transportation to, or storage on, the jobsite, rejection of a portion of material not meeting specifications. Waste may also result from over use of bulk materials, which are difficult to measure and place exactly, in order to ensure compliance with specified minimum dimensions. Waste factors have been selected primarily from the Optimize and Forintek studies. •  Column K: Reports the embodied energy of the quantity of material in question including the calculated amount of waste.  •  Column M: Lists the total quantity of the assembly in question required to fabricate the finished building.  » Columns N and O: The energy required for one unit measure of the assembly listed in column K is then multiplied by the quantity listed in column M to give the embodied energy of the materials and components in the total quantity of the assembly in the finished building. The result of this calculation is reported in column N and expressed as a percentage of the total embodied energy of all materials and components in the building in column O.  4.6.1 C o n s t r u c t i o n E n e r g y Direct embodied energy; the final transportation energy and the energy expended at the building site during the construction of the building, is included in the take-off as "construction energy". Based on figures reported in previous studies construction energy has been assumed to be 7% of the total embodied energy of the materials and components in all of the assemblies in the building (Stein 1976 and Salokangas 1990). Construction energy at 7% of the indirect component of embodied energy is thus equal to 6.54% of the total embodied energy of the building.  65  4 . 7 EMBODIED ENERGY ANALYSIS AND RESULTS Table 4.6 below provides a summary of the initial embodied energy analysis of the test building. The total embodied energy is 32,273 Gigajoules or 4.03 G J / m  2  based on a gross  building area of 8 0 1 5 m . Embodied energy is also calculated in terms of energy per office 2  worker. Table 4.6 Initial Embodied Energy of Study Building Quantity 32,273 4.03 110.15  Summary Total embodied energy Initial embodied energy per square metre (a) | Embodied energy per office worker (b)  Units GJ GJ/m GJ / worker 2  (a) Based on a building area of 8015 m (b) 313 workers based on 25.6 m of gross floor area per worker 2  Table 4.7 below provides details of the initial embodied energy breakdown of the test building by material or material type. The mass of each material is also indicated. Table 4.7 Initial building embodied energy (excluding construction energy) and mass by material type MATERIAL TYPE  Energy GJ  Steel - reinforcing Steel - other (a) Concrete Plastics, adhesives, paint etc. Aluminum G l a s s products Bricks, clay products, ceramics Gypsum products Copper W o o d , boards, fiberboard Aggregates, sand, gravel & other  Total  4.7.1 Analysis by material type Steel (11551 G J , 35.8%)  Mass Tonne  %  3923 7928 6601 5206 2231  13.01 26.28 21.89 17.26  1180 1175 909 422 326 260  3.91 3.90 3.01 1.40 1.08 0.86  30161  100.0  7.40  151 201 8441 50 8 63 470 93  % 1.44 1.91 80.37 0.48  8 33 984  0.08 0.60 4.48 0.89 0.08 0.31 9.36  10502  100.0  66  The largest embodied energy component is steel. The major steel constituents are mechanical equipment and attendant distribution systems. H V A C components, air handling units, ducting etc. are primarily fabricated from steel. Most of these elements are manufactured components and require some form of secondary processing, consequently their energy intensity is higher than that of steel elements such as structural steel which require fewer manufacturing steps. Reinforcing steel is also a important component in the concrete structural frame and in belowgrade concrete components. Approximately 3 3 % (3923 G J ) of total steel, or 1 3 % of total initial embodied energy, is accounted for by reinforcing materials.  Concrete (6401 G J , 19.8%) Concrete accounts for 6343 G J of initial embodied energy or 2 0 % of the total. Almost all (97%) of the concrete is accounted for by the building's structural system. This result is perhaps not unexpected. Although concrete has a relatively low energy intensity large quantities of concrete are used. The building contains 3483 m of concrete in the various elements of the structural 3  system.  Plastics, adhesives, paint etc. (5206 G J , 16.1%) This category includes plastics and other materials derived from petrochemicals. Many of these materials have energy intensities in the 100 MJ/kg range, The major components in this material class are roofing membranes representing 1307 G J or 2 5 % of the total. A second major component is carpeting accounting for 1193 G J of initial embodied energy or 2 3 % of the total for this category. Other studies has also identified carpets as contributing significantly to building's embodied energy. Also significant is the polystyrene wall insulation board and the adhesive required for attachment of the boards at 803 G J and 270 G J respectively. It should be noted that roof insulation for the study building is rigid fibre-glass, included under glass products, and not cellular plastic board. Had polystyrene insulation been used on the roof the  67  embodied energy of this section would increase by 608 MJ to 5814 M J and from 16.4% of total embodied energy to 18.3%.  Aluminum (2231 G J , 6.9%) Although not a major component in the building in terms of mass or volume, aluminum is a significant component of total initial embodied energy. Aluminum is amongst the most energy intensive of materials requiring approximately 274 MJ/kg. Almost all of the aluminum, 9 3 % , is accounted for by window and door frames.  Glass products (1180 G J , 3.7%) More than half of the total for this category, 57%, is accounted for by glazing. Window glass, in this case in double glazed units, therefore represents slightly more than 2 % of the total embodied energy of the building or 1% for each layer of glass. Fibreglass insulation accounts for the remaining energy in this category, mainly in the form of roof thermal insulation but also some acoustic insulation in interior partitions.  Bricks, clay products, ceramics (1175 G J , 3.6%) Exterior facing bricks represent 7 7 % of the embodied energy in this category.  Gypsum products (909 G J , 2.8%) Gypsum board which is used as a sheathing material on all framed exterior walls and as a finish material on all interior walls is a major contributor to the overall mass of the building. It has a relatively low energy intensity of 9.8 MJ / kg.  Copper and brass (422 G J , 1.3%) Copper piping and brass valves account for the largest portion of this category with a small amount being found in electrical wiring. In contrast to the previous material the mass of copper in the building is relatively insignificant however its high energy intensity, 50 MJ/kg, accounts for the overall high embodied energy.  68  Wood, boards, fibreboard (326 G J 1 0%) A relatively insignificant component. However it should be remembered that the study building is of non-combustible construction. The use of wood or wood products in buildings of this type is severely restricted. Where buildings are permitted by code to be of combustible construction wood is frequently the material of first choice for many structural, framing and sheathing applications.  Aggregates, stone, sand, gravel (145 G J 0.4%) A relatively insignificant component of initial embodied energy.  The combined embodied energy of two materials concrete and steel at 18458 G J represents more than half (61.2%) of the total initial embodied energy of the building. The major part of this embodied energy, 10143 G J is accounted for by the structural system. After steel and concrete the most significant single material is aluminum at 2231 or 7.4% of the total. The category plastics adhesives and paints includes many and diverse materials and products. However these petro-chemical derivatives represent a significant component of embodied energy, at 17.3% they are only slightly less significant than steel.  4.7.2 Analysis by building system The breakdown of total initial embodied energy amongst the various building systems is given in Table 4.8 below. The largest component is the structural system accounting for a third of initial embodied energy of the building materials.  69  Table 4.8 Initial embodied energy by building system BUILDING SYSTEM  GJ  %  GJ/m  2  tonnes  %  GJ/tonne  Site work Structure Exterior enclosure Interior enclosure Finishes Building services  1361 10143 7758 2586 1802 6512  4.51 33.63 25.72 8.57 5.97 21.59  0.17 1.27 0.97 0.32 0.22 0.81  1054 8448 601 199 52 148  10.04 80.44 5.73 1.89 0.49 1.41  Total (a)  30161  100  3.76  10502  100  1.29 1.20 12.90 13.00 34.92 43.91  (a) Excluding construction energy  Sitework At 4 . 5 % a relatively insignificant component of total embodied energy, however a number of factors should be considered. The site is assumed to be flat and to require no grading or earthworks other than excavation for the building itself. The provision of underground parking within the building greatly reduces the requirement for on-grade access and parking areas, paving, site lighting, drainage etc. All necessary services and utility connections are assumed to be available immediately adjacent to the site. The sitework building systems are project specific and their relative importance may vary greatly.  Structure Structural systems represent by the buildings reinforced concrete frame account for the largest component, 33.6% of initial embodied energy. The structural systems also account for by far the greatest mass of materials in the building. The significance of structure in embodied energy terms is a result of this large mass of concrete and steel. Concrete at 0.75 MJ/kg and steel at 25 MJ/kg are relatively low energy intensive materials, and the average energy intensity of 1.2 MJ/kg makes structural the least energy intensive system in the building.  70  Table 4.9 Structural s y s t e m s embodied energy from p r e v i o u s studies Study  Size (No. of  Location  GJ/m*  % of total  New Zealand New Zealand Japan Canada UK Canada  2.31 3.40 3.38 1.34  49 61 30 26 not available  1.27  33.6  storeys) Honey & Buchanan 1992 Honey & Buchanan 1994 Oka, Suzuki & Konnya Forintek Gardiner & Theobald 1991  2400 (3) Ave. (3-8) 3500 (8) 4620 (3) 3253 (4)  This study  8015(5)  1.27  Table 4.9 above provides details of the structural system embodied energy component of buildings analysed in previous studies and a comparison with the present study. The actual figure of energy per square metre are more significant than percentage of the total as this figure may is affected by the calculated of assumed energy figures for other building systems. For example the structural systems in the present analysis and the Forintek study are essentially the same and the differences in percentages of total embodied energy can be attributed mainly to differences in values assigned to mechanical and electrical systems.  Exterior enclosure At 7758 G J the exterior  envelope assemblies, walls, windows  and roof account for  approximately one quarter of initial embodied energy. The average energy intensity for these components at 12.9 MJ/kg is greater than that of structural and sitework systems.  Interior enclosure Interior enclosure systems comprising principally partitions and doors are at 2586 G J one of the less significant systems in terms of initial embodied energy. Their average energy intensity at 13.0 MJ/kg is almost the same as that of exterior enclosing elements reflecting the face that many of the same materials are found in both systems.  71  Finishes Another  relatively  insignificant  component  of  initial  embodied  energy  representing  approximately 6% of the total. In terms of the mass of material involved finishes are even less significant accounting for less than 1 % of the total building mass. Their greater importance in the embodied energy total indicating a higher than average energy intensity. The average energy intensity of finishes at 34.92 MJ/kg is second only to building services.  Building services Building services at 6512 G J account for 2 1 % of total initial embodied energy. Similarly to finishes they represent a much smaller percentage of total mass and are the most energy intensive system in the building at 43.9 MJ/kg. This high energy intensity is a reflection of the large number of manufactured products as opposed to basic building materials found in mechanical and electrical systems.  4.8 VERIFICATION OF RESULTS Concurrent with the energy analysis a cost estimate was undertaken. The purpose of the cost analysis was twofold. Firstly it was used to verity that the quantities "take-off', used in the embodied energy calculations, was complete and comprehensive, i.e. that it included all materials and components typically found in a building of this type. The second reason was to examine the relationship between embodied energy and costs.  4.8.1 Quantity take-off verification methodology The total cost of all individual assemblies and elements on the take-off was determined using cost figures published in Mean's Construction  Cost Data. The total calculated cost was then  compared with published data from Mean's Square Foot Costs for this type of office building. Mean's Square Foot Costs provides data on the average cost of all building components for a  72  particular building type on a unit area basis, (the figures were converted to metric values for consistency with other data in this study). If the total calculated cost of the individual assemblies and elements is the same as the unit area cost it can be assumed that the list of individual assemblies and elements in the take-off is indeed comprehensive and captures all elements typically found in buildings of this type. Table 4.10 below gives details of the cost derived from each of the sources. Table 4.10 Comparison  of calculated building c o s t based on a s s e m b l i e s  costs Building Test building (1) Typical  5-10  building (1)  storey  office  c o s t s with published s q u a r e foot  Source Means assemblies costs 1993  $ Cdn. Van. 3,761,850  $ per s q . m 469.4  Means square foot costs 1993 p. 166/167  3,753,425  468.3  (1) Excluding: mechanical and electrical, basement and sitework Note: Means square foot costs are converted to square metre costs to be consistent with metric units used throughout this study (1 sq. m = 10.76 sq. ft.)  4.8.2 Quantity Take-Off Verification Results A comparison of the calculated adjusted cost of the test building with the cost of a typical 5 to 10 storey office building shows them to be almost identical, $3.76 and $3.75  million  respectively. It can therefore be assumed that the test building does include all of the elements and components found in a typical building of this type and that there have been no omissions from the materials take-off the total cost of the building including all mechanical and electrical services and site work is calculated at $6,633,462 or $ 8 2 7 / m . 2  4.8.3 Relationship between Embodied Energy and Costs The difficulties associated with the limited extent of information on energy intensities of building materials has been previously discussed. If a close correlation could be found between the embodied energy of materials and their cost, it would be possible to use cost as a surrogate for energy in the analysis of buildings. A large amount of detailed cost data is available for both  73 complete buildings and individual building materials and assemblies. Further more there is a widespread understanding within the construction industry of how costs are  distributed  amongst the various elements and systems in buildings. If it could be established that embodied energy is distributed in the same or similar proportions, cost analysis based on detailed and verifiable information could substitute for less accurate energy analysis. There are arguments to suggest that such a correlation should exist if economic forces are operating efficiently, however market inefficiencies may also operate to negate these arguments. Tables 4.11 and 4.12 below details the results of a comparison between initial embodied energy and costs. Construction embodied energy has been omitted from the analysis as there is no cost information  directly associated with this item. Similarly no embodied energy is directly  attributed to general conditions and so this element has been omitted from the  cost  calculations. The comparison was made between initial embodied energy and capital costs. Capital cost include the costs of all materials and products in the "take-off' and all associated labour required to fabricate the building. The results show no close correlation between the two sets of figures although they do follow a similar broad pattern. The reason for this variation between energy and cost distribution  involves complex economic issues. Analysis and  discussion of this topic is beyond the scope of this study.  74  Table 4.11 Comparison of Initial Embodied Energy and Capital Cost BUILDING SYSTEM  Embodied energy  Percentage  GJ 1361 10143 7758 2586 1802 6512 30161  Sitework Structure Exterior enclosure Interior enclosure Finishes Services Total  Percentage  Capital Cost  % 3 30 15 11 8 33 100  $1000 194 1796 905 635 498 2002 6030  % 5 34 26 9 6 22 100  Variation between cost % and embodied energy % % 40 12 42 -22 -33 -50  A second comparison was undertaken comparing embodied energy with the cost of materials only, omitting labour and equipment rental costs. The results are provided in Table 4.12 below. The intention here was to see if a more direct juxtaposition of embodied energy with the cost of materials would yield a closer correlation. Unfortunately such was not the case and the results in fact show a greater divergence than in the first comparison although again the pattern is similar. Table 4.12 Comparison of Initial Embodied Energy and Capital Cost of Materials (a) BUILDING SYSTEM  Sitework Structure Exterior enclosure Interior enclosure Finishes Services Total  Embodied energy  Percentage  Capital Cost Materials only  Percentage  Variation between cost % and embodied energy %  GJ  %  $1000  %  %  1361 10143 7758 2586 1802 6512 30161  5 34 26 9 6 22 100  (a) The cost of labour and equipment has been excluded.  68 553 403 319 372 1017 2733  2 20 15 12j 14 37 100  60 41 42 -33 -133 -68  general  75  CHAPTER 5 RECURRING EMBODIED  ENERGY  5.1 INTRODUCTION "Traditionally, However,  the approach  the realization  to building cost has been one of 'first cost' considerations  only.  that the 'real cost' of a building does not stop after completion  construction  has become  highlighted  recently  with the advent  of high  maintenance  labour costs. The objective of life cycle costing is to determine  energy  of and  the 'total cost' of  a building over it's lifetime." (RAIC 1978). The relationship between initial embodied energy and recurring embodied energy is similar in many respects to that which exists between initial capital cost and total project costs. Total projects costs in this case include not just the capital costs but also the expense of building operation and maintenance. Initial project development costs may represent as little as 2 5 % of the total project costs. (Shaw 1989) Almost all attention to date in the area of embodied energy investigation has addressed the initial embodied energy of buildings, Optimize 1991 and Cole 1994 are exceptions. Cole (1994) has shown that over the course of a 50 year life span of a typical office building recurring embodied energy can be equal to initial embodied energy. In residential construction it has been estimated that over a 40 year life-span, the recurring embodied energy accounts for as much as 8 6 % of the total recurring embodied energy of a typical single family home. (Optimize 1991) A number of methodological difficulties exist with these previous assessments of recurring embodied energy.  76  •  The most comprehensive study to date of recurring embodied energy, Optimize, is concerned with residential construction. The dynamics of changes in office construction, and therefore of recurring embodied energy, are driven by different concerns.  •  Calculations of recurring embodied energy have typically been based on changes in buildings as a result of regular and predictable maintenance and replacement of materials and components. Replacement is usually based on functional obsolescence, materials and components wear out and are replaced. In reality the nature of change and replacement is much more complex and based on a many different factors.  •  A s s e s s m e n t s of the embodied energy of materials incorporated into buildings in the future are based on current practices and conditions and in particular on current values of energy intensity. Based on historical trends it can be argued that energy intensity in the future will be lower.  5.1.1 Methodology to Calculate Recurring Embodied Energy In calculating recurring embodied energy the same "take-off" spread sheet used to calculate initial embodied energy is used, with additional calculations added to account for future changes in the building. A detailed description of the process and formulae used is provided in Appendix 5. Briefly; a replacement interval is assigned to each material or component on the take-off list. The percentage of the particular material replaced at these intervals is also determined. In certain cases materials are fully replaced and the percentage is 100%,  in others  only a portion material is affected. The same procedure is used in the case of changes resulting from periodic maintenance. Maintenance is considered in all cases to be replacement of a portion of the material of component and therefore is always less than 100%.  Maintenance  typically occurs more frequently than replacement. Based on this information, the additional  77  embodied energy required for maintenance and replacement is calculated at 5 yearly intervals. Recurring embodied energy added to the building at each interval is adjusted to reflect the current level of improvement in the energy intensity of the materials added.  5.2 RESULTS OF RECURRING EMBODIED ENERGY ANALYSIS Table 5.1 summarizes the results of the recurring embodied energy analysis of each of the three future building scenarios described in Chapter 3. In each of the scenarios recurring embodied energy represents the largest portion of total embodied energy, ranging from a high, 2.64 times greater than initial embodied energy in Scenario 1 to 1.41 times greater in Scenario 2. In the case of the third scenario, where the office is converted to an apartment building, recurring embodied energy is 1.21 times less than initial embodied energy. However in this case it should be noted that the embodied energy associated with the materials and components added to the building during the conversion to apartments are counted as initial embodied energy. The conversion process is analogous to constructing a new building and this energy is properly considered as a second installment of initial rather than as recurring embodied energy.  78  Table 5.1 Initial and recurring embodied energies of Scenarios 1, 2 and 3 (100 year lifespan) Scenario 1 GJ GJ/m* Initial embodied energy Recurring embodied energy Total embodied energy Initial as % of total Recurring as % of total Ratio of initial to recurring Average recurring embodied energy per year Average total embodied energy per year  Scenario 2 GJ/m* GJ  Scenario 3 GJ GJ/m*  32273  4.03  32273  4.03  49260(a)  6.15  85314  10.64  45497  5.68  40781  5.09  117587  14.67  77770  9.70  90042  11.23  27.45% 72.55%  41.50% 58.50%  54.71% 45.29%  1:2.64  1:1.41  1:1.79  853  0.11  455  0.06  578  0.07  1176  0.14  778  0.10  900  0.11  Construction energy has been included in all c a s e s (a) Includes embodied energy added during conversion to residential occupancy  Although office buildings are capable of providing useful accommodation for periods of 100 years or more, in many cases and for varied reasons the life-spans of some office buildings may be much shorter. Table 5.2 below provides details of the embodied energy expenditure over a period of 50 years for the buildings in Scenarios 1 and 2. With respect to Scenario 1, recurring embodied energy is still the largest portion of total embodied energy, although less significantly so than in the case of a building with a 100 year lifespan, being 1.61 times greater than initial embodied energy. In contrast, the initial embodied energy of a 50 year building lifespan based on Scenario 2 is 1.16 times greater than recurring embodied energy.  79  Table 5.2 Initial and recurring embodied energies of Scenarios 1, and 2 (50 year lifespan) Scenario 1 GJ Initial embodied energy Recurring embodied energy Total embodied energy Initial as % of total Recurring as % of total Ratio of initial to recurring Average recurring embodied energy per year Average total embodied energy per year  GJ/m  Scenario 2(a) GJ  2  GJ/m  2  32273  4.03  32273  4.03  51958  6.48  27858  3.48  84221  10.51  60131  7.50  38.32%  53.67%  61.68%  46.33% 1:0.86  1:1.61 1039  0.13  557  0.07  1684  0.21  1203  0.15  Construction energy has been included in all c a s e s (a) For a 50 year lifespan Scenarios 2 and 3 are identical  A s previously discussed the primary difference between the first two scenarios is the rate of maintenance and replacement of building materials and assemblies during the course of the buildings lifespan. Comparing the recurring embodied energy figures for Scenarios 1 and 2 with both 50 and 100 year life-spans, it is evident that recurring energy is highly dependent on two factors. •  The lifespan of the building  •  The frequency and extent of replacement of materials and components  Table 5.3 Recurring embodied energy comparison of 50 and 100 year life-spans Scenario 2 Recurring em D. energy Average GJ/m GJ/yr  Scenario 1 Recurring emb. energy Average GJ/m GJ/yr  2  2  50 year lifespan 100 year lifespan  6.48  0.13  3.48  0.07  10.64  0.11  5.68  0.06  In terms of the recurring embodied energy per m  2  the difference in replacement and  maintenance rates (i.e., the difference between scenarios/is considerably more significant that differences due to changes in building lifespan. In the case of buildings with both 50 and 100 year life-spans reducing the level of replacement and maintenance from the Scenario 1 levels  80 to those of Scenario 2 results in savings in recurring embodied energy of approximately 46%. On the other hand, extending the life-spans of the buildings in both Scenarios from 50 to 100 years only results in savings of the order of 1 5 % in the average recurring energy per year.  5.2.1 Impact of Improvement in Energy Intensity An allowance, representing an improvement of 1 % per year, to account for future changes in energy intensity has been included in the recurring embodied energy calculations of each of the scenarios. In addition an allowance of 0.2% per year has been made to account for future increased use of recycled building materials and materials with increased recycled content, both of which will have the effect of reducing embodied energy.  In order to facilitate  comparisons with the results of previous studies, which have not made allowances for these trends, the recurring embodied energy of each of the scenarios has also been calculated without applying the correction factors. A comparison of embodied energy figures for each of the scenarios, with and without the allowances for improved energy intensity and increased recycling, is given in table 5.4 below.  81  Table 5.4 Impact of improvements in energy efficiency of materials and increased recycling Scenario 1 GJ/m* GJ  Scenario 2 GJ GJ/m*  Scenario 3 GJ GJ/m*  117587  14.67  77770  9.70  90042  11.23  85314  10.64  45497  5.68  40781  7.21  Total embodied energy no allowances Recurring embodied energy no allowances  180602  22.53  115296  14.39  105914  13.21  148329  18.51  83023  10.36  56654  7.09  Percentage decrease in total emb. energy with allowances  34.89%  32.55%  14.99%  Percentage decrease in recurring emb. energy with allowances  42.5%  45.2%  28.02%  Total embodied energy with allowances Recurring embodied energy with allowances  Accounting for future changes in these areas clearly has a significant impact on the results of the  recurring  embodied  energy  calculations. Total  embodied  energy  is reduced by  approximately 15 to 3 5 % with recurring embodied energy decreasing by 28 to 4 5 % depending on the scenario.  5.2.2 Detailed Analysis The total embodied energy, initial plus recurring, in Scenario 1 is 117,587 G J , approximately 3.6 times initial embodied energy. Recurring embodied energy is 85,314 G J , 2.6 times greater than initial embodied energy. In this scenario, which has a relatively high rate of materials and component replacement, the recurring embodied energy is the most significant portion of total embodied energy. The comparable figures for Scenario two, 77,770 G J ' t o t a l life cycle embodied and 45,497 G J recurring embodied energy are 2.4 and 1.4 times greater than initial embodied energy respectively. In this instance the recurring embodied energy component is still greater than initial embodied energy but less significantly so.  82  Table 5.5 Recurring and initial embodied energy distribution by building system 1 Building system  Initial embodied energy GJ  Site Structure Exterior enclosure Interior enclosure Finishes Services Construction energy Total  %(a)  Scenario 1 recurring emb. energy GJ %(b)  Scenario 2 recurring emb. energy GJ %.  Scenario 3 recurring emb. energy GJ %  1361  4.22  319  0.37  260  0.57  200  10143  31.43  212  0.25  212  0.47  217  0.53  7758  24.04  15614  18.30  9282  20.40  7831  19.20  2586  8.01  15046  17.64  4018  8.83  2773  6.80  1802  5.58  20837  24.42  11365  24.98  10473  25.68  6512  20.18  27704  32.47  17383  38.21  16621  40.76  2668  6.54  40781  100  2111  6.54  5582  6.54  2977  6.54  32273  100  85314  100  45495  100  0.49  (a) percentage of total initial embodied energy (b) percentage of total recurring embodied energy Scenario 1  5.2.3 Recurring Embodied Energy by System - Comparison with Initial Embodied Energy The materials and building components that account for recurring embodied energy are not uniformly distributed throughout the various building systems. Nor does their  distribution  correspond to the relative proportions of embodied energy within the initial building systems. « Structure: The largest component of initial embodied energy, representing 31 % of the total, is found in structural systems. In contrast structural systems, because of their long lifespans and minimal requirements for maintenance and replacement, represent less than 1 % of recurring embodied energy in each of the scenarios. •  Exterior enclosure: Exterior enclosure assemblies account for approximately  equally  significant portions of both initial and recurring embodied energy, 2 4 % of initial and 18 to 2 0 % of recurring depending on the scenario. •  Building services: A major contributor to initial embodied energy, at 20%, are an even more significant component of recurring embodied energy ranging from 3 2 % in Scenario 1 to 3 8 % in Scenario 2 and 40.8% in Scenario 3. In the case of the third Scenario however it  83 should be remembered that materials and components added during building conversion at year 50 are included as initial embodied energy and that during conversion all or large portions of the building services were replaced. •  Finishes: In contrast to structural elements, finish systems constitute a relatively small part of initial embodied energy but the second largest component of recurring embodied energy, 5.58% of initial and 19.94% to 25.68% of recurring.  Other studies of recurring embodied energy have identified those materials, components and assemblies associated with the "fitting out" process as being the major contributors to recurring embodied energy and have based their calculations on these elements only. (Howard and Sutcliffe 1994) In the classification system used in the present study the interior enclosure, finishes and services systems represent the building "fit out". Taken together these systems account for 33.77% of initial embodied energy but 7 2 . 0 2 % and 7 4 . 7 5 % of recurring embodied energy in Scenarios 1 and 2 respectively. (The concept of "fit out" in this context applies to office rather than residential accommodation and so is not appropriate in the case of Scenario 3). Construction energy in all scenarios and at all times during the lifespan of the building is assumed at 7% of the total embodied energy of all other systems.  5.2.4 Recurring Embodied Energy - Comparison by Scenarios The relative proportions of embodied energy in each of the building systems is broadly similar in each of the scenarios. There are however some significant variations and in comparing and contrasting the relative portions of embodied energy in each, it is necessary to review the nature of changes in building components and assemblies and how they relate to each of the building systems. Changes in siteworks and structure are made for reasons of functional obsolescence or preventative maintenance. Most of the components and materials in these  84  systems have long life-spans, need little maintenance and only minor portions are replaced or repaired. Thus the recurring embodied energy amounts associated with these parts of the building are extremely low in all scenarios. Changes  to  exterior  enclosure  assemblies typically  occur  for  reasons of  functional  obsolescence; roof membrane failure, face-seal failure in walls; or because of technical obsolescence, or a decision to increase the thermal performance of assemblies. Replacement of these assemblies may also take place for aesthetic reasons. Alterations to interior enclosure assemblies, partitions, ceilings and doors, occur in offices, almost exclusively for reasons of aesthetics, or because of minor changes in the use of spaces. These changes are those typically associated with "fitting out" or "tenant improvements". The "high end" office building of Scenario 1 experiences higher rates of turnover of interior enclosure elements, 5 0 % every 5 years, than anticipated in Scenario 2, 2 5 % every 10 years. A s a result the recurring embodied energy for this system is much greater in Scenario 1 than Scenario 2, 15046 G J (17.64% of total recurring embodied energy) compared to 4018 G J (8.83%). Variations in this category are the major differences between Scenarios 1 and 2 and have an impact on the relative percentages of embodied energy in each of the other building systems. For example building services account for 32.47% of recurring embodied energy in Scenario 1 but 3 8 . 2 1 % in Scenario 2. This is not a reflection of greater rates of change in the building systems of the Scenario 2 office but rather of the overall impact of the less frequent turnover of interior enclosure systems. The same dynamic can be seen to a lesser extent in a comparison of finish system in both Scenarios. It is not appropriate to make comparisons between the office accommodation in the first two scenarios and the office and residential accommodation of the third. Although the relative  85  percentages of embodied energy in each of the building systems may be broadly similar, the reasons for changes differ.  5.2.5 Changes in recurring embodied energy Additional embodied energy is incorporated into the building at intervals corresponding to regular replacement and maintenance schedules of between 5 and 50 years depending on the material, assembly or system. Figure 5.1  gives details of recurring embodied energy in  Scenario 1. Figure 5.1 Recurring Embodied Energy - Scenario 1 10000  year  It is difficult to immediately discern any regular or understandable pattern in the graph. However a number of trends are operating concurrently, and have a tendency to confuse the overall picture. Maintenance typically takes place at more frequent intervals of 5 or 10 years. In Scenario 1 replacement due to fit out also occurs at these intervals. Major systems and assemblies in contrast are replaced less frequently at 20 year of longer intervals.  When  86  replacement of these components coincides with replacement and maintenance activities occurring at 5 and 10 year intervals or with other major systems and assemblies replacement it is reflected in the peaks on the graph. Thus in Scenario 1 at year 30, the 5, 10, 15 and 30 year replacement cycles coincide and the embodied energy added at that time is significantly greater than that added during the preceding five year period to year 25. At year 25 additions of embodied energy relate only to regular 5 year activities. Similarly at year 40, the 5, 10 and 20 year cycles coincide to produce another peak occurs. The greatest coincidence of replacement and maintenance cycles occurs at year 60 when 5, 10, 15, 20 and 30 year activities overlap. Predictably another peak occurs at this time, despite the larger number of cycles occurring at this time additional embodied energy is less than that added at the 40 year interval. This is a result of the lower energy intensity of the materials and components added due to the general improving trend in the efficiency of materials industries. Thus although, as would be expected, more materials are added at year sixty than at year 40, the improvement in the energy efficiency of industry over the course of the intervening twenty years has resulted in a lower overall embodied energy addition. A similar situation occurs at the 40 and 80 year periods. The same dynamics exist in the second and third Scenarios although the replacement and maintenance intervals are different and hence the peaks occur at different intervals. The major addition of embodied energy represented by the peak at the 55 year interval of Scenario 3 corresponds to the conversion from office to residential use. Details of the recurring embodied energy of Scenarios 2 and 3 and a comparison with Scenario 1 can be found in Fig. 5.2 below.  87  Figure 5.2 Recurring Embodied Energy - Comparison of Scenarios 10000  S Scenario 1 • Scenario 2 • Scenario 3  5.2.6 Cumulative Recurring Embodied Energy Figure 5.3 shows the cumulative recurring embodied energy of each of the Scenarios. The variations in additions of embodied energy in each of the 5 year periods are less obvious and a more uniform increase in embodied energy is apparent. The cumulative embodied energy represents the total quantity of materials and components that have been added to the building to date rather than the total quantity physically present in the building at that time. Each time embodied energy is added to the building in the form of.replacement materials and components a corresponding or similar quantity is removed.  88  Figure 5.3 Cumulative R e c u r r i n g E m b o d i e d E n e r g y 90000 i  '  10  20  30  40  50  60  70  80  90  100  year  Here the impact of reductions in the embodied energy of materials results in a gradual reduction in the rate of increase which is indicated graphically in a flattening out of the graphs for each scenario. The initial embodied energy of the building, 32273 G J , is indicated by a horizontal"dotted line. By year 30 in Scenario 1 the embodied energy of the materials and components added to the building in replacement and maintenance activities has exceeded this initial investment of energy. With the less frequent replacement and maintenance cycles in Scenario 2 it is only after year 65 that recurring embodied energy exceeds initial embodied energy. The embodied energy associated with the conversion in Scenario 3 results in recurring embodied energy reaching this point at year 55. After this time the rate of increase in recurring embodied energy is in fact slower than in the other two Scenarios.  89  5.2.7 Comparison with Other Studies of Recurring Embodied Energy Few previous studies of embodied energy have attempted to quantify the recurring embodied energy component. Attention has until now been focused in initial embodied energy only. The 1994 Forintek study (1994) in an exception, this study, which models an office building similar in many respects to the study building, has calculated recurring embodied energy for various building life-spans. The calculations of recurring embodied energy in the Forintek study are based on unchanging energy intensity figures and must therefore be compared with the comparable figure in this study, that is with no allowances made for improvements in energy intensity or recycling. W h e n the recurring embodied energy figures have been adjusted the Forintek figure at 15.12 G J / m  2  for a 100 year building falls between the Scenario 1 and 2  figures of 18.51 and 10.36 G J / m respectively. A s previously indicated when improvements in 2  embodied energy are taken into account these figures become 10.64 G J / m Scenario 1 and 5.68 G J / m  2  2  in the case of  in Scenario 2. Two other studies by Howard and Sutcliffe (1994)  and the Davis Langdon Consultancy (1992) have also evaluated recurring embodied energy of buildings. Unfortunately these reports are obtainable only in summary form, detailed figures are not available, and thus comparisons are not possible.  90  Chapter 6  OPERATING ENERGY  6.1 INTRODUCTION Operating energy is the energy required to heat, cool, ventilate and light buildings. Energy used to power appliances, equipment and building systems is also included in this category. Almost a quarter of total energy use in B C is required to operate buildings, with 60 and 40 percent respectively of this energy being used in residential and commercial buildings.  6.2 OPERATING ENERGY OF OFFICE BUILDINGS 6.2.1 Skin versus internal load dominated buildings For the purpose of operating energy analysis, buildings may be divided into two classes; "skin dominated" buildings and "internal load" dominated buildings. In attempting to understand the dynamics of the energy flows that characterize a particular building it is important  to  understand which category the building falls under. Only if the particular attributes of energy flows are understood can appropriate strategies be formulated to reduce overall energy consumption. •  Skin dominated  buildings:  In  these  buildings  the  primary  determinant  of  energy  characteristics is the construction and thermal performance of the building envelope. Energy is used to compensate for heat loss through the exterior skin of the building. Most residential buildings are skin dominated. •  Internal load dominated buildings: The principal determinant in this classification is the nature of the buildings internal loads. Energy is used to provide for, or deal with the  91  consequences, of heating, cooling, lighting and equipment loads. Most non-residential construction, including the study building, falls under this energy dynamic classification. To reduce the overall energy consumption of internal load dominated buildings, the most appropriate and effective strategies are those that are based on controlling and reducing energy requirements for lighting, heating, cooling etc. Strategies that focus on the thermal characteristics and performance of the building envelope will be less effective in this type of building.  6.2.2 Building Energy Performance Index (BEPI) The operating energy performance of office buildings is typically characterized in terms of energy consumption per unit area over the course of an operational year. A unit of measurement in common use is the BEPI (Building Energy Performance Index). The BEPI is typically expressed in GJ/m /yr. BEPI figures for office buildings vary considerably and 2  differences are as likely to result from differences in individual building design and operation as they are from greater or lesser degrees of energy efficiency. In this regard there is no typical office building and it is more appropriate to speak of ranges of B E P I figures for particular classes of buildings. The B E P I s of newer buildings are generally less than those of older buildings. This trend is primarily the result of energy conservation efforts over the last twenty years which have more than compensated for increases in building systems and equipment loads. Prior to these energy saving initiatives in the 1970s studies have shown that the trend was for newer buildings to consume more energy in response to; new building forms (deep plan etc.), user demands for greater control over indoor environmental conditions, and increasing numbers and types of office equipment and appliances. A range of office B E P I s is indicated in Table 6.1 below. A s previously discussed the rate of energy use per building occupant is considered to  92  be of greater significance as it attempts to relate energy use to a quantifiable rate of accommodation of human activity. Unfortunately building energy performance figure are rarely reported in this fashion so comparisons on this basis are difficult to make. Table 6.1 Range of B E P I s (Building E n e r g y Performance Index) from p r e v i o u s studies Year  Study B C Energy Management Taskforce (1) B C Hydro Commercial Building stock study UK - Typical offices (2) U K - Good practice offices (2) Europe - Howard and Sutcliffe (3) B C B C (Post energy program) (5) Average of all North American offices(4)  1993 1993 1993 1994 1986 1986  This study (Base Building)  1994  Low  High  Average  GJ/mfyr  GJ/m*/yr 4.0  GJ/m /yr  0.48 14(a) 0.58 (a) 0.5 0.59  2  1.75 0.97 1.53 (c) 0.83 (c)  2.29(b) 0.85 (b) 2.2 2.0  0.95 •1.4 0.68 (d)  Sources (2) Energy Consumption Guide 19-Energy Efficiency in offices-Energy Efficiency Office Department of the Environment (UK) (3) Howard, N., and Sutcliffe, H., 'Precious Joules', Building, March 18th 1994 (4) Zmeureanu, and Fazio (5) B C Building corporation (quoted in thesis) (a) Naturally ventilated open-plan office (b) Prestige air- conditioned office (c) Standard air-conditioned office (d) B a s e building site energy = 0.68 GJ/m /yr. Source energy = 0.82 G J / m / y r 2  2  6.2.3 Site and source energy In this study a distinction is made between site energy and source energy, particularly as it relates to electrical energy. Thermal generation of electricity (electricity generated from fossil fuels) is extremely inefficient, mainly as a result of inefficiencies in the conversion process from one fuel type to another and distribution from generation to point of use. For example, to generate 1kWh of electricity from coal requires the equivalent in terms of coal energy of 3.3 kvVh. (Optimize) Thus 1 G J of thermally generated electricity energy consumed at the building in fact requires that a far greater amount of energy be consumed in the generation and distribution processes. Source energy is the total amount of energy required to operate the building. It takes into account the additional energy consumed in the conversion process. Site energy is the actual quantity of energy consumed at the site but does not take into account the efficiency of upstream conversion processes. It is important to make this distinction in order that comparisons made between embodied energy and operating energy are consistent.  93 Calculations of energy intensity of building materials typically take into account the sources of energy used in the various acquisition and manufacturing processes and are thus based on primary energy. Approximately 15 percent of electricity in B C is generated from thermal sources, this process has an efficiency of approximately 33 percent. Therefore to supply one unit of site electrical energy requires 1.3 units of source energy ([(0.85 x 1) + (0.15 x 3)] = 1.3). Operating energy figures used in the calculation of the life-cycle energy of the study building and for comparison purposes with other study building energy components, are based on source energy and take into account this conversion factor. Where comparisons are made with the reported operating energies of other buildings the convention of using site energy is followed.  6.3 OPERATING ENERGY OF STUDY BUILDING The study building was modeled using the D O E 2 computer program. This is an energy analysis, D O S based, computer program developed by the Simulation Research Group at Lawrence Berkeley Laboratory. It is a sophisticated modeling and analysis tool capable of handling all aspects of the buildings operating energy flows. Using weather data for Vancouver, and descriptions of the buildings H V A C systems, D O E - 2 generates hourly energy use reports. The program can be used to vary building parameters to improve energy efficiency while maintaining thermal comfort.  6.3.1 Base Building Mechanical and Electrical systems  94  A description of the architectural and structural components of the base building is given in Chapter 2. Table 6.2 below outlines the mechanical and electrical systems and loads used in the D O E - 2 analysis. Table 6.2 B a s e building mechanical and electrical s y s t e m s and loads SYSTEM  Description  Mechanical systems H V A C system Design heat temperature Design cool temperature Ventilation Electrical s y s t e m s Lighting Equipment  Variable air volume with perimeter hydronic base board heaters 21 deg. C 23 deg. C 25 cfm / person 16.8 Watts p e r s q . M 8 Watts p e r s q . M  As discussed in Chapter 2. the base building is designed to meet the requirement of the proposed 1995 National Energy C o d e for Canada which specifies minimal thermal envelope standards for buildings and maximum internal energy loads. It is similar in many respects to the existing City of Vancouver Energy Utilization By-law which incorporates the A S H R A E / IES 90.1 - 1989 Standard (Energy Efficient Design of New Buildings Except Low-Rise Residential Buildings). The study building is thus broadly similar in terms of energy consumption standards to office buildings currently under construction in Vancouver.  6.3.2 Operating Energy of Base Building Table 6.3 gives details of the operating energy of the base building. Lighting at 2211 G J per year is the most significant component of operating energy accounting for 3 4 % of the total. S p a c e heating and auxiliary H V A C together account for 3 1 % of annual operating energy. Lighting and heating therefore represent more than two thirds of total operating energy. The only other significant component of energy use are the elevator and equipment loads at 19.7  95  percent of the total. Service hot water, cooling and equipment together require 12 percent of overall operating energy. Table 6.3 Energy use  Space heating Space cooling Auxiliary HVAC Service hot water (SHW) Lighting Equipment & elevators Total BEPI - G J / m / yr. BEPI - G J / worker / yr. 2  Electricity  Electricity  Site GJ /year  Source G J /year  Natural gas  Total(a)  %of total  Source GJ /year  GJ /year  %  75  97  1610  1707  244  317  0  317  26.1 4.8  736  957  0  957  14.6  0  64  64  1.0  1701  2211  0  2211  33.8  988  1285  0  1285  19.7  3744  4867  1674  6542  100  0  0.82 (b) (Site energy BEPI = 0.68) 20.90 (c)  (a) Source electricity plus natural gas (b) based on a floor area of 8 0 1 5 m (c) based on 313 building workers 2  Table 6 . 4 below provides a comparison of the distribution of operating energy of the study building with results from other comparable office buildings. Table 6.4  Location Heating Cooling Ventilation / fans Auxiliary HVAC total Lighting SHW Equipment & elevators Total  Study building BC % 26.1 4.8  1.  2.  3.  BC  BC  U.S.  %  %  %  28  15.7  30  8  12.8  14 7  15  14.6 (45.5) 33.8 0.98 19.7 100  8  9.5  (59)  (38)  (51)  27  40.9  49  2  0.5  11  20.6  100  100  1. Energy management for commercial buildings B C Min. of E M P R 2. B C Hydro Design Smart 3. Energy Design for Architects  100  96  Chapter 7 LIFE - CYCLE OPERATING ENERGY  7.1 INTRODUCTION The term "life-cycle operating energy" is used to describe the total energy required to operate the building over its operational life span. The difficulty of attempting to calculate life-cycle energy use based on current rates of consumption has already been discussed in relation to embodied energy. This same difficulty arises in attempting to quantify operating energy use through a buildings life span. Although operating energy efficiency is constrained by the efficiencies of existing systems, there will none the less be changes over the course of time. The major determinants of a buildings operating energy use include: •  The macro and micro climatic conditions associated with the buildings geographic and specific site locations  « The nature and efficiency of the energy using systems within the building; H V A C boilers and furnaces, lighting equipment, service hot water heating systems etc. •  The size and nature of internal loads within the building; equipment and appliance loads, occupancy schedules  •  The thermal characteristics of the building envelope  •  The efficiency of building operation, levels of maintenance and preventative maintenance on systems, familiarity on the part of building users and maintenance staff with efficient operating procedures etc.  Over the course of time, the nature of all of these determinants, except macro-climatic conditions, may change.  97  7.2 REASONS FOR CHANGES IN BUILDING OPERATING ENERGY The issues related to these mechanism of change and their effects on building operating  energy will be reviewed in more detail.  7.2.1 Replacement of Service Systems Most building systems and sub-systems wear out and need to be replaced at various stages before the building itself becomes obsolete. This is the case with the numerous service systems within the building which account for operating energy use; H V A C , lighting, electrical service etc. Complete systems are rarely replaced at any one time,  rather  individual  components or sub-systems are periodically upgraded. Replacement intervals will vary from system to system and for different components within systems. W h e n components or sub-systems are upgraded they may not be replaced with identical components. After 20 or 30 years the original equipment may no longer be available, more efficient components, offering better performance or lower costs may be substituted in their place. In this way the operating energy systems of the building are periodically upgraded to the level of prevailing technology. Changes in operating energy resulting from this type of upgrading have been taken into account in each of the study building future scenarios described in Chapter 3 Service systems within the building may also be replaced for reasons other than functional obsolescence. Decisions may be taken to increase the energy performance of the building beyond the level of general technological performance. Its relative position on the scale of efficiency of the overall building stock may improve. A n example of such a move may be seen in the renovation of an existing building in New York City by Croxton Architects to provide  98  offices for the Audubon Society. (National Audubon Society 1994) The renovation, responding to the requirements of an environmentally aware and sophisticated client, provided an extremely low energy consumption building with a performance beyond that required by building code or generally prevailing for that type of building. However such building upgrades of this type are the exception rather than the rule and this type of change is not a part of the future Scenarios for the study building.  7.2.2 Changes in the Thermal Characteristics of the Exterior Envelope The thermal characteristics of exterior enclosure elements have a greater influence on overall energy performance in "skin" dominated buildings, however even in "internal" load dominated buildings such as offices, changes in building envelope assemblies will result in changes in total operating energy. The future scenarios anticipate periodic upgrading of building envelope thermal performance as envelope components and assemblies are replaced.  7.2.3 Decreases in Existing Service Systems Efficiency Building services systems immediately after commissioning, may be assumed to operate at peak efficiency. In order to sustain this level of operating efficiency high levels of maintenance and preventative maintenance are required. In addition building users need to be familiar with efficient operating procedures. In practice the necessary levels of maintenance to achieve optimal operational efficiency are rarely achieved. The tendency is therefore for operating efficiency to decrease slowly as systems and equipment age. A small allowance has been made in each of the future scenarios to account for this phenomenon.  99  7.2.4 Changes in Appliance and Equipment Loads In contrast to changes relating to service systems, changes in the energy loads of appliances and equipment, commonly referred to as plug loads, may occur at any time. Although an essential component of office buildings, equipment, computers and other business machines are not integral to the building and can be readily added or removed at any stage during the buildings lifespan (along with office furniture they may be considered to be a "7th building system" - although not one traditionally dealt with by the construction industry). The trend over the last 30 years has been for the numbers and types of office equipment to increase. It is unlikely that office environments have yet reached saturation point in terms of business equipment and appliances. Various sources have suggested that the number of computers per workplace will continue to rise. However they have also indicated that the energy requirements of those computers has already started to decrease and will continue to do so. This situation may also apply to other types of appliances used in offices and results from advances in technology driven in many instances by efforts to conserve energy. Thus while the numbers of appliances contributing to energy loads in offices is likely to continue rising, with increasing energy efficiency the overall energy requirements of these machines is unlikely to rise significantly and may in fact drop. For this reason no allowance has been made in future scenarios for changing office equipment loads. This is a relatively small component of total operating energy that any changes that do occur are unlikely to have significant overall effect.  7.3 MECHANISMS OF CHANGE All of the above factors have the potential to change the operating energy of buildings. How the operating energy of a particular building will change over time will depend on which of the changes occur and when and how frequently they occur. The mechanisms for some changes are direct and have already been discussed. W h e n these change occur, older existing material  100  and equipment is replaced with newer and typically more energy efficient alternatives. More fuel efficient boilers or insulation materials with greater thermal resistance will be used. There may be one or more reasons for this general improvement. •  Over time there will be technological improvements in the performance of building materials, components and building service equipment. However, new materials and technologies with enhanced performance will be introduced. These improvements are the result of numerous and complex factors, which are beyond the scope of this study. Thus in many instances the upgrading of building elements without a specific intent to improve operating energy performance, at any stage after the initial construction of the building, will often result in energy use reductions. This general technological improvement in materials and systems is another aspect of the improvement in the energy intensity of materials discussed in Chapter 4. Selecting an appropriate rate of improvement is however more difficult in the case of operating energy. Because of the wide range of building types and geographic locations and large variations in operating efficiency even within types, historical trends in building operating energy are more difficult to measure. A rate of improvement of 1.0% per year is selected based on the previously discussed general rate of technological efficiency increases. This is a relatively conservative estimate, recent annual improvements in building operating energy have during the period 1973 to 1988 been closer to 2%. It should be noted that this rate is not suggesting that the operating energy of a particular building will improve at 1 % per annum over time; rather that the efficiency of the available technology that, in part, determines the operating energy levels of buildings improves at this rate. Improvements in efficiency may in fact be masked by increased levels of energy use so that no overall improvement results.  •  W h e n building envelope assemblies and components are upgraded, for reasons unrelated to energy conservation, decisions may be taken to, at the same time, improve their energy  101  performance. S u c h conservation strategies may be initiatives by the building owner to reduce energy consumption and associated costs or they may be part of "Demand Side Management" programs initiated by the local utility company. •  Just as initial building  construction  is subject to  building  codes including  energy  performance codes, changes to the building must also comply with the relevant by-laws prevailing at the time those changes are made. Building codes are periodically updated, the Canadian and British Columbia codes every 5 years, and the trend is that standards of safety and overall performance are increased with each revision. Although codes dealing specifically with energy issues have only recently been introduced the same trends towards increased performance requirements are likely to apply. In certain circumstances building codes do not permit particular building elements to be treated in isolation, a decision to a specific assembly of an existing building, may necessitate that the complete building be upgraded to current standards.  7.4  OPERATING  ENERGY CHANGES IN STUDY BUILDINGS - ALTERNATIVE  SCENARIOS For the purposes of calculating changes in the operating energy  for each of the alternative  building scenarios, certain assumptions were made based on the original study building operating energy performance. Table 7.1 below lists each of the components of operating energy consumption and indicates the percentage of the total that will be affected by upgrading of particular building systems. Details of the future upgrading of mechanical and electrical services and envelope assemblies which will have an impact on operating energy performance are given in Appendix 6.  102  7.4.1 Scenarios 1 and 2 In terms of their impacts on the operating energy of the study building, the nature of the changes described in Scenarios 1 and 2 are essentially similar, the only difference between the two being the timing and frequency of the changes. Table 7.1 Potential impacts on operating energy of life-cycle changes in study building The base building operating energy consumption and breakdown is detailed in the first three columns. The fourth column lists the life-cycle changes in the building which may potentially change operating energy use. The final column indicates the percentage of total operating energy which may be affected  Service  Current energy use  % of total operating energy  Change in level of energy use determined by  % of total  GJ/yr. HVAC  2981  45.5  H V A C system upgrade  31.9  (70%)  Building envelope upgrade walls and glazing roof  SHW Lighting Equipment & elevators Total  64  (20%)  Plumbing upgrade  2211  1.0 33.8  1285  13.5  Changes in numbers and appliances, elevator upgrades  6542  100.0  9.1  (10%)  4.6 1.0 33.8  Electrical upgrade (lighting) efficiency  of  13.5 100.0  7.4.2 Scenario 3 Changes in Operating Energy as a Result of Conversion from Offices to Residential use. Scenario 3 anticipates the building being converted to an apartment building after 50 years. It was not feasible, and probably not necessary within the parameters of this study, to carry out a detailed operating energy analysis on the study building after conversion to residential occupancy. Clearly the operating energy characteristics of these two building types would be different and it can be anticipated that changes will occur in the nature of energy use within the building. Office buildings are internal load dominated buildings while the primary determinant of the energy use characteristics of residential buildings are determined by the design of the buildings exterior envelope elements, walls, glazing, roof etc. Major differences will also relate to the uses of energy within the two building types in particular to the relative percentages used  103  for heating, cooling, lighting, hot water etc. Table 7.2 below details in broad terms the energy use breakdown for typical office and apartment buildings. Table 7.2 Comparison of Energy use by Building Type Energy use  Office building  Apartment building  Lighting Heating Cooling Fans Total  49% 30% 14% 7% 100%  20% 63% 10% 7% 100%  Source: The American Architectural Foundation 1989  Although both the relative components and time schedules of energy use, vary between the 1  two building types the total yearly energy use expressed in terms of energy per unit area is broadly similar. Given the range of operating energy consumption within a particular building type, for example offices or apartments, it is difficult to find appropriate data on which comparisons  between these types of buildings can be based.  The  Building  Energy  Performance Standards ( B E P S ) published by the U S Federal Government provide energy targets for various building types for locations throughout the United States. These figures provide a single source for comparison of the operating energy of both office and multi-family residential buildings and are used to determine the operating energy of the study building after conversion. The target figures, expressed as B E P I s to correspond with figures in this study, for offices (large) and multi-family residential (low-rise) are 0.48 and 0.43 G J / m / y r respectively. It 2  should be noted that the figure for offices is considerably lower than the BEPI for the study office building, however these figures are not intended to reflect current practice rather they are recommendations of achievable energy targets. The overall energy consumption of the apartment building over time is therefore considered to be the same as the Scenario 2 office building. The relative proportions of particular components of energy consumption in Table 7.2 are used to calculate the impacts on future operating energy consumption of the periodic changes to systems and envelope components during the course of the buildings life-span as  104  residential accommodation. It is acknowledged that this methodology is less precise than that used to model the operating energy characteristics of the office building.  7.5 LIFE- CYCLE OPERATING ENERGY - RESULTS The life-cycle operating energy of the study building varies from a low of 502458 G J in Scenario 1 to a high of 563340 G J in Scenario 2. The variation between Scenarios 1 and 2 is approximately 12 percent. These figures represent average B E P I s of 0.63 GJ/m /yr. and 0.70 2  GJ/m /yr. respectively. Initial B E P I s in all cases are 0.82 GJ/m2/yr. Additional details are 2  provided in Table 7.3 below. It should be remembered that the improvements in the operating energy over the course of time are not the result of specific attempts to reduce operating energy. Rather they are a consequence of a general improvement in the energy efficiency of available mechanical and electrical systems which affects the study buildings operating energy as existing systems are periodically replaced. Table 7.3 Life-cycle operating energy -100  year life-span Scenario 1  Total operating energy - GJ As percentage of Scenario 1 BEPI - year 1 - GJ/m /yr BEPI - y e a r l 00 -GJ/mfyr Average yearly operating energy consumption BEPI GJ/m /yr 2  Scenario 2  502458 100 0.82 0.34 0.63  Scenario 3  563340 112 0.82 0.37 0.70  536819 107 0.82 0.39 0.67  2  Figure 7.4 below shows a reduction in energy consumption over the buildings life-span for the 3 scenarios resulting from the periodic replacement of mechanical and electrical systems and components with newer and  more efficient  technology.  Improvements  in the  thermal  performance of the exterior envelope assemblies also have an impact although this is less significant except in the case of the apartment phase of Scenario 3. The major decrease in Scenario 3 operating energy consumption which occurs at year 50 is related to the conversion to apartment use. At that time the energy consumption characteristics change, the building  105  becomes a "skin-dominated" building, at the same time there is a major upgrade of the building's exterior envelope. Other than this change and a less significant upgrade at year 75 maintenance and replacement activities are less frequent than in Scenarios 1 and 2. In all cases approximately 60 percent of total operating energy is consumed during the first 50 years of the building's life span, 60.4%, 5 7 . 9 % and 61.4% in Scenarios 1, 2 and 3 respectively. Annual operating energy (BEPI) at the end of the building's functional life is 0.34 G J / m  2  in  Scenario 1, 0.39 G J / m , in Scenario 2 and 0.37 G J / m , in the third Scenario. These figures are 2  2  respectively 4 1 % , 4 8 % and 4 5 % of the B E P I s of the newly constructed building in the first year of operation.  106  Chapter 8  DEMOLITION ENERGY  8.1 INTRODUCTION Demolition energy is the energy required to physically dis-assemble the building at the end of its operational life and to transport the resulting material to disposal locations, usually landfill sites. At the demolition stage this material has traditionally been considered to be "waste", however this attitude is changing and in the future building materials from demolished buildings may be seen as a valuable resource. Fossil fuel accounts for almost all of the energy required for building demolition.  8.1.1 Relationship to Construction Energy Demolition energy is similar to construction energy in that they both involve the transportation of materials and products and the use of energy, to either assemble them during construction, or to disassemble them during demolition (partial or total). Both involve transportation and assembly / disassembly of essentially the same materials, components and assemblies. However the distances involved in the transportation of construction materials are typically much greater than those associated with demolition waste. Construction materials, particularly in non-residential construction, are sourced at a national and international level. Disposal on the other hand typically occurs at a local level. In addition construction takes place over a much longer period of time and involves many more people than demolition. A s a result the worker transportation energy component of demolition will also be less than the comparable component in construction energy.  107  8.1.2 Categories of Demolition Energy Demolition energy is typically considered to be expended at the end of the building's lifespan when the whole building is demolished. However just as construction energy is not only a component of the initial embodied energy but is also part of recurring embodied energy, so demolition energy is similarly expended at various stages during the entire life of the building. This recurring demolition energy is closely related to recurring embodied energy. A s new materials and components are added to the building (during regular maintenance and replacement schedules, tenant fit-outs, and envelope upgrades) corresponding quantities existing materials are usually removed and disposed of. Thus removal and disposal of obsolete building materials and components occurs not only at the end of the life-span of the building itself but also periodically during the course of the building's lifespan. In this case demolition may not be the most appropriate term for this energy as it is typically used to describe the destruction of the whole building. In many cases materials and components are carefully removed to prevent damage to adjoining elements and finishes. A more appropriate term for this recurring demolition energy would be "disassembly energy". Indeed, in the future, as the percentage of building materials which are recycled becomes more significant and fewer "waste" materials are disposed of, the term "demolition" may not even be appropriate for the final process. However for the purposes of this study demolition energy will be used to describe the energy expended at the end of'the buildings lifespan and "disassembly" energy will describe the recurring expenditure of energy during the course of the its operation. The two categories of energy are therefore: •  Demolition energy: The energy required to demolish the building at the end of its useful life and to dispose of the resulting material.  108  •  Disassembly energy: The energy required to selectively take apart, remove and dispose of particular existing obsolete materials, assemblies and components during the course of the buildings life span. This disassembly is typically a prelude to the incorporation of new materials and components into the building. It can be assumed that in most cases, the mass of material removed will broadly correspond to that of the new material added.  8.2 COMPONENTS OF DEMOLITION AND DISASSEMBLY ENERGY Both demolition and disassembly energy are made up of three components: •  On-site energy  •  Materials transportation energy  •  Worker transportation energy  The same components are also found in construction energy although the relative proportions will be somewhat different.  8.2.1 On-Site Energy This is the energy required to power equipment and tools used in the demolition or disassembly processes. In the case of residential demolition it typically involves the use of back-hoes and power tools. Demolition of commercial construction will require additional heavier equipment and may include the use of explosives. On-site disassembly energy will typically be more selective and on a smaller scale and will require more use of hand tools and less heavy equipment. A s more building materials are recycled this use of smaller tools will increase at both the disassembly and demolition stages.  8.2.2 Material Transportation Energy  109 Material transportation energy is the transportation energy requirements for removal of "waste" building material from the building site to a disposal location. Currently almost all construction waste is disposed of at landfill sites. A number of municipal and private land fill sites exist within the Greater Vancouver Regional District. The travel distance to a suitable disposal site will vary from project to project. Typical round trip travel distances from downtown Vancouver to landfill sites range from 22 km to 54 km to the North Shore Transfer Station and the Burns Bog Land Fill respectively. It should be noted that there are considerable variations in the materials that will be accepted, and fees charged, at different disposal sites and as such waste will not automatically be disposed of at the closest landfill.  8.2.3 Worker Transportation Energy The third component common to both demolition and disassembly is the energy required to transport  workers to  transportation  and from  component  of  the  building  demolition  site  energy  during will  be  these activities. considerably  The  less  worker  than  the  corresponding component for construction energy for a number of reasons. •  Demolition / disassembly requires a much shorter time period than construction. (25 - 50 times less)  •  Demolition / disassembly involves fewer on site workers than construction.  •  Demolition / disassembly involves more mechanized and less labour intensive activities than construction.  8.3 ESTIMATION OF DEMOLITION ENERGY The following sections describe the methodology used to estimate both disassembly and demolition energy. The determination of demolition energy is relatively straight forward and  110  figures are given below. Disassembly energy occurs at intervals during the building's life and can only be calculated in conjunction with recurring embodied energy, the assumption being that as new material is added comparable quantities of existing material is removed. Disassembly energy is therefore determined by first calculating demolition energy as a percentage of the total initial embodied energy and then applying the same factor to the recurring embodied energy figures. The methodology described below and figures from other studies are based on current figures for transportation and thus assume that demolition will occur at the present time. In the case of the study building however demolition will occur at the end of its lifespan, that is in 100 years time. The same general improvements in energy efficiency that operate to reduce embodied energy over time are also assumed to apply to demolition energy. The demolition energy calculation for the study building will therefore be adjusted to reflect this improvement.  8.3.1 On-Site E n e r g y Calculation  Little information  is currently available concerning on-site energy use for demolition or  disassembly. For residential construction, the Optimize study gives a figure of 4800 MJ for the demolition of a typical single family residence. This figure is based on the energy required to operate a back-hoe for 4 to 6 hours and is equal to 13.71 M J / m . 2  The energy required to demolish a concrete framed office building would most likely be greater than that required for a lighter wood framed structure. The Advisory Council on Historic Preservation has published figures for the demolition energy requirements of wood, steel and concrete framed construction. (Assessing the Energy Conservation Benefits of Historic Preservation: Methods and examples, 1979 quoted in Forintek 1994) For concrete and masonry buildings in the 5000 to 1 5 , 0 0 0 m range a figure of 136.2 M J / m is suggested, the 2  2  111  corresponding figures for wood and steel construction are 27.1 M J / m  2  and 81.7  MJ/m  2  respectively. S o m e ambiguity however exists concerning these figures and it is unclear whether the figures just deal with on-site energy or whether they also include transportation. A s transportation  energy is likely to be the  most significant  component  in demolition  or  disassembly energy, the significance of the figures is difficult to assess. Applied to the study building the rate for concrete construction is equal to 3.4% of total initial embodied energy. If transportation energy is not included in the 136.2 M J / m  2  figure, demolition energy may  represent a much more significant percentage of initial embodied energy. For the purposes of this study a unit rate on-site demolition energy figure of 26.51 M J / m  2  is  used. This rate is based on the Optimize figure of 13.71 M J / m which is known to include on2  site energy only. In the absence of other data this figure is adjusted to reflect the different nature of commercial construction demolition by prorating according to the relative costs of both types of demolition. Demolition and disassembly energy essentially represent a direct energy input in the form of, fuel to operate equipment or electricity to power tools. It can be assumed therefore that there will be a close relationship between the costs of demolition and the energy quantities involved. (In the case of the demolition of high-rise buildings in dense urban areas costs may be excessive and not directly related to fuel inputs. These situations are not typical and the costs used in this study are not based on this type of demolition.) Table 8.1 Determination of on-site energy rate for office building demolition. A figure for on-site demolition energy of the study building is calculated by adjusting the residential demolition figure from Optimize to reflect commercial building demolition energy use by prorating based  Optimize (Residential construction) Cost of demolition per m  i  building vol.  On-site energy requirements of demolition (a) (b) (c) (d)  Means construction cost data 1994 Means construction cost data 1994 Optimize 1991 Calculated  $(US) MJ/m*  This study (Commercial construction) (a)  10.25(b)  13.71(c)  26.51(d)  5.30  112  8.3.2 Material Transportation Energy The energy associated with the transportation of materials is determined by multiplying the mass of material involved by the distance traveled and then by an energy consumption rate appropriate to the particular mode of transport involved. Transportation energy = Mass of waste material x Distance traveled x Energy consumption rate (MJ)  (tonnes)  (km)  (MJ / tonne km)  In the case of demolition energy, the "waste" material mass is the total building mass; for disassembly energy calculation material mass removed will be assumed to correspond to the mass of new material added. Transportation distance is the length of a round trip from the site to the landfill disposal site. For the purposes of this study a figure of 35 km is assumed, this represents an average round trip from Downtown Vancouver to a local disposal site. Published figures on the energy consumption rate of moving materials vary greatly. In part this may be due to the different fuel efficiencies of vehicles with different cargo capacities. Haseltine (1975) documents the effect of vehicle size on energy used for transportation. Efficiencies vary from 1.04 MJ/km tonne for a vehicle with a 22 tonne capacity to 12.13 MJ/km tonne for a 0.35 tonne vehicle. The rate for a truck with a 7 tonne cargo capacity is 1.69 MJ/km tonne. Optimize (1991) uses a figure of 4.8 MJ/km tonne for transportation energy, this figure applies to both construction and demolition transportation energy. Table 8.2 below lists published figures for materials transportation energy. Differences may result not only from variations in vehicle capacity but also from different cargo types, road types (highway v urban streets) and load efficiencies. The relatively high figure in the Optimize study may reflect the fact that in single  113  family home construction loads will typically be smaller and that efficiencies associated with larger volumes will not be realized.  Table 8.2 Energy to move 1 tonne of material 1 km. Figures from previous studies Study  MJ/km tonne  Haseltine (1975) (7 tonne capacity vehicle UK) Optimize (1991) Forintek (1993 wood) Diesel truck highway transport (Canada) (a) Baird & Chan (1983) (US) Nemetz (1980) Buchanan & Honey (1994) (New Zealand)  1.69 4.80 1.67 1.18 4.20 1.70 3.80  This study  1.70  (a) Quoted in Forintek (1993 wood)  8.3.3 Worker Transportation Energy Worker transportation energy is calculated by determining the number of man-days worked during demolition, multiplying by the average distance traveled to and from work, per day, and by an energy consumption rate for the mode of transport used. Worker transportation energy = Worker days x Distance traveled per day x Energy consumption rate (MJ)  (no.)  (km)  (MJ/km)  Demolition of the study building is assumed to require 15 working days with an average of 10 workers on site each day giving a total of 150 worker days. The average daily trip to and from the work site is estimated to be 30 km. All trips are assumed to be made by automobile consuming 8.5 litres of gasoline ( with an energy content of 36 M J per litre) per 100 km. (Leggett 1990, Foley 1976) This results in an energy consumption rate of 3 megajoules per kilometer. Thus the worker transportation energy required for demolition of the study building is: 1 5 0 ( n o . ) x 3 0 ( k m ) x 3 MJ/km) = 13500 M J = 13.5 GJ  114  8.3.4 Total Demolition Energy Table 8.3 below combines the values selected above for each of the components of demolition energy to give a total demolition energy figure. Table 8.3 Demolition Energy The highlighted figures detail the components of demolition energy applied to the study building and gives a total demolition energy figure of 970 GJ. Below this are listed a series of other studies and their figures for the various components of demolition energy. These figures are also applied to the study building. In cases where these studies do not list particular components the figures selected for the this  This study Optimize (residential) Haseltine (UK) Baird & Chan (US) Buchanan & Honey(New Zealand) Advisory Council on Historic Preservation (transportation energy assumed to be included) Advisory Council on Historic Preservation (transportation energy assumed to be excluded) Stein  On-site energy rate  On-site energy  Energy factor  Material transport energy  Worker transport energy  Total energy  MJ/m  GJ  GJ  GJ  GJ  As % of initial emb. energy (a) %  744.4 2101.8 740.0 1839.1 1664.0  13.5 13.5 13.5 13.5 13.5  970 2225 966 2065 1890  3.22% 7.38% 3.20% 6.85% 6.27%  26.51 13.71 26.51 26.51 26.51  212.5 109.9 212.5 212.5 212.5  MJ/km tonne 1.7 4.8 1.69 4.2 3.8  136.2  1091.6  n/a  included in site energy  included in site energy  1091  3.62%  136.2  1091.6  1.7  744.4  13.5  1850  6.13%  2  Calculations not available see section 7.6 selow  10.43%  Note: As discussed above these figures represent the energy necessary to demolish the study building at the present time. (a) Initial embodied energy excluding construction energy.  8.4 ESTIMATION OF DISASSEMBLY ENERGY Having established a figure for demolition energy as a percentage of initial embodied energy, the same figure is then applied to life-cycle embodied energy to calculate disassembly energy.  115 The same general technological trends which result in changes in embodied energy over time are assumed to also apply to disassembly energy thus the ratio of demolition to embodied energy remains constant. As general improvements in energy efficiency have already been factored into the calculations of recurring embodied energy, no adjustment for time is required. Table 8.4 below provides details of the disassembly energy associated with each of the three scenarios. Table 8.4 Disassembly energy Scenario 1  Scenario 2  Scenario 3  GJ Recurring embodied energy (a) Disassembly energy at 3.22% (a) Excluding construction energy  I  GJ  GJ  79733  42521  38113  2567  1369  1227  8.5 COMBINED DEMOLITION AND DISASSEMBLY ENERGY The total energy associated with demolition and disassembly is indicated in Table 8.5 below. The previously calculated demolition energy figure based on current practices and efficiencies is listed in addition to the demolition energy requirement based on efficiencies at end of the building's life-span in year 2095 when demolition actually takes place. This figure is determined by applying the 3.22% rate to the actual calculated initial embodied energy figure at that time. As discussed previously the initial embodied energy at a specific period in the future is calculated by assuming a one percent general improvement in energy efficiency.  116  Table 8.5 Combined Demolition and Disassembly Energy Scenario 1 GJ  Scenario 2 GJ  Scenario 3 GJ  970 302 2567 2869  970 302 1369 1671  1480 461 1227 1688  30161 79733  30161 42521  46037 38113  Demolition energy Demolition energy year 2095 (a) Disassembly energy Total demolition and disassembly energy to year 2095 Initial embodied energy (b) Recurring embodied energy (b) Total embodied energy (b) As percentage of initial embodied energy As percentage of Total embodied energy  %  %  %  9.51 2.61  5.54 2.30  3.67 2.01  (a) Initial embodied energy at 2095 calculated at 10061 GJ (b) Excluding construction energy The combined energy required for demolition and disassembly is 2869, 1671 and 1688 G J in Scenarios 1, 2 and 3 respectively. These totals account for between 2.01 and 2.61 percent of total embodied energy, excluding construction energy. W h e n combined with construction energy, assumed to be 7 percent of embodied energy, the direct energy inputs to the construction industry account for approximately 10 percent of the indirect or embodied energy inputs.  117  Chapter 9 LIFE-CYCLE E N E R G Y  9.1 INTRODUCTION Life-cycle energy is the total energy required during the life of the building for all purposes, it consists of each of the components discussed in previous chapters, initial and recurring embodied energy, operating energy and demolition energy. Life-cycle energy is calculated initially on the basis of a 100 year life-span. Table 9.1 below provides a comparison of the lifecycle energy use for the three scenarios. The contribution of each of the components of total life-cycle energy is also indicated. Table 9.1 Life-Cycle Energy (LCE) of study building based on 100 year life span Energy component Initial embodied energy Recurring embodied energy Operating energy Dis-assembly energy Demolition energy Total As percentage of Scenario 1 Total L C E per m Total L C E per occupant Total average L C E per year  Scenario 1 GJ 32273 85314 502458 2567 302 622914  2  % 5.18 13.70 80.66 0.41 0.05 100 100 77.72 1990 623  Scenario 2 GJ 32273 45497 563340 1369 302 642781  % 5.02 7.08 87.64 0.21 0.05 100. 103.19  Scenario 3 GJ 49260(a) 40781 536819 1227 461 628548  80.20 2054 643  % 7.84 6.49 85.41 0.20 0.07 100 100.90 78.42 2008 629  (a) Includes embodied energy involved in conversion to residential accommodation.  9.1.1 General Overview •  In all three scenarios it can be seen that operating energy is by far the largest single component representing 80.66, 87.64 and 85.41 percent of total life-cycle energy in Scenarios 1, 2 and 3 respectively.  118  The second largest category of building life-cycle energy in all scenarios is recurring embodied energy. In the case of recurring embodied energy there is a greater variation between each of the scenarios. Scenario 1 recurring embodied energy accounts for 85,314 G J (13.70 percent of the total), almost twice the comparable figure of 45,497 G J in Scenario 2. The additional embodied energy required in Scenario 3 for the conversion to apartments is included as initial embodied energy. If this energy were considered to be recurring embodied energy the figures for initial and recurring embodied energy would be 32273 G J and 57768 G J respectively. If the figures for initial and recurring embodied energy are combined the total embodied energy accounts for 18.88, 12.10 and 14.33 percent of the total life cycle energy in Scenarios 1, 2 and 3 respectively. The lowest life-cycle energy over the 100 year life span is found in Scenario 1, although the differences between all three are less than 4%. Total life-cycle energy in Scenario 2 being 3.19% greater and in Scenario 3, 0.90% greater, than Scenario 1. While the embodied energy component of Scenario 1 is considerably higher than that of either of the other scenarios,  the  lower  operating  energy  consumption,  resulting  from  more  efficient  mechanical and electrical equipment, is much more significant in terms of overall life-cycle energy use. This situation illustrates a particular relationship between embodied and operating energy. Increasing the embodied energy of the building through  frequent  replacement of materials and components, and specifically of H V A C and lighting equipment with newer and more energy efficient technology, results in decreases in the building's operating energy.  Because operating energy is by far the  most significant  component, the resulting savings far exceed the investment in embodied energy.  energy  119 •  Demolition and disassembly energy together account for less than one half of one percent of life-cycle energy in all cases.  •  Construction energy has not been reported separately from embodied energy but at 7 percent of both initial and recurring would amount to 7692 G J , 5087 G J and 5891 G J in Scenarios 1, 2 and 3 respectively. These figures in turn represent 1.23 0.79 and 0.94 percent of total life-cycle energy consumption in the same scenarios.  Figure 9.1 Life-cycle energy - comparison of Scenarios The energy consumption shown at each 5 year interval represents the total energy consumption in the 5 preceding years 60000 50000 -I  - Scenario 1 -Scenario 2 - Scenario 3  10000 4  10  20  30  40  50  60  70  80  90  100  year  9.1.2 Scenario 1 - Life Cycle Energy Figure 9.2 below summarizes the various energy components of the Scenario 1 office building. The energy requirements of each component are reported for 5 year periods and totals given for both individual components and each 5 year period. •  Life-cycle energy in Scenario 1 amounts to 622914 G J .  120  •  The energy profile indicated in Figure 9.2 results from two main trends; the gradual decline in operating energy consumption over time and the addition of different amounts of embodied energy at various intervals.  •  Greatest energy consumption is in the five year, period between years 15 and 20 with an average annual rate of 8218 G J . The general decline in consumption is interrupted at the 30, 40 and 60 year intervals as significant quantities of recurring embodied energy are added.  •  Annual energy requirement during the last 5 years of the buildings operational life, 3792 GJ/yr is approximately half the comparable figure immediately after construction of the building.  Figure 9.2 Scenario 1 Life cycle energy summary The energy consumption shown at each 5 year interval represents the total energy consumption in the 5 preceding years _ 45000 40000 f 35000 + 30000  3  • Demolition energy B Disassembly energy  25000 - f  • Operating energy  20000  • Recurring embodied energy ffl Initial embodied energy  15000 10000 5000 0  year  The significant influence of the operating energy component on total building life-cycle energy has previously been noted. The operating energy reductions associated with the modest  increased efficiency of mechanical and electrical plant in Scenario 1 more than compensate for an embodied energy component almost double that of Scenario 2. T h e relative insignificance of demolition and disassembly energy is once again evident.  9.1.2.1 Scenario 1 - reduced building life-span A further investigation was undertaken to examine the implication of a shorter building lifespan compared to the 100 years operational life typically modeled in this study. The argument has been made earlier that demolishing buildings after life-spans of 20 to 40 years, as is now common, is extremely wasteful of energy and resources. Table 9.2 below gives details of a comparison between the Scenario 1 building with a 100 year life span and four similar buildings; three with 30 year operational lives followed by one with a 10 year lifespan. Table 9.2 Comparison of Scenario 1 L C E with building replacement Scenario Scenario 1 Study building with 100 year lifespan  GJ Initial embodied energy Recurring embodied energy Operating energy Dis-assembly energy Demolition energy Total  32273 85314 502458 2567 302 622914  GJ/m*  Scenario A Scenario 1 with replacement of initial building after each 30 years (1) GJ GJ/m* 83832 83276 468613 2507 1854 640082  Scenario A percent change from Scenario 1  % 160 -2 -7 -2 514 2.8  (1) Scenario 1 building demolished after 30 years and replaced with comparable building which is in turn demolished and replaced at 30 year intervals. Resulting in a total of 4 buildings, three with 30 year lifespans and one of 10 years, with a combined life span of 100 years.  The difference between the alternative Scenarios in this case is 17168 G J less than 3 percent. Once again the overall importance of operating energy and the modest increase in efficiency of 4 percent, resulting from more frequent replacement of equipment and systems almost compensates for the significant increase, of 42 percent in total embodied energy. A s a result of  122  building four new buildings in place of the single building the initial embodied energy in Scenario A increases by 160%. Because of the decrease over time in the energy intensity of materials there is not a four-fold increase in this component. In the case of recurring embodied energy the four building Scenario A, actually requires less energy than Scenario 1. This primarily results from a significant amount of energy which in Scenario 1 is considered to be recurring embodied energy being defined as initial embodied energy in Scenario A. Several systems and assemblies are replaced at the thirty year period, in addition 5, 10 and 15 year replacement cycles also occur at this time. Because in Scenario 1 these elements are being installed into an existing building they are considered to represent recurring embodied energy. In Scenario A they are also replaced but in this case as part of the replacement of the complete building and are thus classified as initial embodied energy. A further comparison of this type was undertaken comparing the Scenario 1, 100 year building with two similar 50 year life-span buildings. In this case the difference in total life-cycle energy between the two cases is 3700 G J or 0.6 percent. Details of the individual components are given in Table 9.3 below. Table 9.3 Comparison of Scenario 1 L C E with building replacement Scenario Scenario 1 Study building with 100 year lifespan  GJ Initial embodied energy Recurring embodied energy Operating energy Dis-assembly energy Demolition energy Total  32273 85314 502458 2567 302 622914  Scenario B Scenario 1 with replacement of initial building after 50 years (1) GJ 50856 82068 490359 2470 861 626614  Scenario B percent change from Scenario 1 % 58 -4 -2 -4 185 0.6  (1) Scenario 1 building demolished after 50 years and replaced with comparable building Resulting in a total of 2 buildings, each with a 50 year operational life and a combined life span of 100 years.  123  These investigations would appear to suggest that given the current  life-cycle energy  consumption characteristics of office buildings such as the study building, issues relating to operational life-spans are of minor importance. While valid arguments can be made against the waste of resources involved in the premature demolition of buildings, in energy terms these arguments are less compelling. It should be remembered that these analyses deal only with energy and do not take into account the resource issues associated with materials use. Although, with increases in energy efficiency over time, the total embodied energy required to build two new buildings is less than twice the energy required for a single building, this is not the case in terms of material quantities. Successively constructing two similar buildings with 50 year life-spans requires twice the quantities of all materials and components as does the construction of one comparable building assumed to last 100 years. Thus in resource consumption terms there are greater differences between the types of alternative scenarios discussed above than is apparent from an analysis based solely on energy accounting.  9.1.3 Scenario 2 - Life Cycle Energy Figure 9.3 below summarizes the various energy components of the Scenario 2 office building. The total energy requirements for 5 year periods are indicated graphically. Each component of total energy is shown; the importance of the major categories, operating and embodied energy can be clearly seen. Demolition and disassembly energy are almost indistinguishable. « Life-cycle energy, over a 100 year lifespan, in Scenario 2 amounts to 642781 G J or 80.20 GJ/m  2  o The energy profile indicated is broadly similar to Scenario 1 with the same two basic trends operating; a decrease over time in operating energy with periodic additions of different  124  quantities of recurring operating energy. Consistent with the differences between the two alternative scenarios the extent of the decline in operating energy consumption is less than in Scenario 1 as are the amounts of embodied energy involved. •  The greatest energy consumption is in the period between years 25 and 30 with an average annual rate of 8289 G J which is almost identical to the Scenario 1 figure for the period to year 20.  •  Average yearly energy requirements during the last 5 years of the building's operational life, 4260 GJ/yr are approximately 62 percent of the comparable figure during the first year of operation.  Figure 9.3 Scenario 2 Life cycle energy summary The energy consumption shown at each 5 year interval represents the total energy consumption in the 5 preceding years ' . 45000 40000 f 35000 • Demolition energy  30000  B Disassembly energy 25000 20000  • Operating energy • Recurring embodied energy  41  S3 Initial embodied energy 15000 10000 5000  o  .,1  | m m,|» »,|», l  t  o  T  o  ( l  o  11 o  o  1 p  o  o  g  year  9.1.3.1 Scenario 2 - reduced building life-span Two analyses similar to those described above was carried out on the Scenario 2 building to investigate the implications of a reduced building lifespan. T h e results are broadly similar to  125  those in the previous examples and are indicated in Tables 9.4 and 9.5 below. In both cases the improvement in operating energy is more than compensates for the increased energy involved in building replacement.  embodied  Reductions in life-cycle energy of 1% and 1.9% are  achieved when the 100 year building is replaced with a series of buildings respectively  having  50 and 30 year life spans. Table 9.4 Comparison of Scenario 2 L C E with 30 year Building Replacement Scenario Scenario 2 Study building with 100 year lifespan  GJ 32273 45497 563340 1369 302 642781  Initial embodied energy Recurring embodied energy Operating energy Dis-assembly energy Demolition energy Total  Scenario C Scenario 2 with replacement of initial building after 30 years (1) GJ 83832 39307 513527 1183 784 638633  Scenario C I percent change from Scenario 2 % 160 -14 -9 -14 160 -1.0  Table 9.5 Comparison of Scenario 2 L C E with 50 year Building Replacement Scenario Scenario 2 Study building with 100 year lifespan  GJ Initial embodied energy Recurring embodied energy Operating energy Dis-assembly energy Demolition energy Total  32273 45497 563340 1369 302 642781  Scenario C Scenario 2 with replacement of initial building after 50 years (1) GJ 50856 44016 533704 1324 861 630761  Scenario C percent increase over Scenario 2 % 58 -3 -5 3 185 I  I  -1.9 (1) Scenario 2 building demolished after 50 years and replaced with comparable building Resulting in a total of 2 buildings, each with a 50 year operational life and a combined life span of 100 years.  9.1.4 Scenario 3 - Life Cycle Energy Details of the life-cycle energy of the Scenario 3 building are represented graphically in figure 9.4  126  •  Total life-cycle energy in Scenario 3 amounts to 628548 G J or 78.42 G J / m  •  The first half of the building life span is identical to that of Scenario 2. At year 50 a  2  significant quantity of embodied energy associated with the conversion to residential use is added. At this time there is a significant drop in operating energy related to the complete replacement and upgrading of all energy consuming systems. After year 50 the rate of replacement of materials and systems decreases and less embodied energy is added than in either of the other scenarios. A s a result of this reduced rate of replacement the building's energy using systems and envelope assemblies are less frequently upgraded and as a result operating energy consumption remains relatively constant. •  Average yearly energy requirements in the last 5 years of the buildings operational life, 3461 GJ/yr are approximately 52 percent of the comparable figure immediately after construction of the building.  Figure 9.4  Scenario 3 Life cycle energy summary The energy consumption shown at each 5 year interval represents the total energy consumption in the 5 preceding years 60000 50000 -I* • Demolition energy  40000  B Disassembly energy • Operating energy  3 30000  • Recurring embodied energy B Initial embodied energy  20000 10000 l"  o  W I oT  1  o  o  o  o  year  o  o  g  o  127  C h a p t e r 10 REDUCTIONS  IN LIFE-CYCLE ENERGY  10.1 INTRODUCTION The various components of office building energy have been analyzed, and the total building life-cycle energy has been calculated in previous chapters. Strategies to reduce energy consumption will now be investigated and total potential energy savings determined.  10.2 STRATEGIES TO REDUCE BASE BUILDING OPERATING ENERGY Chapter 9 showed that operating energy represents by far the largest constituent of total building Life-Cycle Energy (LCE). It is therefore appropriate that in seeking to reduce overall energy consumption attention first be focused on this component.  10.2.1  Methodology  Having calculated and analyzed the current operating energy of the base building in Chapter 6, a list of possible strategies for reducing operating energy was compiled. Within the construction industry considerable attention over the last twenty years has been focused on the issue of reducing building operating energy and the level and extent of familiarity and expertise among architects and engineers is considerable. A large body of technical literature currently exists addressing means to reduce operating energy. Increasingly much of this information is specific to building type and geographic location. In selecting appropriate strategies to reduce operating energy in the study building a number of criteria were applied: •  Strategies must be based on current construction industry technology and readily available materials and products.  128 •  Energy reduction strategies must not have a negative impact on the quality of the indoor environment. (Certain energy reduction strategies implemented in buildings in the 1970s and 80s were based in large part on reducing to unacceptable levels the overall quantities, and specifically the fresh outdoor air component, of ventilation air supplied.)  e All strategies selected must be capable of being modeled using the D O E - 2 computer program. (Almost all the commonly used methods of energy reduction can be modeled using D O E - 2 , however there are a number strategies involving natural ventilation which cannot be tested.) o Strategies must not alter the basic building form or configuration.  A S H R A E 90.1 provides a series of principals which were used to develop a prioritized list of energy reduction strategies. These principals include: *  Determining, and attempting to reduce the internal and external loads on the building by improving envelope thermal performance, reducing internal lighting and power loads.  •  Integrating and coordinating the individual subsystems to achieve optimal overall energy performance. For example improving the daylighting characteristics of the building to reduce lighting and cooling loads.  *  Improving the performance charcateristics of individual subsystems to achiece maximum energy efficiency.  An iterative process was used in modelling each of the strategies with the D O E - 2 computer program; each strategy on the list is applied to a building that incorporates all of the preceeding strategies. In this way the base building is incrementally upgraded from a typical office building energy standard to a building with a B E P I similar to those achieved in advanced  129  energy efficient office buildings. Seven approaches to reducing operating energy were applied to the base building using the DOE-2 computer simulation model to give a series of alternative designs. Several other strategies were modeled but found to have only minimal impact on overall operating energy. (Including; night venting of the building if interior temperatures exceed 20 degrees C, alteration to the exterior wall / window ratio and an increase in the thermal comfort zone.) The strategies and the design changes involved in the study building are listed in Table 10.1 below. The strategies adopted are designed specifically to achieve reductions in the operating energy of office buildings. The energy characteristics of other building types may differ considerably. For this reason it was not appropriate to apply them to the apartment phase of the third scenario building. Ideally a second set of strategies would be developed and modeled, however given that the present study is primarily focused on the energy performance of office buildings this was considered to be unnecessary. Table 10.1 Strate<jies to reduce operating energy  2.  Strategy Daylighting Heat pump  3.  Glazing  4.  Lighting A (Density) Insulation Equipment Lighting B (efficiency)  1.  5. 6. 7.  Design change Natural lighting used to supplement artificial lighting Replace variable air volume system with heat pump ' system Replace double glazing with triple glazing with low-E glass Reduce lighting load from 16.8 to 12 W / m Increase envelope insulation levels by 100% Reduce equipment and elevator loads by 50% Reduce lighting load from 12 to 6 W / m z  1  10.2.2 Results Table 10.2 below presents the details of the results of applying the reduction strategies to the test building. A total reduction in operating energy to approximately one quarter of the base building level is possible if all of the listed strategies are applied. A number of points should be emphasized, or re-emphasized, in relation to these figures.  130 The operating energy reductions associated with each strategy were achieved by applying that strategy in addition to all preceding strategies in the list. The operating energy consumptions achieved are based on applying currently available technology in year one. They therefore represent base building B E P I s immediately after construction. It is assumed that in the case of life-cycle operating energy consumption the same relative decrease over time would apply to the more energy efficient base building. It has been indicated that at any given time a particular type or class of building will consist of a range of individual structures with widely differing operational energy characteristics. This range will be maintained over time as changes in energy consumption, resulting from the trends discussed in Chapter 6, occur in all individual buildings. Site energy, which relates primarily to electricity use, represents the actual consumption of energy at the site. Source energy takes into account generation efficiency and transmission loses and thus represents the total energy required to produce the site energy. The application of Strategy 5 illustrates the distinction between site and source energy. Increasing the building's envelope insulation levels by 100% results in a decrease in site energy from 2725 G J to 2719 G J however the building's BEPI, based on source energy, actually increases slightly from 3369 to 3386 G J . In addition to affecting overall operating energy, conservation strategies may also result in a redistribution of the total energy amongst the various components of energy consumption. Decreasing heat losses through thermal transfer across the building envelope reduces the heating component of operating energy however it will also increase cooling energy use at times when the building's H V A C system is in cooling mode when envelope heat loss is desirable. Electrical energy use associated with cooling thus increases slightly and when this site energy is converted to source energy the increase in cooling load energy is greater than the heating energy saved.  131  Table 10.2 Impact of energy reduction strategies on total annual building operating energy Energy source  Strategies  Site energy  Site energy  GJ  GJ/m  Base building 5418 Daylighting 4125 1 2 Heat pump 3682 3 Glazing 3058 Lighting load A 2725 4 Insulation 2719 5 Equipment load 2126 6 7 Lighting load B 1990 (a) BEPI - Building Energy Performance Index (b) See text above  Source energy  Source energy GJ  2  0.68 0.51 0.46 0.38 0.34 0.34 0.27 0.25  6542 4873 4510 3816 3369 3386 2614 2437  GJ/m BEPI(a) 0.82 0.61 0.56 0.48 0.42 0.42 0.33 0.30 2  Relative to base building % 100 74 68 59 51 51 40 37  10.2.3 Comparison with Other Studies The overall improvement in operating energy consumption may seen dramatic, it is however in line with operating energy levels currently found in energy efficient office buildings. The International Energy Agency has suggested that operating energy in new buildings can be reduced by 70%. (Flavin and Durning 1988) B E P I s of between 0.1 and 0.3 GJ/m /yr. have 2  been achieved in energy efficient offices in Europe. (Cole 1994) The operating energy target figure for the Jack Davis office building in Victoria was 0.34 - 0.4 G J / m / y r and it was 2  suggested that energy consumption levels of one third of this figure-could have been achieved through  the application of more  Corporation 1990)  rigorous  energy  reduction  strategies.  ( B C Buildings  132 10.2.4  Impact of Operating Energy Reduction Strategies on Embodied Energy  The strategies explored in this study can be broadly divided into three categories, those involving changes in operating systems, those which change the thermal characteristics of the building envelope and those assuming changes in the behaviour of building occupants. The first two types require that changes are made to the physical fabric and building systems with consequent changes in the quantities and types of certain materials and components. Strategies aimed at increasing the thermal resistance of the building envelope typically involve the application of additional insulation materials, with an overall increase in both initial embodied energy and recurring embodied energy. Strategies aimed at reducing the energy required for lighting may involve using fewer but more energy efficient fixtures and lamps and as a result reduce the embodied energy of the building. Table 10.3 below documents the changes in the embodied energy of the Scenarios 1 and 2 study buildings resulting from the implementation of the operating energy reduction strategies. Following the iterative approach employed in the application of the operating energy reduction strategies the embodied energy associated with each strategy also includes the embodied energy associated with the previously applied strategies.  133  Table 10.3 Impact of strategies to reduce operating energy on embodied energy Strategy  1  Base building Daylighting  2 3  Heat pump Glazing  4  Lighting load A  5  Insulation  6  Equipment load Lighting load B  Impact  Additional lighting controls (+5%) No change Additional layer of glass Reduced lighting equipment and fixtures (-5%) Increase wall and roof levels by 100% No change  Reduced lighting equipment and fixtures (-5%) Total additional embodied energy GJ 7  100.0  Scenario 2 Total (a) embodied energy GJ 77770  118021  100.4  78003  100.3  118021 119171  100.4 101.4  78003 78836  100.3 101.4  118706  101.0  78588  101.1  122114  103.8  81122  104.3  122114  103.8  81122  104.3  121673  103.5  80887  104.0  Scenario 1 Total (a) embodied energy GJ 117587  4086  %  %  100.0  3117  (a) Initial plus recurring embodied energy  It can be seen that certain strategies, for example increasing insulation levels in walls and windows (Strategies 5 and 3), increase embodied energy, while others (Strategies 4 and 7) associated with reducing lighting levels may actually decrease overall embodied energy. Others result in no net changes. Overall, the additional embodied energy associated with the application of all operating energy reduction strategies results in a 3.5 percent and 4 percent increase in Scenarios 1 and 2 respectively.  10.2.5 Relative Importance of Embodied Energy as Operating Energy Efficiency Improves One of the contentions of this thesis is that if the operating energy efficiency of buildings continues to improve the relative importance of the other components of life-cycle energy, in  134  particular embodied energy, will increase. Thus while embodied energy is currently of secondary importance when compared to operating energy, if the operating energy efficiency of buildings were to improve at a rate faster than the generally prevailing rate of improvement in energy efficiency, embodied energy might in fact become the largest single component of total life-cycle energy. The results detailed above indicate that dramatic improvements in operating energy can result from the application of existing technology. An investigation was carried out to assess how the relative importance of each of the energy components would vary over the course of the buildings life span if operating energy were to improve dramatically. Two scenarios were tested for comparison. Scenario A applies the maximum reduction achieved, a BEPI of 0.30 GJ/m /yr. (application of all reduction strategies 2  above) to the Scenario 1 building life cycle. Scenario B applies an intermediate level of improvement, a BEPI of 0.56 G J / m / y r (application of the first two strategies) to the same 2  building. The results are detailed in table 10.4 below. Table 10.4 Life-Cycle Energy (LCE) of study building based on 100 year life span - Three scenarios based on alternative operating energies Scenario B (b ) Scenario 1 Scenario A (a Energy component GJ GJ GJ % % % 10.61 32273 6.96 32273 5.18 32273 Initial embodied energy 85314 18.40 85314 13.70 85314 28.04 Recurring embodied energy 183826 60.41 343142 74.02 502458 80.66 Operating energy (c) 0.84 2567 0.55 2567 , 0.41 2567 Dis-assembly energy 0.07 302 0.05 302 0.10 302 Demolition energy 622914 100 304282 100 463598 100 Total . (a) Scenario A as per scenario 1 but with a BEPI of 0.30 GJ/m^/yr. in year one and thereafter the same percentage changes in operating energy as scenario 1. (b) Scenario B as per scenario 1 but with a BEPI of 0.56 GJ/m /yr. in year one and thereafter the same percentage changes in operating energy as scenario 1. (c) Based on source energy 2  In an office building with highly energy efficient operating systems, represented by Scenario A operating energy has been reduced by approximately 6 3 % , from 502458 G J to 183826 G J ,  135 and total life-cycle energy by almost 51 %, from 622914 to 304282 G J when compared to the Scenario 1 building. However at 6 0 . 4 1 % of the total, operating energy is still the most significant component of life-cycle energy. The associated increase in the relative proportion of embodied energy (initial plus recurring) more than doubles the percentage of this component from 18.9% to 38.7%. In Scenario B operating energy decreases by 32 percent and total lifecycle energy by approximately 26 percent compared to the Scenario 1 building. Again in this case operating energy at 7 4 % of life-cycle energy is the most important component with total embodied energy accounting for 25.4 percent of the total. These figures are represented graphically in Figure 10.1 below. Thus while embodied energy does indeed become relatively more important as the operating energy efficiency of buildings improves it is still, even in the most energy efficient buildings, of secondary importance to operating energy over the building's full life-cycle. However if at this stage additional reductions in life-cycle energy were required greater potential may exist in addressing the embodied energy component than is seeking to achieve further efficiencies in already highly efficient operating systems.  136  Figure 10.1 Ratio of operating energy to embodied energy 700000  • Embodied Energy BB Operating Energy  Scenario 1  Scenario 3  Scenario 2  Scenario 1 BEPI = 0.82 GJ/m^/yr, scenario A = 0.30 GJ/hv7yr, scenario B = 0.56 GJ/rrv7yr  .  10.3 STRATEGIES TO REDUCE BASE BUILDING EMBODIED ENERGY In one of the original studies of embodied energy in the construction industry, Stein identified two means by which this component of building energy might be reduced, offers many areas in which energy consumption quantities  of materials  required  and through  can be reduced  material  substitution."  through  "...construction reductions  in  (Stein, 1981)  Reduction of embodied energy of buildings can be achieved in two ways: 1. Through reductions in the energy intensity of building materials: both direct energy and indirect energy 2. Through change the nature of the materials that are used in buildings: a) By means of material substitution (changing the types of materials and products used) b) Through material reduction (changes in the quantities of materials used)  137 10.3.1 Reductions in the Energy intensity of Building Materials - Direct (Construction) Embodied Energy Embodied energy differs from operating energy in that only a small portion of the overall embodied energy associated with the building is actually consumed at the building site. Direct energy or construction energy typically accounts for 7% of the total embodied energy. Even within this small component of embodied energy, a significant portion is accounted for by transportation energy, both for materials and construction workers, and is thus outside the control of the construction industry. Improvements in transport energy efficiency will have an impact however small on overall embodied energy. Trends in construction practices towards increased off-site assembly and use of pre-fabricated components may also result in changes in energy intensity, in this case of assemblies and components rather than materials. The increased use of such practices is driven primarily by cost rather than energy considerations and their impact on overall embodied energy cannot be precisely determined at this time. Given the relatively small portion of overall embodied energy in this category any changes are likely to be insignificant in the context of the overall building. For the purposes of this study reductions in embodied energy of this type may be assumed accounted for in the general improvement in energy intensity over time.  10.3.2 Reductions in the Energy Intensity of Building Materials - Indirect Embodied energy The remainder, and larger part, of the building's embodied energy is expended during the other processes and activities associated with building materials production; raw material acquisition, processing, manufacturing and transportation.  138  Over the course of time improvements in the energy efficiency of many of the industries involved will result in lower embodied energy materials and products. It can reasonably be assumed that the most significant reductions in the overall embodied energy of buildings will result from initiatives taken in these non-construction sectors of the economy. O n c e again changes of this type have been included as part of the general trend improving energy efficiency.  10.3.3 Changes Resulting from Material Substitution One of the most obvious strategies to reduce embodied energy, and the one which has to date attracted the most attention, from designers is that of material substitution. Application of this strategy involves analysis of alternative materials, components and assemblies to determine and compare their embodied energies and the selection of those with the lowest energy values. Comparative analyses of this type typically also include other criteria such as associated C 0 and other emissions. 2  Substitution of materials having higher embodied energy with those having lower embodied energy is a useful and appropriate strategy particularly in cases where the relative energies also coincide with other environmental impacts. However there are a number of methodological difficulties with this approach and the overall reductions achievable, if substitution is the only method employed, may be limited for a number of reasons: •  Currently the level of information available on the energy intensity of building materials and products is limited. Typically studies have focused on the same relatively small number of basic materials. Although these materials, for instance the wood, steel and concrete structural elements analyzed in the Forintek study account for a significant portion of a building's embodied energy, the selection criteria for building structural systems are typically  139 related to issues such as building code requirements and local constructional practice which are outside the realm of the designer. The materials and components where wider choices are available and where decisions can be made by individual architects and engineers are in areas such as finishes and envelope cladding materials. Unfortunately because of the wide variety of choices in these categories, the data currently available on the energy intensity of such  materials  is extremely  limited  and  relatively  imprecise.  Accurate  and  exact  comparisons between alternatives, on the basis of embodied energy, are thus difficult to make. (However, these components and materials are frequently replaced during the building's life span and as improved information is developed there may be considerable potential for reductions in embodied energy through a process of substitution.) Variations in energy intensity may be greater between two sources of the same material than between either source and an alternative material. In such a case, even assuming that accurate information is available, substitution is only viable if the precise source of the material to be used can be specified. Existing contractual and administrative procedures, designed to ensure competitive pricing, make it difficult to specify a single supply source. While such institutional barriers can and should be removed, change is unlikely in the short term. Alternative material choices are not available for many building materials and components. Substitution, in the context of the current building technology, is only be possible in a limited number of cases. For functional reasons, particular building elements must be constructed with specific materials. Foundations'are invariably constructed from concrete, windows are almost always glass, electrical conduits is steel tubing. Compliance with building codes further limits available choices; all non-residential construction above 3-storeys is required to be of non-combustible construction and specification of combustible materials and finishes  140  is restricted. A strategy of substitution is typically only an option in the case of materials as opposed to pre-manufactured components, products and assemblies which account for an increasingly large portion of total construction. The only substitute for a faucet is another faucet, other examples of non substitutable components include, fire hydrants, door handles, furnaces, light switches, roof access hatches, bath tubs and light fixtures. •  In may cases where substitution of materials or products is possible it will be found that the alternative with the lowest embodied energy is already the preferred choice for reasons other than embodied energy.  10.3.4 Analysis of Potential for Energy Reduction through Material Substitution A review and analysis of the complete take-off list of materials and components for each of the scenarios was carried out to determine the potential for reducing overall embodied energy through substitution. Table 10.5 below gives details of the main materials and components substituted. Table 10.5 Substitution of materials in study building Original Material / Component / Assembly Piped utilities - plastic pipes and conduit Concrete sidewalks Exterior wall brick cladding Aluminum window frames Gypsum board ceilings Interior partitions - steel studs Steel furring channels Steel door frames Synthetic carpet Ceramic floor tile Ceramic wall tile Mechanical Electrical  Substitute Material / Component / Assembly Concrete or metal pipes Asphalt sidewalks Exterior Insulation and Finish System Wood window frames Acoustic ceiling tile ceilings Wood studs Wood furring strips Wood doorframes Natural carpet Linoleum Paint 10% reduction assumed 10% reduction assumed  A number of issues arising from the substitution of these materials and components should be addressed.  141  Substitutions are made on the basis of lower initial embodied energy values rather than overall life-cycle figures. In cases where the new materials require additional maintenance or have shorter life span than the originals the same scale of reductions may not be achieved in recurring embodied energy. However the greatest reductions in initial embodied energy are achieved in those systems, exterior and interior enclosure and finish systems where materials and components are typically replaced for reasons other than functional obsolescence. In such cases additional embodied energy resulting from shorter life-spans may not be an issue if the material or component is replaced for other reasons before the end of its operational life span. Substitutions in all cases are made on the basis of alternatives materials types rather than within a particular class of material. Thus ceramic tiles are replaced with linoleum rather than with a ceramic tile with lower embodied energy. Table 10.6 Results of materials substitution strategies  Initial embodied energy GJ Percentage Recurring embodied energy GJ Percentage Total embodied energy GJ Substitution scenario as percentage of original Total life-cycle energy GJ Substitution scenario as percentage of original  Scenario 2 Original  Scenario 2a Substituti on  Scenario 3 Original  Scenario 3a Substituti on  Scenario 1 Original  Scenario 1a Substituti on  32273  27987  32273  27987  49260  42313  100 85314  86.7 67667  100 45497  86.7 36173  100 40781  85.9 33533  100 117587  79.3 95654  100 77770  79.5 64160  100 90041  82.2 75846  100  81.3  100  82.5  100  84.2  622914  600444  642781  628879  628548  614086  100  96.4  100  97.8  100  97.7  Table 10.6 above gives the results of the reductions in embodied energy achieved through the material substitution process. The savings achieved in all scenarios are similar with reductions  142  of 18.7% and 17.5% and 15.8% respectively, in Scenarios 1, 2 and 3. The savings in initial embodied energy are also similar, ranging from 13.3 to 1 4 . 1 % and are lower than those achieved in recurring embodied energy; 20.7% in Scenario 1, 2 0 . 5 % in Scenario 2 and 17.8% in Scenario 3. This results from a wider range of choices in the case of the materials in those categories most frequently changed, enclosing elements and finishes. For example in the case of a building of this type the only permitted alternative structural material would be steel, however there may be as many as 15 to 20 viable alternative flooring materials. In terms of their impact on life-cycle energy the savings resulting from the application of the substitution strategy are relatively insignificant; 3.6, 2.2 and 2.3 percent in scenarios 1, 2 and 3 respectively.  10.3.5 Reduction in Embodied Energy Through Material Quantity Reduction A strategy to reduce embodied energy through reductions in materials may be seen as an alternative to materials substitution. Rather than comparing alternative materials and selecting those with the least energy intensity, materials reduction attempts to minimize the overall quantities of materials used. In this case investigation of the comparative attributes of alternatives is not required and analysis is simply a question of whether a material can be partially or completely omitted. The reductions in materials and components listed below were applied to each of the alternative test building scenarios. •  Storm Sewer: Parts of the sub-surface storm water drainage system has been replaced with surface drainage in swales. Lengths of piped runs have been reduced by approximately 55 percent with an commensurate reduction in the numbers of manholes and road drains.  143 *> Paved surfaces: Paved surfaces are reduced by minimizing the widths and extent of roadways and sidewalks. Areas of vehicular and pedestrian circulation are reduced by 35 and 55 percent respectively. •  Reinforced concrete structural components: The choice of an appropriate building structural system is typically based on criteria of cost, local practice and preference of individual engineers and contractors. O n c e the type of system has been chosen, the design process and methodology limits the potential for material reduction, sizes of members being determined and closely controlled by codes and practices. However at the design level when choices are being made between alternative structural systems there may be considerable differences between material quantities and opportunity for reductions. Table 10.7 below compares the embodied energy per m of comparable alternative structural systems. The 2  system used in the study building has a relatively high embodied energy, and a reduction of 15% in this component is assumed to be feasible. Table 10.7 Comparison of embodied energy of alternative reinforced concrete structural systems Structural system (a)  Per sq. m of area Concrete _3  One-way beam and slab Flat plate waffle slab Flat plate Flat plate with drop panels Study building (flat plate with drop beams)  m 0.21 0.19 0.25 0.24 0.29  Steel kg 19.16 15.60 16.92 18.91 14.61  Emb. energy MJ 841 718 854 887 865  % 94.8 80.9 96.3 100.0 97.5  (a) All designs are for a 7.5m span and live load of 4.8 kPa (100 psf) Source Means Construction Cost Data 1992 (Figures converted to metric)  •  Ceilings: Areas of acoustic ceiling tile are reduced by approximately 80 percent, and gypsum board ceilings by 60 percent. Numerous examples currently exist of office environments where ceilings are omitted and the undersides of floor slabs and services are exposed.  144  « Interior partitions: Non-rated interior partitions are reduced by 6 0 % with a corresponding reduction in the numbers of non-rated door assemblies, e G y p s u m board furring: Furring to concrete walls and columns is omitted completely and replaced with a painted finish applied directly to the concrete, o Floor finishes: Areas of carpet and linoleum are reduced to 4 0 % of their current extent. Concrete floor slabs are exposed in all other areas and are treated with a sealer or painted finish. Table 10.8 provides details of the savings in embodied energy achieved through  the  application of the material reductions described above. Table 10.8 Results of materials reduction strategies Scenario 1 Original Initial embodied energy GJ Percentage Recurring embodied energy GJ Percentage Total embodied energy GJ Embodied energy reduction scenario as percentage of original Life-cycle energy GJ Life-cycle energy reduction scenario as percentage of original  Scenario 1b Reduction  Scenario 2 Original  Scenario 2b Reduction  Scenario 3 Original  Scenario 3b Reduction  32273  27117  32273  27117  49260  43345  100 85314  84.0 59739  100 45497  84.0 34600  100 40781  88.0 33961  100 117587  70.0 86856  100 77770  76.0 61717  100 90041  83.3 77306  100  73.9  100  79.4  100  85.9  622914 100  591322  642781 100  626384  628548 100  94.9  97.4  615575 97.9  Savings in embodied energy of 5.1, 2.6 and 2 . 1 % are realized in Scenarios 1, 2 and 3 respectively. These savings are similar to those achieved through the application of the material substitution strategy. However they are still relatively modest, reducing total embodied  145 energy by between 20 and 25%, and as with the substitution strategy insignificant in their impact on total life-cycle energy.  10.3.6 Reduction in Embodied Energy Through Material Substitution and Reduction Strategies to reduce embodied energy based on substitution and materials reduction are not mutually exclusive. They have been addressed separately in this study for the purposes of analysis and to clarify the effectiveness of each approach. Having determined the absolute and relative reductions achievable with each strategy the combined impacts of the application of both studies can be quantified. Table 10.9 below gives details of the reductions in life-cycle embodied energy when strategies based on both materials substitution and reduction are implemented. O n c e again there is a modest increase in the embodied energy saved achieved but the total impact remains relatively insignificant at 7.3% in Scenario 1 and 4.1 percent in Scenarios 2 and 3.  146  Table 10.9 Results of materials reduction and substitution strategies Scenario 1 Original  Initial embodied energy GJ Percentage Recurring embodied energy GJ Percentage Total embodied energy GJ Percentage Total life-cycle energy G J Percentage  Scenario 1c Reductio n & substitut ion  Scenario 2 Original  Scenario 2c Reductio n & substitut ion  Scenario 3 Original  Scenario 3c Reductio n & substitut ion  32273  23451  32273  23451  49260  36924  100 85314  72.7 49709  100 45497  72.7 28639  100 40781  75.0 28032  100 117587 100 622914 100  58.3 73161  100 77770 100 642781 100  62.9 52090  100 90041 100 628548 100  68.7 64956  62.2  577405 92.7  67.0  616550 95.9  72.1  603246 96.0  10.4 REDUCTIONS IN DEMOLITION AND DISASSEMBLY ENERGY As this is a relatively small component of total life-cycle energy specific strategies to reduce it were not addressed. The relationship between demolition and disassembly energy and embodied energy has been established in Chapter 8. Reductions in embodied energy of the scale discussed in the preceding sections will result in corresponding reductions in both demolition and disassembly energy. However given that demolition and disassembly together amount to less than 3 percent total embodied energy and that the reductions achieved in embodied energy were 5.8% and 3 . 1 % of life-cycle energy in Scenarios 1 and 2 respectively the resultant savings in either case amount to no more than one fifth of one percent.  10.5 TOTAL REDUCTION IN LIFE-CYCLE ENERGY The combined impact of reductions in each of the individual constituents of life-cycle energy is indicated in Table 10.10 below. The relative size of reductions achieved is consistent in all  147  cases with savings of 57.8, 59.2 and 57.4 percent in the life-cycle energy of Scenarios 1, 2 and 3 respectively. Table 10.10 Reductions in total life-cycle energy  Initial embodied energy Recurring embodied energy Operating energy (d) Additional embodied energy (e) Dis-assembly energy Demolition energy Total Total per m Total per worker As percentage of original scenario 2  Scenario 1 32273  Scenario E(a) 23451  Scenario 2 32273  Scenario F(b) 23451  Scenario 3 49260  Scenario G(b) 36924  85314  49709  45497  28639  40781  28032  502458  183826  563340  206100  536819  196397  4086  2500  3117  2567  1497  1369  861  1227  843  302  220  302  220  461  346  622914 77.71 1990  262789 32.79 840 42.2  642781 80.20 2054  262388 32.74 838 40.8  628548 78.42 2008  267542 33.38 855 42.6  (a) Application of all energy reduction strategies to scenario 1 (b) Application of all energy reduction strategies to scenario 2 (c) Application of all energy reduction strategies to scenario 2 (d) Based on maximum reduction achieved, i.e. BEPI of 0.30 (e) Embodied energy associated with operating energy reduction strategies - see table 9.3  By far the greatest reductions are achieved in the operating energy consumption of the study buildings, with savings of approximately 63 percent over the comparable figures in the original scenarios. A s operating energy is the largest component of life-cycle energy and because the reductions achieved in operating energy were of greater magnitude than those in other areas these savings make up the greatest portion of the total possible savings. The improvement in operating energy efficiency accounts for 88.5, 93.9 and 94.3 percent of the overall energy reductions in scenarios 1,2 and 3 respectively. Reductions in embodied energy, initial plus recurring, are less significant, amounting to 37.8% in Scenario 1, 33.0% in Scenario 2 and  148  27.9% in Scenario 3. Savings in embodied energy contribute 12.2%, 6.7% and 6.9% to total savings in the same scenarios.  149  C h a p t e r 11  SUMMARY, CONCLUSIONS AND RECOMMENDATIONS  11.1 SUMMARY OF FINDINGS 11.1.1 Embodied Energy The initial embodied energy of the study building is calculated to be 32273 G J , equal to 4.03 G J / m or 103.1 G J per office worker. There are no significant distinctions in initial embodied 2  energy between the alternative building scenarios as each starts with an identical building. Recurring embodied energy ranges from 85314 G J in the case of the Scenario 1 "high-end" office building to 45497 G J in the less frequently maintained and upgraded Scenario 2 building. The recurring embodied energy in Scenario 3 amounts to 40781 G J if the embodied energy required for the conversion to residential use is excluded from this category. If this energy is considered to be recurring embodied energy, the figure increases to 57769 G J . Total embodied energy is thus 117587 G J , 77770 G J and 90042 G J in Scenarios 1, 2 and 3 respectively. These figures are equivalent to 14.67, 9.70 and 11.23 G J / m  2  in the same  scenarios. Total embodied energy in Scenario 1 is 1.88 times greater than Scenario 2 and 2.09 times greater than of that in Scenario 3. Table 11,1 Embodied energy summary Scenario 1 GJ (GJ/m ) 2  Initial embodied energy Recurring embodied energy Total embodied energy  32272 85314 117587  4.03 10.64 14.67  Scenario 2 GJ/m GJ  32272 45497 77770  2  4.03 5.67 9.70  Scenario 3 GJ GJ/m  49260 40781 90042  4.03 5.09 11.23  150  11.1.1.1 Reductions in Embodied Energy Two strategies, material substitution  and material reduction, are considered to reduce  embodied energy. Each strategy has an impact on both the initial and recurring embodied energy components of the study building. Applying both strategies has the effect of reducing total embodied energy by 37.8 percent, in Scenario 1, 33 percent in Scenario 2 and 24.8 percent in the third Scenario. Total embodied energy is reduced to 73161 G J , 52090 G J and 64956 G J in Scenarios 1, 2 and 3 respectively. Table 11.2 Reductions in embodied energy summary Scenario 1 GJ GJ/m* Total embodied energy (prior to application of strategies) Total embodied energy (with application of both reduction strategies) Percentage reduction  117587  14.67  73161  9.13  Scenario 2 GJ/m GJ  z  Scenario 3 GJ/m* GJ  77770  9.70  90042  11.23  52090  6.50  64956  8.10  37.8%  27.9%  33.0%  11.1.2 Operating Energy The operating energy of the study building is calculated at 0.82 G J / m / y r (site energy = 0.68 2  GJ/m /yr). This figure represents the BEPI (Building Energy Performance Index) of the study 2  building at year one of its life-span and is the same in all three scenarios. The total life-cycle energy operating energy ranges from 502458 G J in Scenario 1 to 563340 G J in Scenario 2. The average life-cycle B E P I s are 0.78 GJ/m /yr, 0.80 GJ/m /yr, and 0.78 G J / m / y r respectively 2  2  2  in Scenarios 1, 2 and 3 based on a 100 year life-span. In comparison with operating energy embodied energy, initial plus recurring, in Scenario 1 represents approximately 23.4 years worth of operating energy. The comparable figures for scenarios 2 and 3 are, 13.8 years and 16.8 years of average annual operating energy. Table 11.3 Operating energy summary Scenario 1 Life-cycle operating energy BEPI - at year 1 - GJ/m*/yr Average annual BEPI - GJ/m /yr 2  Scenario 2  Scenario 3  GJ  GJ  GJ  502458 0.82 0.78  563340 0.82 0.80  536819 0.82 0.78  151  11.1.2.1 Reductions in Operating Energy A series of seven prioritized operating energy reduction strategies are consecutively and additively applied to the study building. The total savings in operating energy result in the B E P I of the base building dropping from 0.82/m reduction  of approximately  63 percent.  2  to 0.30 G J / m When  this  2  in the first year of operation, a  revised  rate  of operating  energy  consumption is applied to the alternative life-cycle scenarios total operating energy is reduced to 183826 G J , 206100 G J and 196397 G J in Scenarios 1, 2 and 3 respectively. These figures represent savings of 63.4 percent in the operating energy of each of Scenarios. Average lifecycle B E P I s based on a 100 year building life are 0.23 GJ/m /yr. 0.26 G J / m / y r and 0.25 2  2  G J / m / y r in Scenarios 1, 2 and 3 respectively. Table 11.4 provides details of the reductions 2  achieved in the operating energy of the study building. Table 11.4 Reduced operating energy summary  Reduced life-cycle operating energy BEPI - at year 1 - GJ/m /yr Average annual BEPI - GJ/m /yr z  2  Scenario 3  Scenario 2  Scenario 1 GJ  GJ  GJ  183826  206100  196397  0.30 0.23  0.30 0.26  0.30 0.25  11.1.3 Demolition and Disassembly Energy The relationship between demolition energy and initial embodied energy, and between disassembly energy and recurring embodied energy has been discussed in chapter 7. Demolition and disassembly energy have been calculated a s being 3.22 percent of initial and recurring embodied energy respectively. Table 11.5 details the demolition and disassembly energy components of each of the scenarios and Table 11.6 indicates the savings achieved.  152  The scale of reductions in these areas reflect those achieved in the corresponding embodied energy categories.  Table 11.5 Demolition and disassembly energy summary Scenario 2  Scenario 1 Demolition energy Disassembly energy Combined demolition and disassembly energy  Scenario 3  GJ  GJ  GJ  302 2567 2869  302 1369 1671  461 1227 1688  Table 11.6 Reductions in demolition and disassembly energy summary Scenario 2  Scenario 1 Reduced demolition energy Reduced disassembly energy Combined reduced demolition and disassembly energy Percentage reduction  Scenario 3  GJ  GJ  GJ  220 1497 1717  220 861 1081  346 843 1189  40.2  35.3  29.6  11.1.4 Life-Cycle Energy The total life-cycle energy in the study building is calculated at 622914 G J , 642781 G J and 628548 G J in scenarios 1, 2 and 3 respectively. The difference between the highest and lowest totals is 19867 G J a variance of approximately 3.2 percent. In all cases operating energy is the largest component accounting for between 80.7 and 87.6% of life-cycle energy. Total embodied energy, initial plus recurring, account for 18.95, 12.1 and 14.3 percent of total life-cycle energy in Scenarios 1, 2 and 3 respectively. Demolition and disassembly energy are in all cases insignificant representing less than half of one percent of life-cycle energy.  153  Table 11.7 Life-Cycle Energy (LCE) of study building based on 1 00 year life span Energy component Initial embodied energy Recurring embodied energy Operating energy Disassembly energy Demolition energy Total  Scenario 1 GJ  32273 85314 502458 2567 302 622914  %  Scenario 2 GJ  %  32273 45497 563340 1369 302 642781  Scenario 3 GJ  %  49260 40781 536819 1227 461 628548  The reductions achieved in each of the individual components of life-cycle energy were combined to give a total potential reduction in life-cycle energy use. Overall life-cycle energy was reduced by between 57.8 and 59.2 percent. Again the greatest part of the overall savings, 92.0, 95.9 and 96.3 percent respectively in Scenarios 1,2 and 3, result from reductions in operating energy.  11.1.5 Other Results In addition to the estimation and analysis of life-cycle energy a number of other supplementary investigations were carried out. •  The relationship between embodied energy and capital cost was studied to determine if a correlation existed which would permit cost analysis to be used as a surrogate for embodied energy analysis. Comparisons were initially made between the embodied energy of the study building and total cost of the building; subsequently the comparison was made with material cost only, excluding the cost of the labour component. In neither case was a direct relationship found between building cost and embodied energy.  •  The current overwhelming importance of the contribution of operating energy to total lifecycle energy and the relative insignificance of other energy components has been clearly demonstrated in the thesis. A s analysis was carried out to determine how the relationship  154  between the various energy components might change if operating energy efficiency were to improve dramatically. The maximum reductions achieved in operating energy, were applied to the Scenario 1 building without changing the other energy components. A s a result the operating energy percentage of total life-cycle energy declined from 81 percent to 60 percent with a corresponding increase from 19 to 39 percent in the case of embodied energy. The relationship between operating energy and embodied energy was also studied to determine what effect, if any, strategies to reduce energy in one category would have on the other. In particular if strategies intended to reduce operating energy would result in the addition of appreciable quantities of extra embodied energy and, if so, how this would compare with the operating energy savings. The total additional  embodied  energy  associated with all of the operating energy reduction strategies was calculated to be 4086 G J in Scenario 1 and 3117 G J in Scenario 2. These figures represent additions to total initial embodied energy of less than 5 percent and are inconsequential in comparison to the approximately 63 percent saving in operating energy achieved. The most important conclusion concerning the relationship between the two categories of energy is that the addition of embodied energy in the form of replacement operating energy systems will invariable result in net reductions in total life-cycle energy. Because of general technological improvements in all economic sectors, new equipment and operating systems will typically be more energy efficient than those they replace. A s a result reductions will be achieved even if there is no specific intent to improve operating energy performance. While designing buildings and their constituent  systems for long life-spans and  reducing  maintenance and replacement is, in principal, an effective means of reducing embodied energy and as a consequence also reducing life-cycle energy, it is not so in the case of  155  operating energy systems. Thus the more frequent replacement of materials, assemblies and services in the Scenario 1 building, while resulting in a recurring embodied energy total almost 90 percent greater that that of Scenario 2 the overall life-cycle energy, is actually less. This overall reduction comes principally from  more efficient  operating  energy  performance resulting from frequent replacement. •  Premature replacement of structurally sound and functional buildings is seen as being unnecessarily wasteful  of embodied energy.  However, once again because of the  overwhelming influence of operating energy on life-cycle energy, the additional embodied energy involved in building replacement may be off-set by associated operating energy savings. The 100 year life-span Scenario 1 building was compared with an alternative scenario in which the same building was replaced at 30 year intervals over the same lifespan. Although the embodied energy component of this new scenario increased by over 42 percent, as a result of constructing three additional buildings, total life-cycle energy increased by a modest 2.8 percent. Another comparison of Scenario 1 with a comparable building replace at 50 year intervals results in an difference in total energy requirement of less than 1 percent. W h e n the same building replacement scenarios were applied to the Scenario 2 building there was a decrease in life-cycle energy of 1.0 and 1.9% respectively in the scenarios involving 30 year and 50 year building replacement cycles.  1 1 . 2 CONCLUSIONS  11.2.1 Current Level of Energy Use and Potential for Reduction Commercial office buildings of this type currently use considerable amounts of energy. The investigation has demonstrated that significant potential for reducing this energy consumption  156  exists. This potential can be realized through the application currently available technology, and by implementing strategies to reduce embodied energy, neither of which will significantly alter the form, layout or operating characteristics of office buildings of this type.  11.2.2 Importance of Operating Energy A review of the total life-cycle energy of the study building shows that operating energy is by far the most significant component. Moreover it can be seen that this area offers the greatest potential for energy reduction, savings of up to 60 percent being possible with the application of currently available technology. Embodied energy in addition to accounting for a much smaller portion of life-cycle energy and also offers less potential for energy reduction, savings being of the order of 30 percent. In view of the disparity between the sizes of these two components of life-cycle energy and between the relative potentials for energy savings, initiatives to reduce overall energy consumption must continue to focus on improving operating energy efficiency. Difficulties arising from the current lack of detailed information on the energy intensity of alternative building materials have been discussed in relation to using embodied energy as a selection criteria. Investigation and calculation of detailed energy intensity figures is a time consuming and expensive undertaking. The current and ever increasing number of different building materials and products available suggest that a great deal of ongoing research will be required before sufficiently comprehensive and current data is available. For these reasons, and given the limited research and design time available to building designers, priority should be given to operating energy reduction strategies in any attempts to reduce overall life-cycle energy.  157  The comparative size of the operating energy component and the scale of the achievable energy savings tends to reduce the relative significance of other energy components.  11.2.3 Importance of Changes Over Time In addition to studying each of the components of life-cycle energy in the context of a total building and investigating the relative significance of each, a major objective of this thesis was to address the idea of changes in energy use over time. Over the course of a buildings life there is a general improvement in technological efficiency across all sectors of the economy, this trend has both direct and indirect impacts on life-cycle energy use in buildings. The importance of including this variable in the energy use calculations has been demonstrated. Table 11.8 below summarizes the results of various energy component calculations carried out in this study and compares them with equivalent figures where no allowance has been made in the calculations to account for energy efficiency changes over time. The significant variance of more than 40 percent, far greater than the differences between the total energies of the alternative scenarios, suggests that this is an issue that cannot be ignored in life-cycle energy analysis. Table 11.8 Comparison of figures with and without allowance for changes in energy efficiency Scenario 1-100 year lifespan Operating energy Recurring embodied energy Total life-cycle energy | Percentage difference  With allowance (a) GJ 502458 85314 622914  Without allowance GJ 657200(b) 148330(c) 843236 35.4%  (a) Study figures with a 1% improvement in energy efficiency over time (b) Plant efficiency factor (allowance for decrease in performance of mechanical and electrical systems overtime) has also been omitted. (c) Recycling factor has also been omitted  158  11.3 RECOMMENDATIONS FOR PRACTICE AND FUTURE RESEARCH 11.3.1 Energy Analysis at Building Scale The results of this investigation have shown the disparity between the scales of the various components of building energy use and the relative insignificance of particular  energy  categories in the context of a complete building. Research on individual components of building life-cycle energy without reference to the wider building context can result in over estimation of the importance of the energy category being studied and consequently of the overall significance of potential reductions. What appear to be significant savings in the embodied energy of particular building elements or systems may be negligible when viewed in the context of the embodied energy of a complete building.  11.3.2 Investigation into Rates of Change in Energy Efficiency In view of the considerable differences in the result of energy analysis when time related changes are taken into account, this is a factor that should be included in all life-cycle energy calculations. Further investigation should be carried out to determine current and historical rates of change in energy efficiency and to predict future changes. In addition, different rates and potentials for improvement in various energy consuming economic sectors should be determined. The similarities between life-cycle cost analysis and energy calculations has been mentioned; life-cycle cost analysis invariably includes factors to account for changing values of money at in the future. The fact that future rates of inflation cannot be accurately predicted or that discount rates include subjective criteria is not considered sufficient reason to omit these parameters from calculations. Having decided, by the very act of conducting life-cycle analysis,  159  that time is an important factor, to ignore one of its major effects results in the analysis being of questionable value.  11.3.3 Rates of Replacement A second critical factor in relation to life-cycle energy analysis in buildings is the nature and frequency of changes in the fabric and service systems of buildings. That changes occur and the  impetus for these changes has been documented. The increasing frequency of  replacement of "fit-out" components and assemblies in "high-end" commercial buildings has focused attention on this issue. However this rate of change is unlikely to be typical of the majority of office buildings, and unfortunately little other data is available. Accurate calculations of life-cycle embodied energy is dependent on realistic determination of replacement rates for all building components and on an understanding of how these rates vary within the range of each category of buildings.  11.3.4 Energy Efficiency and Efficiency of Accommodation The most useful method to report and compare the energy performance of buildings is one which incorporates some measurement of the efficiency of accommodation of human activity. At any given time the total area of office space required, although constantly increasing, is finite and is based on accommodating a particular number of office workers. Thus overall energy efficiency within this or any other category of building can be improved by providing accommodation for the required number of office workers within a smaller total area. The study building provides work space for 313 office workers at 25.6 square metres per worker and, in the Scenario 1 building at a energy efficiency rate of 19.9 G J per worker per year. Accommodating additional workers by reducing the area per worker will not change the energy  160  consumption of an individual building, however by eliminating the requirement for additional office space for those workers it will reduce overall energy requirements of office buildings. Given the wide range of space standards reported for office buildings such improvements in the efficiency of accommodation are entirely possible. This study has throughout  reported  energy consumption figures in terms of energy per worker in addition to the more\ebmmon energy per unit area measurement. Unfortunately few other studies provide data in this format and comparisons are not possible. It is recommended that in future studies relating to energy consumption in buildings provide information to allow analysis of this type to be undertaken.  161  REFERENCES American Society of Heating Refrigeration and Air Conditioning Engineers, A S H R A E Standard 90.1-1989: Energy Efficient Design of New Buildings Except Low-Rise  Residential  Buildings,  and Light Construction  Buildings,  Atlanta G a . , 1989.  Baird, G . and Chan, S.A., 1983, Energy Cost of Houses  Report No. 76, New Zealand Energy Research and Development Committee.  Baird, George, Treleaven, Chris, and Storey, John, 1994: The Embodiment Energy - A New Zealand Perspective,  CIB T G 16, Sustainable  Construction,  of  Embodied Tampa, Florida,  U S A , Nov. 6-9, 1994.  Barlow, J a m e s and Gann, David, Offices into Flats, Joseph Rowntree Foundation, York. Dec. 1993  British Columbia Ministry of Energy, Mines and Petroleum Resources, Energy; Requirements  Forecast  1993  Supply  and  -2015,1993  British Columbia Ministry of Energy, Mines and Petroleum Resources, British Columbia  Energy  Policy; New Directions for the 1990s, 1990  British Columbia Buildings Corporation, Chandler, Kasian, Kennedy Architects Ltd.,, Advanced  Energy Efficient Buildings,  Energy;*  1990.  British Petroleum Company p.I.e., The BP Statistical Review of World Energy, 1994  Brand, Stewart, How Buildings Learn - What happens after they're built, 1994, Viking  Buchanan, A . H . , and Honey, B . G . , Energy construction,  and carbon  Energy and Buildings, 20 (1994) pp 205-217  dioxide  implications  of  building  162  Cole,  Raymond J . , and Rousseau,  Construction:  David (1992)  Energy and Air Pollution  Environmental Auditing for Building  Indices for Building  Materials.  Building and  Environment Vol. 27 No. 1 pp. 23-30 1992  Cole, R. J , , Embodied Energy and Residential Building Construction, Unpublished, University of British Columbia, 1992  Cole, R. J . , Rousseau, D. and Taylor, S., 1991 Environmental Audits of Alternate Structural  Systems for Warehouse Buildings Cole, R. J . ed., Buildings and the Environment, A n International Research Workshop, Queens' College Cambridge University, 1992. Proceedings, Vol. 1: Research Questions  Dully, Francis, Hannay, Patrick, (ed.) 1992: The Changing Workplace, Phaidon  Duffy, Francis, Laing, Andrew, and Crisp, Vic, 1993. The Responsible Workplace, The Redesign of Work and Offices, D E G W and the Building Research Establishment, Butterworth Architecture in association with Estates Gazette.  Edwards, Peter J., Stewart, Peter J., Eilenberg, Ian M., and Anton, Stefan, 1994: Evaluating  Embodied Energy Impacts in Buildings: Some Research Outcomes and Issues, CIB T G 16, Sustainable Construction, Tampa, Florida, U S A , Nov. 6-9, 1994.  Flavin, Christopher and Lenssen, Nicholas, 1994: Power Surge: Guide to the Coming Energy Revolution,. W W . Norton and Co., 1994  Flavin, Christopher, Lenssen, Nicholas, Beyond the Petroleum Age: Designing a Solar Economy, WorldWatch paper 100, 1990  Flavin, Christopher, Durning, Alan, B., Building on S u c c e s s : The Age of Energy Efficiency, WorldWatch paper 82, 1988  163  Howard, Nigel, Sutcliffe, Helen, Precious Joules, Building, 18 March 1994  Leggett, Jeremy, Editor, Global Warming, The Green peace report, Oxford University Press, 1990  Lovins, Amory, B., Energy, People, and Industrialization,  Rocky Mountain Institute,  National Association of Industrial and Office Parks (NAIOP), 1990, America's Future  Office  Needs - Preparing for the Year 2000  National Aububon Society, Croxton Collaborative, Architects, Audubon House, Building Environmentally  Responsible,  the  Energy Efficient Office, John Wiley & Sons, Inc. 1994  National Energy Board, Canadian Energy; Supply and Demand 1990 -2010, 1991.  Oka, Tatsuo, Suzuki, Consumption  Michiya, and Konnya, Tetsuo (1993)  and Amount of Pollutants  The Estimation  due to the Construction  of Buildings.  of  Energy  Energy and  Buildings, 19 (1993) 303-311  Pawley, Martin, Theory and Design in the Second Machine Age  Peet, M.J., The Energy Intensity of Commodities  Produced  Basil Blackwell Ltd. 1990  in Canada,  Energy, Vol. 6, pp.  503-517, 1981.  Pimental, D., et. al. Achieving a Secure Energy Future: Environmental  and Economic  1994, Ecological Economics 9 (1994) pp. 201-219.  Proops, John, L. R., The Use and Abuse of Energy Intensities,  RAIC, Canadian Handbook  of Practice for Architects.  1978  pp. 637-641  Issues,  164  Shaw, Alexander, ed., The American Architectural Foundation, Energy Design for  Architects,  The Fairmont Press Inc., 1989  Simpson, M., and Kay, J . , Availability, Exergy, the Second Law and all that...., University of Waterloo.  Stein, R. G . , Serber, D. and Hannon, B., 1976, Energy Use for Building Construction,  Centre  for Advanced Computation, University of Illinois, and R. G . Stein and Associates. U.S. Department of Energy, E D R A Report  Stein, Richard, G , Architecture  and Energy,  Conserving  Energy  through Rational  Design,  Anchor Press, 1977  Stein, Richard, G , Analysis and Reduction  of Energy use in the Building Industry (Paper, no  date)  Urushizaki, N., Kamioka, T., Kaneko, C , Sugiyama, S., Research Resources  and Exhausted  Fixed  Carbon Dioxide by Buildings in Japan.  United States, Department of the Environment, Survey Characteristics Buildings  on Life-cycle  of  Commercial  1986 in Progressive Architecture, Commercial Building Myths, Feb. 89 p103-105  Vale, Brenda, and Robert, Green Architecture;  Design for an Energy-conscious  Future, 1991.  Zmeureanu, Radu, and Fazio, Paul, Analysis of the Energy Performance of Office Buildings in Montreal in 1988, Energy and Buildings, 17 (1991) pp. 63-74  West, J . , Atkinson, C , and Howard, N.P., Embodied Energy and Carbon Dioxide Emissions for Building Materials, Proceedings of CIB International Conference on Buildings and the Environment: Materials Session, B R E , UK, May 1994  Appendix 1 B A S E BUILDING  DRAWINGS  • Drawing A1  Site Plan  © Drawing A2  Basement Plan  © Drawing A3  Ground Floor Plan  • Drawing A4  Typical Floor Plan  • Drawing A5  Elevations  166  DRAWING a 2  BASEMENT PLAN  DRAWING A3  GROUND FLOOR PLAN  DRAWING A4  TYPICAL FLOOR PLAN  170  Appendix 2 SCENARIO 3 - RESIDENTIAL  © Drawing A6  Typical Floor Plan  BUILDING  DRAWING  172  173 Appendix 3  PREVIOUS STUDIES OF EMBODIED ENERGY Stein et. al. (1981) Handbook of Energy Use for Building Construction Location: Date: Main Sources:  United States 1981 (Original study 1976 using energy data from 1967 which was the most recent available) Input / output data from Bureau of Economic Analysis of US dept. of Commerce and process analysis of over 400 materials and products.  • The first major study of construction related embodied energy. • Although much of the data is too out of date to be directly applicable today it is useful for making comparisons between different materials and components. • Comprehensive range of data covering almost all building materials in use at the time in addition to information on a range of component sizes within each material / component category. o In addition to information on individual materials and products the study also provides energy data on construction assemblies and on complete buildings. • One of the few studies to date which provides data on mechanical and electrical systems.  Baird and Chan (1983) Energy Cost of Houses and Light Construction Buildings Location: Date: Main Sources:  New Zealand 1983 Estimated from input-output tables (1971 -72)  a Preliminary investigation into energy requirements for house construction in New Zealand. • Provides embodied energy data for individual building materials, construction assemblies and a generic house. • References to, and comparisons, with other studies of embodied energy are also made.  Buchanan and Honey (1994) Energy and Carbon Dioxide implications of Building Construction Location: Date: Main Sources: o  New Zealand 1994 Based on Baird and Chan's 1983 study with minor additions.  Uses Baird and Chan's data to carry out embodied energy analyses of a series of building types, commercial, residential and industrial.  174 • Examines the implications of alternative structural systems based on wood, steel and concrete components.  Environmental Research Group UBC (1992) Environmental Auditing for Building Construction: Energy and Air Pollution Indices for Building Materials Location: Canada Date: 1992  Environmental Research Group UBC (1991) Environmental Audits of Alternate Structural Systems for Warehouse Buildings Location: Canada Date: 1991  Optimize - CMHC (1991) A Method for Estimating the Lifecycle Energy and Environmental Impact of a House Location: Date: Main Sources:  Canada 1991 Statistics Canada Input / Output Model for the Canadian Economy. Refinements were made to the data to include feedstock energy.  • Report with an accompanying computer program designed to calculate the embodied energy and other environmental impacts of residential construction. o Provides up to date and comprehensive Canadian data on the embodied energy of may common building materials used in residential construction. • Optimize also provides comprehensive and detailed background information on energy analysis methods. • The spreadsheets used to calculate embodied energy in the present study are largely based on the optimize computer model.  Forintek Building Materials in the Context of Sustainable Development (3 reports) Location: Date: Main Sources:  Canada 1993 Process analysis  • Joint study by representatives of the Canadian Steel, Concrete and Wood industries. • Investigation and comparison the overall environmental impacts of each of the three materials as structural components of building systems. • The energy intensity figures (called unit factors) are based on detailed analysis of the acquisition, transportation, and manufacturing processes of each of the industries. • Detailed breakdown of embodied energies are given for a series of components within each of the three material categories.  175 « Regional differences in processes and direct energy sources are recognized and reflected in the embodied energy data. • These reports represent the most accurate, current and geographically specific data available for the embodied energy of these materials. • Range of materials covered by the study is limited to wood, steel and concrete structural components however these materials represent a significant portion of the embodied energy of buildings.  Edwards et. al. Evaluating Embodied Energy Impacts in Buildings: Some Research Outcomes and Issues. Location: Date:  Australia 1994  Baird et. al. The Embodiment of Embodied Energy - A New Zealand Perspective Location: Date: Main Sources:  New Zealand 1994 Baird and Chan's data revised and updated where necessary  • Analysis of alternative structural systems for a 5 - storey office building, primarily concerned with initial embodied energy. • Discusses the advantages of comparing alternative designs for a theoretical building rather than built examples. • As the study buildings are of a similar design the results of this study will be compared in detail with the appropriate results from the present study in later sections.  Appendix 4 MATERIALS TAKE  OFF  177  Appendix 4 Materials take-off SITEWORK  6 STOREY CONCRETE-FRAMED OFFICE BUILDING WITH UNDERGROUND PARKING  siTEf5|p_.ZIZII...ZZl.Z  I  !_  H ZH i  _!  ZZZZZZZLZZZZ.  I ] lUnits :Qty". [ E x c a v a t i o n P " " " j m 5 " " I O ^ b ' j Z  [._..„ Z Z m  iWst.  l i^9_  jmj/unit Iconv.' [kg ! P j Z Z Z Z Z T ~ Z ^ . Z Z J  _  mj total  i qty.  """47'i  SITE SERVICES ASSEMBLIES Qjy_/m_ !Bedding._sand_ i Backfilling ! 150mm die. pvc pipe  I Tracer wire [\4ga^strandjid roppe^ Total mj per m ol component f  im3 jm3 jm  0  ! Water supply accessories  20"']"  2t"i'"  578 i j  I  1 mj/unit Iconv. T561 3800 i « o t ' 3 ' ToopLl Tool" ~5001 14951 2.40 "TOO "'2000T  rnj/kg__  iQty. k y! '* l^°ny„ " i ' "O'iAl 50]""  !mfc/kc[_  I Qty.  I Hydrants  |Wsl. mj total 15 5.00 ^0i____500 35 i ~ 34"! '_ 5.00 "Mi"" "459"T" 5 0C  50! '459]'"  681  TboT Twr  \™ _j  !mj/kg_  mj/unit  38001 5.00_ "loooT Too  _  ! Valve boxes  IValves iConc. thrust blocks (6no. 20mpa) jWater meter i _ j Total mj J !Gos pipe  j  "  }__  I  [  lExcavation j I iBeddmgsand i ] iBacktilling ! I j5bmmdia.poryethyjenepip_e } Tracer wire (14ga stranded copper) jfotajmj per moi component j [Gas supply accessories [ •. j. . . iGas meter 1 jVaive boxes j_ _ i Valves i jTatal m| |  | ! | ! i  lEiectricity and tei. supply  Units  m  __ EiZ m m3  "]0.30!  Sanitary sewer Excavation Bedding sand Backfilling 250rhm dia. abs pipe Tracer wire (14qa stranded copper) Total mi per m of component •  Excavation Backfilling^ Concret base 2Jmpa Rebar, no. 4 Benching [Concrete shaft iReinforctna mesh 1 Concrete lid i i Rebar. no.4 1  501 '""  20! '5.00T ""220 j~  I  I  •  Qty.  m  ! kg j  mj/kg  mj/unit conv. 3000  kg  mj/kg  mj/unit conv. . 0.78 50 0.33 90, • 0.45 50 1.00 316 1.00 20  kg  Qty".  Units m3 m3 m3 m m  Qty  Units m3 m3 m3 m m  Qty.  h  1.00  0.78 0.33 0.45 1.00 1.00  mj/unit  50 90 50 996 20  conv.  -  r  m  55 29 39 376 348 150 150 1147 mj  mj/kg  kg  Units' Qty. mj/unit conv. "kg m3 i 4,00 50 [m3 2.00 50 m3 0.34 1435 m ,_ 14.00 0.99 m3 0.20\ ~ 1495 m 3 052 1 4 9 5 „ m2 i 5.00 7 ST"1"'"0"22 1495 a'.b'b 6.99" 42.00 214.2 2.04 '""{kg "[""20.00 1.8 ino. 4500 100 |na j"TOO 202.5 i.s T r t o P " ~ 3 M  21  Zy]l  I  m| mj/unrt Iconv. jkg i j/^9 i i l^st 20001 i I 2000! 0.00 1.00 3.00 f o w l " 1 1 1 M o T " " " 4 . 6 ' b j ' 100 "fob 600 OO . Oj 5600 - j — -  Units" no. no.' no. -  ZZZZZZEZZZI ZZZlZZI. ZZZ  ~" [Brick 1 Mortar | jCasi iron cover and frame ]Ladder rungs j jTotaJ mj per component  _5"'b .ro"(_ iir"'""' 5:00! • "1'5'oT 5.001  "!' """Too] ""20T  Electricity and telephone supply accessories j Units Put! box (concrete) no. Total mj _j Storm sewer ! j Excavation I Bedding sand i BacWilling 1 250mm dia. concrete pipe Tracer wire (14qa stranded copper) Total mi per m of component  •_ !Wst_ imj  "i""ujffi 7S3T~ -r  _„ igty_ "3990)  """22T"  ToTfi"Sol  Units lay mi/unit cortv. riif""""T"iT6" """""50] |m3 I 0.33 90 0.78 50 188" 2.00 m m 3.00 116 m 150 m 1.00 150  1 Excavation j IBedding sand i IBacktilling j jJOOrnm die. pvc pipe conduit i 75mm dia. pvc pipe conduit j Incoming electrical service Incoming telephone service Total mj per m of component  Manhole  un  —  mj  mj  mj/kg  mj  ml/kg  mj  . 14  25.00  35  25.00  5 86  25.00 2.50  100 5  45.00 45.00  3000 3000  39 30 23 316 20 427  Wst mj 500 5.00 5.00 5.00 5.00 2.00 2.00  Wst mj 5.00  Wst mj 5.00 5.00 5.00 5.00 5.00  «y 20 00  _  J.  m  3T20  '600 5720 qty. 58 31 41 395j 365 153 153 1196  3150 3150  41 31 24 1046 21 1163  Wst. ia 200 500 100 5.00 508 4.00 347 5.00 299 4.00 777 4,00 875 4.00 329 4.00 198 5.00 214 8.00 36, 5.00 4500 0.00 203" i .bo" 6586  210 105 529 364 311 808 910 342 208 231 38 4500 205 8761  5720  77 77 77 77 77j 77 77  4447 2365 3153 30400 28136 11781 11781  qty  mj 1  qty41 31, 24 332 21 449  Wst m| 39 5.00 30 5.00 zT 5.00 996 5.00 20 5.00 1107  1  3160 m|  182  qty.  81638 mj  119 qty.  138345 m|  7  61324  Appendix 4 :Rood gullies j  i i :mj/unrt xonv. [Units[Qtyr" [no. [' _ 1 00l_ 1 ooo[  j  I Total mj per component  I  Site lighting I ILight standards; iConcrete base j I Rebar""T Steel base plate I Anchor bolts I !HSS shaft 150xV5Q^^ iLight fixture i ;Total mi per component  •r . 1. ! nj/unit !conv. _ !!s_ Jnits iQty. i m l j ~ "' 'Tfot T495j"~  i 1 " " 1 <Q ! j _ _ ji£l 11 ] _ jno. i m | uj ; _ j j  fSite liahtina elec. SUODIV"  1'4.40'i 4"00i Too]  !  I  Sidewalks Excavation 100mm sub base <75mm qravel 100mm base >38mm sand/gravel 100mm concrete (30mpa) ! 150x150mm reinforcing mesh | Total mi per m2 of assembly j  —  .  •  [Concrete curb f" bmpa) ' 200mm base <75mm gravel iTotal mi per m of assembly  Buildina excavation Excavation Excavation Total mjper m3of assembly Backfilling Backfilling Total mi perm:of assembly •t Perimeter drain and dampproofing ]  •  -  m i  i  I j  100mm pvcpjpe Bedding sand j Bituminous asphalt Total mi ber m of assembly  Steel Concrete STRUCTURE All stnirtiiral concrete20rvlPa Below arade horizontal Wall footings (base merrt walls) Rebar' [ Wall footings (east & west stairs Rebar 1 Column footings Rebar Pilaster footings jRebar |_ • Elevator footings Rebar ] Basement slab on grade Rebar i  j mj/kg  >]i  - - !• !rnj_„. 25700"!" 28.00 f 45T00l 28 00!  !  -  j !  ZZIZ.11  iWst. ' ill lOOOi 2.00I Too"! ~! -  ...  o  -  ---  |gv_ 155) "423! i 44"!" 2~84T 735'!' ' "lob! IR042J  4031 5 001 270!" BTobT 700 [ ".00! mn o'jiJot I960!i  6120"  —  -  IWst jmj ......... ._| _ .  j-  -  jmj  "•  1020 i 1020]~ ~ 6 j  T  iWst.. ! mj 55'!'""'"5l0] 29! 5.00! 39| 5.00! 5.00! 348"! 4'ijr— 3351 - 511 ! |  ITij/icg  i  ; [  PA^NGASSEMBUES~ " •"""] .... iParkinq areas j • i 1 Excavation r200mm sub base <75mm gravel M 00mm base >38mm sand/gravel ;64mm asphaftic concrete iAsphalt primer I iTotal mi per m2 of assembly  Omrrfltp eurta  nn-3 m3  "'300!  -•  -  !  6! 25j  "fit '"TI  1mj/unit 1 L^jnv. Ti'ol sol '0.33'! '_90[ 0.78! 50! 116! 3 00! 401 - Tool  •-  [Excavation I 'Bedding sand j• iBackfillina 1 i?5mm dia. pvc pipe conduit j jlncomina electrical service ! ^Total mi oer comoonent  ____  i mj/kg  178  -  -  -  """""T ' 6"33 '4'  "it  ~y_.... _ 31 41 365 ....... 536! t  jmj  -  50!  1 --  -  jmj  _  26781  i . — r  1 Units m3 m3 m3 m3 L  Qty.  mj/unit conv. 0.25 50 0.20 550 • 0.10 300 0.07 1375 1.80" 2.5  Units m'3 m3 m3 m3 kg  Qty. ~*  0.25 o.io 0.10 0.10 1.80  mj/unit  50 550 300 1990 25  kg  conv.  k  9.  mj/kg  ...  mj/kg  m|  mj  !  mj/unit conv. '1990 0.05 001 550  UnKs m3"'" m3  Units  Qty.  m3  mj/unit 1.00  kg  Wst mj .5.00 5.00 5.00 5 00 5.0(f*  Wst.  13 55 30 199 25 322  mj/kg  !~L  ay  m3  90" 22 112  mj  50  Units m m3 m2  Qty-  Units  Qty  m3 kg m3 ' kg m3 "kg m3 Ja m3 kg m3 V  mj/unit too  kg  _  Wsl .  mj  conv.  kg  "~ 585.75 5.22 287.1, 81.73 , ii 72.95r 18.00 j_ 342 3.20 60.8 150.08 7353.87  mj/kg  mj/kg  2334 24857 1 • 586 2334 12183 1 j_ 287 2334j 144078 1 173 T 2334 42012 1 342 2334 7469 . . 1 61 2334 350287 1 7354 1  mj  mj 0.75 25.00 0.75 25.00 0.75 25.00 0.75 25.00 0.75 25.00 0.75 25.00  m  im|  290 "V_  .75021 mj  549  Wst.  188 23 60 271  181914  qty.  mj  Wst  5.08 .5.00 5.00  Wsl  441000 m|  1440 qty-  mj 2.00 4.00 2.00 4.00 2.00 4.00 2.00 4.00 2.00 4.00 2.O0 2.0G  mi  qty.  197 24 63 284  8583  8400  53 53 mj  |mj_ "75  53 53"  5.00 5.00  16643 14644 9138 7178 108058 29324 31509 8550 5602 1520 262715 183847  91" 23 114  qy  J  5.00 5.00  50 50 kg  10.85  mj/kg  50  mj/unit conv. 1.00 188 0 25 90 3.00 20  qty.  13 5B 32 203 26 331  51.....  S.00  50 "50" conv.  mj 5.00 5.00 5 00 2.00 4.00  Wst.  r  Units  13 116 32 94 5 259  -  | mj/kg  conv.  13 110 30 89 5 246  75600 mj  21" 0  qV. 19016 15230 9320 7465 110220 30497 32139 8892 5714 1561 267969 . 187524  mj 177.5 87 16 16 4 1550  59645"  179  Appendix 4  * jGround floor suspended slab r |Slab bands !  i"m3 ""." "f "Tkg[ |m3 1  j^mm slabs | ; 178mm slobs "'i R e b a r ! [East and west stairs siab on grade j s l a b ' s j " " I [ S l a b s ~ | " " P " [Rebar [Subtotal " i  Below-qrade vertical 1 3'asement wails 3ebar ! foundation wail o west stair ; Rebar~"1 -.levator pit and wails to u/s slab Rebar | Columns below basement slab i ReDar i blasters below basement slab I Rebar ! Columns to u/s slab band Rebar Pilasters to u/s slab band Rebar Sub total Above-grade horizontc Uooer floors (4no.) !i 200mm slab bands 24Q0mnT '""'!" ' IRebar j * 228mm"sTebs 1 Rebar !17Bmm slabs \ ! Rebar f 1 iRoof |i"200mm slab bands 2400mm slab bands Rebar 228mm slabs Rebar 178mm slabs Rebar Roof slab to east and west stairs Slab Slab Rebar Sub total Abovehgrade vertical Shear walls Rebar Interior walls to orth stair &washrm. Rebar Elevator shaft Rebar East and west sair walls Rebar f Interior columns upper floors Perimeter columns upper floors Rebar 1 Interior columns roof Perimeter columns roof Rebar. Sub total Misce laneous Landings HarHandings Stair flights Rebar Sub total  J57247ff  __|  6T89'i  E g i  I 2" 9" 65 973 i """'"" "2334"!" " 21 51 "T! __ . 4966521  "i[ "233!4 ""T955I4] "'""T'i  "425841 "i'955'i  2334] 2334! 11  1" 02736 0:: '"" 8T  4.61 j !m3 :m3 ! '"7'02 (kg _ _ l 2"75.77[  [Units;QVToiyicbriv.  0.75!  25.Q0J  ""075'i 251"!  T75I  " 075] 25.001  '_ "276]  jkg  i 24 23 21699! "7  075! '."'SO]  mj/kg_  M"  L  100mm day brick (210x75mm face) Mortar i ! Stainless steel ties j  I 227153"! "7488431 -379939!  •372489! 2.00 "717033] _ _ "106938] """"8876"!"'"""4.00"  __j "1090771  ?3C 8070'i 1786! "'Too """' ""894"! 2.00 7708628]  """"''8231'! 1827 7032 "75J205  15191 •  _  •  -  ..  '750831]  .  .  ""467:- _ 1DL2I _ ] T750205  -  q'iy" " " N "  "(wit ;  " " " i s r i ZIJJLII! 6561.5  > - "i:n| !m3 jim_3 _ jkg • !m3 !kg im3  .  ^ ! •: ] 1 I  !m3 " ,us : i !m3 j jkg_ _}  imj 1 !m31 ikg . ! !m3 ' "jkg '  254.44 ""5T2.86  ~ jm3  p.  '"  !m3 m3 kg  L  1j I i la  conv.  * ""  25.00  mj/kg  m|  m3 m3 kg  454305 .915717 897736 i108552 403553 436343 2Q3324  - 2334 3912.82 1 61.09 2334 1955,04 1  150800 . 301599 8722 365294 - 3913 142584 1955  075 075 25.00 075 25.00 0.75 ,25.00  113100 226200 218052 273971 97821 106939 48876  2.00 2.00 4.00 2.00 4.00 2.00 4.00  .115362 230724 226774 279450 101733 109077 50831  2334 2334, T  25534 522^ 422  0.75 25.00  19150 3921, 10547 5423081  2.00 2.00 4.00  19533 4000 10969 5567993"  2334 2334  8722.08  1  421.89  Qty.  Qty. 150.10 L  94.03 44.30 . 162.90  conv. 2334 1 2334  22140.73 3328.78  1  1568.22  l 5766.42 36.86 24.58 6942.72 9.22 6.14 . 1735.68  m3 kg Units  Qty.  m3 m3 m3 kg  ^  Qty. 19.20 9.60 59.84  kg  2334 1 2334 1 2334 2334 1  2334 2334 1  "conv. L 5752  0.75  mj/kg  350333 . 22141 219466 3329 103396 1568 380209 . 5766 86031 • 57370 6943 21519 14331 1736 kg  h  m| 075 25.00[_ 075 25.00 0.75 25.00 0.75 25.00 0.75 0.75 25.00 0.75 0.75 25.00 h  mj/kg  23341 44813 2334 22406 2334 , 139667 1 5752  Wsf 262750 553518 164600 83220 77547 39206 285156 144161 64523r 43027 173568 16140 10748 43392 1961555  mj 0.75 0.75 075 25.00  |  2.00 4.00 2.00 4.00 2.00 4.00 2.00 4,00L _ 2.00 1 2.80 4.00 2.00 2.00 4.00  ;  13! 16 16 16" 16 495793 m| 6076  1513  .  547  . 112  5567983" qty.  268005 575659 167892 66548 79098 40774 290B60 149927 65814 r 43888 180511 16462 10963 45128 2021528  m| 2.00 2.00 2.00 4.00  22"  1  mj  Wst ; .33610 16805 104750 143800 298964  —  244.5J  qty.  2.00 2.00 4.00 2.00 4.0(1 2.00 4.00  2.24  m3  1 mj  445397 897761 86320B 1086815 388032 427787 135504  10.94  k  Wst.  0.75 0.75 25.00 075 25.00 075 25.00  64,61 129.22  kg m3 kg  234312 1705991 4321" 4656 16284 17547 1036 1692 679 1128 12088 19884 4374 7192 49"5793  1  0.75  34528,32  156.51  m3 kg m3 kg m"3" kg m3 9 m3 tn3 kg  2536" 0.75 25.00 "T.75" 25.00 0.75 25.00 0.75 25.00-j  9  21286. 675 1354 65 887 43 15801 765 5718, 277  11  "2297T8 2.00" "• "Too 423"6' 2.00 Too' 15965 2.00 .16872 4.00 TOO 1627 4.00 665 2".O0 1085 4.00 ii'851 2.00 19120 4.001 4289 . ..2.00 6916 4.00 481872  0.75  2334 593863 "2334 1197015 1 34528 620J36' 2"3"34" 1449087 1 15521.28 15521 • 244.38 2334 670383 " T T 7820"  m3  Units  . __  2334I 1! 2334: li 2334 j ' 1j  276.62  1'Umts"""" iQtyT"~ -Qty  3062911 6562"! 5648:  fj 2334J_  242] "'"T79"0"8" 9.12i 674,88 058 65.09 0.38 ; 43.39 6.77" 764.78  1  Steel -7B54kg/m3  EXT ERIOR ENC LOSURE Exterior wall assembly (framed walls) Brick  : 2.00  m| 408.6 531 .234 428.4 32  32 32 32 2021528  qty. 34282 17141 106845 149552 . 307820  mj  28 . 307820  t  Units no. a No. k  Qty./m2 mj/unit conv. kg 64.00 2.04 32.40 1.8 3.50 0.057  131 0  mj/kg  2.50 45:00  mj  326 58 9  Wst. total mj qty. 10.00 343 5.00 El 5.00 9  1172 1172 1172  mj  401668 71769 11048  Appendix 4 [Nails ! Steel angle | Bolts ,Coiiik fpolyu re thane) ) Backer rod (poiyethvlene to am) jfotai mj per m2 of component j insulation :75mm extruded polystyrene board j Plastic clips (pvc) ! Adhesive ifotal mj per m2 of component | Air barrier (peel and stick) [Rubber based liquid primer iCaulking 1 mm rubberized (at ties asphalt membrane ifotal mj per m2 of component  No. m no. . m m  14.00 0730  10 .0 1 3 0 0.30  Units'' Gty./m2 j mj/unit Iconv. m2" 2.75 no. 3 5m2 "i"  10 .0 " TOO  0702  0  Units " m2  -  Gty./m2 jmj/unit  1 .005 10 old"  m2' rri  18 90 577  [Steer  Units  m2 • im  1m no.  1 Screws jMetai beads i Sealant  conv  3  3 67 23"  45.00  "28750  45Xib  mj/kg  m  QtyVm2  1 mj/u7 n5it  10 .0  imj  18  conv.  jkg  10  mj/unit Iconv. 2750 0 .74 0.56 074 "G\56 "0J4 moo 0.70"0oS 2750' B '7"'  a:  Qty/m2  mj/unit  12 5.7  11 .0 0.30  Qty./m2  0.23 "" '""" :00 _9 0730  2"  "2 "0 ""0 b 0  299..0 0 '2 00  1 B ofpo'ryuretfiane) lts~ ICauik 1 Backer rodm(polyethylene foamjj ITotai mj per 2 of component \  1  I Insulation i?5mm extruded polystyrene board ! Plastic dips (pvc) [Adhesive . jfotai mj per m2 of component i Air barrier (pee and stick) [Rubber based liquid primer jlmm rubberized asphalt membrane ICaulkiiig (at ties) ITotai mj per m2 of component | "'~  50 .0  "29700  i Units !no. ikg 'No."' No. m no. m Im I  mj/kg  o  mj  6 4.00 32.40 ""3750 1  T i oo" 10 .0  "673(3 „  _  3  _ _  j  0.5 6.7  10 .0  conv.  .1.0.0  J"i  60  / '  "  kg"  2.75 0 02  1  "  Qty?m2 mj/unit conv. ffji) _ ... 1765 mT~Z ' m " "0.40 '"57  Ei  Units m2  kg  m2~  2  mj  Wst  131  mj/kg  mj  326 58  2.50  45700  ""0 b i 1! z  f  mj/VQ 31  0 1  "Wst  2  mj  0 0 1  ii  |  100 .:  s'oo"!  -  -  mj/kg  total mj  18 "95"  -  Wst""  96690 5815  imj  66022  1172"! 1172  14789  "" 'T"j"72 T 22" iil'77  ... ......... 2769 ".ZZ.JM  mj.  • 1172 1172  16244 2104  Imj 1172 1172  77352 379 566 """ 648  1172  1172  1172!  "l 172 f"  T927" 2104'  2 2  f  |mj 1478 1478 1473  . 1478J  1478 1478 1478  1478 • 1478  '2 5.00!  !'  1.1  2654 .3119  1478  _ _ 303 5 "T02"  506540 90507  T03897 34918  515  ni|'  1478  448111 7278  1-7534 --  -  UJ  .60 s5 70 o  115  7  qty. 343 611 9 3 70 24 r  Wst "mj 289 "" "5 5.00! 50 .0 97 50 .0 390  97.00 -  qty.  66  100 .  50 .0 50 .0 2 50 .0 2 5 0 .0 490  160750.0 "" b  mj  1172 1172  16  5 0 .00 57 0i  3 67 23  mj"  22T5T fl " '20 '92 2e8 6  71  ...  28.00 45.00  qty.  14  0 50 .0 0 50 .01 1. —g-jjg 50 .0 ""2" 2" '5700  _4 _5.0 _0  ._  -  Units  ill  TJ  50 .0 2 50 .0 15  j  1  ;  ™?.zzi..  kg  2.04 16 . T17 ~790 7.0 "05!  "iUriits""!Qty^rn2 mj/unit jm2 no. 3.50  i" 5700 i 81 " ~ - |  gy  ..........  65  conv.  „  ...........  !Wst. 13  1  mj/unit  Oy t7m2  Wst !mj 5"4 5 0 .000' 12 57 12 5:Q0J  lT'9368  . . .  83 5 ""' 87"  2" 50 .0  ImjAg  355336 5772  1172 i"i"72 ... .. qV  Wst imj: 75 10.0 5 50 .0 "' '80  imj  1  0013! """'"" "ol'I 5.7}  Imj  J5.00  kg  0  mj/kg  0  kg  ] mj/unit conv. 60 "0.26  10 .0  __  conv.  10  Tf"72"  T'l7'2'  ii.  19" 99 2 .........  500  2  1T 72  1172'  ""1"02 5" " , '""1172; 1172 -"4T0  WsT m] 5700  115  i  00m i[1M ortm ar clay brick (210x75mm tace) jStainiess steel ties JNaiis ! Steel angle  iqty. '"303"!  .0 975 "" 50 "5"00 "390 95"  " 0.005  jfotai mj per m2 of component Exterior wall assembly (shear walls) i Brick !  5"b .b  3876 82386 '27689 2104 247""  1172! 1172!  2 " .......2  Wst. ;mj ""289 500  "" 0 67.00 1" -J790 — —  •a'  5" 0 '0 5s0 .'o0 " o  2 2" 490.  |mj 105  3 70 24  50 .0  --  Units ;m2 1i12Screws, mm reinforced gypsum board self tapping, bulge head 25mm no. ITotaf mj per m2 of component studs Units |92mm steel studs m I Steel stud track m [Blocking m no. • i Screws jno. 1 Fasteners iTotai mj per m2 of component {Vapour barrier | Units iPoiyetfryiene sheet im2 •i Sealant m ITotai mj per m2 of component  i12mm gypsum board I'Gwbtape (Gwb compound  05 .  5'"? 67  j Exterior sheathing (Densgold)  [Interior Finish (Gwbj  0 2" 1  0.7 0.0 95 7  180  ""T9" - JJ  ... _ _  2 121  EL  "27934  .... ........._ 3538  1478  ]  Windows and entry doors j Glazing | Glass layer f [Total mi per m2 of component  m ' m32  QV"ym2  mj/unit conv. 300  10 .0 1 no  _ .  mj/kg  mj  300 300! '600!  Wst  m|  50 .0 50 .0  315 315 .......  qty.  mj  1072  '""175360  181  Appendix 4 Frame  !Gty/m  lAiuminum frame ! Spacer' ! Fasteners I • Glazing tape iTotal m| per m of component  "iibifl  ; kg  S" .'oo7  I mj/kg :mj |Wst jmj "2'i274":4'ajjj5l0'i f"!235!118!Slob"] Oi 45.00! li 5.00!  i i 1 0 : " l O ! i  C'l.-ii^riinn head section  IOty/m  IDeilection head section •Total mj per m oi componeni I Window hardware  imj/unit icony^ _[kg_  lAiuminum door hardware  :Qy  |Per door J_ _ iTotal mj per component  imj/kg  „J j_ m  |mj  IWst, • |mj 250 rooi '250  _ imj/unit__jcony _ _ikg  imj/kg  \ L_  Wst _imj__ 'T.D0!  75'oi  m  ..ifW: 503 ............. i" if "638  2787!  575 S8t ""5 '"75 qty. 253 ""253" qty^  L  "'"' T~"  im|  :i  1779060  m  569!  m  327403 _  im) 4j  3030|  1551!  1117104  |  JGranuiar finish SBS top sheet iSBS base sheet jAsphaffTSy^ iTotai mj per m2 of component  IUnits 'l'm'2 !m2""""'  ilnsulatlon  !Qty/m2 jmj/unit :conv. i 1.20 ( 318: I ;'1J ""248] 12761"2.5"!""  IWstmj'"' 382 TOO" """_' '"298"' TOO 7" "Too  j mj/kg  Q1y/m2_ jmj/unit iconv. I kg J^^bS J T.qo; ^ |5' | ' ^ 5!" 29.70!" isol "T"6161]""""oj 45161" T"l0'r_ "' j_~ _ - 35]—- • jj - 29.70]" 3.50'f " j ""] "T05"j " Of"45l0!" r  ! 75mm rigid fibregloss board _ i !m2 iscrews and stress plates |_ JnOL_ iTapered fibregiass crickets 50mm ave. Tm2 ' • Screws and stress piates j • Total m| per m2 of component i j Vapour retarder IMembrane^ jAsphaJt. jPrimer ; I jTofaj mj per mi? of component [ ITotal mj pBr m2 of assembly I •!  ' iWst. Imj '"'548']'" _TooT ''"548!""]  • Imj/kg  '!"Tool  Root assembly [ I Membrane  ""608:T  Ikg  • Qty. • jmj/unit Iconv. 1 r o o f S o l : "  iPer operable window JTotai mj per component  • Parapet  imj/unit iconv.  :Units_ ' ImP" 1kg"""" !m2  4  Qt"~AT1iT.07 mj/unit iconv__ I kg ""'070'~~~ioot_~__ 18  i"  J mj/kg _!m) I __ ""' P  IWst jmj 160! __5.00 ~8["""_ JW lb7T_ 5.00 """IT. Too ""283"! IWst, T07T" ""500  " r " 1 2 !  " '"""'0 .0  jgv. _401 ! " 3i2 r  _H2! _. 81" _ " " ' i 297!"1'5'5'ft"'460961'  J.9V„  112!  133!  !  IUnits ; Flashing and counter-flashing (18ga) "!m2""' • Membrane ; "!fh2"'7' • 12mm plywood blocking • "im'2" ; 11 mm Aspnalt impregnated fibreboard. ] _ _ . :38x89mm cant and blocking : !m : Vapour retarder membrane'__: 1'm2 iTotal mj p_er_m of£pmpo_nent^ |Roof access hatch ! Hatch !Total mj per component  Qty./m2 imj/unit • Iconv. [kg o"75":"'!"'"3l'7| 1.20! lOO.Obi • \ blS'b'i"""""67'f""'."I" Pol~20"!P'7 Too!" f'slT""I 0.601 100.00!  Qty__  nj/Uhrt  !Qty/m2  mj/unit  conv.  jkg  I mj/kg !mj 'Tj"25"!"  IWst. 591"TOO 120! 5.00 "Too 5.00  62! 726]  1551!  206419  ...M.....1...-.  210! •  72156  mj/kg  INTERIOR ENCLOSURE  Ceiiing asse_mbiies_ I ! Acousfic tile and t-bar  il 200x600mm tile jT-bar_ j . ! f_2g as u spens ion wire (§ 600mm be • Fasteners ! j .iTotal mj per m2 of component  Units  i mj/kg 0.75! """0.11"  !Qty./m2 .. mj/unit iconv. • IUnits 9 j L ! ! 12mm gypsum board ! 601 " "iTb'b' iGwbfape I ! Im ! f.ib 0.281 !Gwb compound ! ikg ! 0 23 2! |no. ! 9.00 | . 0.0013 • Screws i • ! ' 0.52! ' | 2.25 !m 1 2 1 mm furring channels ©600 oci " """!"""675! jm "1 225 "!38mm cfianneis® 60b be 1 ! 12ga suspension wire @ 600mm oc !m • ! 0.1! • no. i 0.006 jFasteners j j | 2.00! 1.80 im 1 0 " "8 iMetaibeads ] 1 j 0.30 f |m ISeaiant ! !_ " I " 5 1 6 1 "'"""5'7r k  1  2!_ __30.00^ '""Oj 29"b0'i  [mj/kg_ • m| ! ! !. 0! 45.00! 29.00! 1  "O 2jP  ILZ_ 0;  T9.06T  29 00!  45.001 2T6oP  J85281 "41698  6S |_ 5.00! " 6j "Twr  6847 ' 68"4'7  IWst mj 601 10 of 5.00" 0! 5.00 1 ! 5.00 34! 5.00 "49"! Too TT 5.00 5.00 21- fob .6" .JIEZ "56  I qty. ..™......J£!i.. —T§78 3331 66| ' 333! ~ 1 0 8 '""""'" 0! 333! 161 01 •1! 333 i 184 3 3 3 1 36! 1 1 8 64 3J3I  L  2  5 i  5! 333! 1825 • 3331. 1j 189 " ' " ' "_ "548 3 3 3 j " .... . 2] " ." ' 2"j"" ..... -yjjj—  Appendix 4  182  iTotai mj per m2 ot component •  153  |  interior partition, no rating „.:,:.inm nan [Partition to u/s ceiling I ! 12mm gypsum board j jGwbtape | [Gwb compound i | Screws -[ • jMetai beads I |See ••' i.^mm steel studs © 400mm oc j i1s TFasteners/screws eeTstud'track['"~ZZ11 j64mm acoustic insulation \ iOOmm rubber base 1 lAdhesive i  i mj/unit i . . -.  (Unit's1 Qty/m2  :• m 20 0 ; mT " ' " 1 | 6:2?! Z Z I i ino. E ^ Z Z Z Z i | —".-22J0I ""7""57"46"i r z z c i _ _ _ _ _ im o M I " 57]""""' 0.18 ;m "T7501  ZZ.  |rn Im |no. ' im2 jm  60!  _ _  "' •""2751  ! I  "7BTTTI  27061  i i  T074] .06I  I™?1  0:07]  ; mj/kg  kgZZZ  0.63  Imj  Imj 10! 5161 T .... _ _ j .„ 57651 3 5.00! 9 57661 50 5 00! 14 5:001 '"7" 17 Slo'l 9" 5"65i '""5" 5766] 120'  6mm qvpsum board I iGwb tape . 1 iGwta compound | Screws 25mm ; I (Screws 41 mm | ! jMetai beads j (Sealant ! i :64mm steei studs ® 400mm oc j iSteel stud track; i 164mm acoustic insulation 00mm rubber base j Adhesive I  I I I  Wst.  " 0|b i  '45.06" 29.00  "2+ 0!  "29760* 29.00  6 "076 0'bT  Tj  4T60 ........  "075  "0"  ..........  ST  TOO!  237! j ' ; mj/unit conv. iaZZZ 1 Units " Qty':/m2 I 400' """80" |m 2.20 0.28* 592' 2 Ino. | 0.0013 0.002 jno. 22.00 jm "OH |m IT im 275" """0.6'3'i jm 0T9~ 0.63 sno. 0.0061 \m2~" 076! Wi jm Oi'07 . 075 T'TTi^^ZZZZ i  Furrine .•I IColumn furring I \ ' r " ~ " " ' | ' 1 2mm qypsum board f_wb tape i I "~ "IGwb compound | Screws • i |Metal beads ] iSealant : I l64mm steel studs O 400mm oc i 1 Steel stud track: i |21 mm furring channels @ 600mm oc ! Fasteners ! i 100mm rubber base I j Adhesive j  320  0  45.00 45.00 "29.00  0  oW '""iTsb  T  2T0B" Ob  "6""0 "i"  j  Wst.  0  10!  "T  Imj  "5.00  9 "50  T5.00 oo" " T 5.00 oo  """"i"7"9 " 5  97.00  -  Ob"  ffbbb"!  ! 0  "b "3  " 26  ...... 0  mi  5.00,  60  45.00  .........  29.00  .........  '29 00  6 """'""82 14i 601  45.00!  to  5.00 5.00 5.00 ....... ......  97.00  -  .......  .  .66  qty-  mj  826 826" 826 826 8261 _ 826 826! 826 826 826! 826! 826  T2  "'""86 14 63  500  6621 4478 1041(3  :  ?  " 4  60 143" ! ' 5 75.00 . 3! 5.00  5252  .........  ......5.8?  1 2 ... . .  5.00  ........  _ .  mj  ""5700  "205920 378 1130 791 1216  585 '585 "5"85"  TT T "o 5 ........  2! 1 "2"  M  585 585 585 585 "585" "585" 585 --.  1l" 8"  ""Too" "Z J T o b  1  . _ .L  '" ' "3" 9 "" '5"3'  5765'  Wst.  3202 "4480 3315 j • 10902 29760 " " 33151 """" "74882" 33151 47059 T3"j'5'l 25375 3"315" 58992 "•32970 33"i"5 3315' ZZjZZIf  1 2 1 2  7___ mj/Vg  '4375§b  ... _ _  igv... 352  437  "''[Units Q'VAri'f" mj/unit conv. kg 1.00 jm2 60 j Im 1.10 0.28J !'kg"~~'"" 0.23 2 [no. _ 9.00 0.00131. Im ""019 jm 0.75 _ 5.7 jm ' "450" 0.63! jm .'074 •"'.631 |m 400 o:s2'|: jno. 1400 im 0.37 12.8 0.75! 0.04 |m2 •  i imj  255.  " T T 7" ""-'5766"  .........  -  al  18  5.00 5.00  1  3315! 3315!  33T5I  9""'"'63!  10.00  2 ...  "........ 2906"  "T; l . l^  j  1 2  IZZil^ZZZZ]  iTotai mj per m2 of component \  imj  ___L  IZZZELZIZZ]  '" T 2 T  jqty. 132! '"" TI  """"'"•'i"  i Total mj per m2 at component | Interior partition. 2nr. rating. 3400mm nign ' [Partition to u/s floor I  164;  - j  14 2  54516 1197  ...........  457 "" 1358 5594 '71305 11726 52316 3278 11422 2208  !  2481  ff otai mj per m2 of component  "263 !  Wall furring  Units !Qty/m2 mj/unit conv. *kg mj/kg m| *Wst mj .jmZ 1.00 60 60 j 10.00 0 ' : 10 [m 5.00 0[ 5.00 0.23 2" ZZZiaZZZ IiG co jno. '" 9.00 0.0013 45.001 Sw crbew smpound '_! J "TT" "'5500 ""o"o ..... 2 jm 29.00 ; Metal beads j ZZZIll iSealant | _.]..;..,.. im _ _ b .... "4.00 |m "'"900 60! '"5'76' 5.00! J21 mm furring channels @ 600mm oc 5:52"! 4 0! ! Fasteners i I jno. 1 4 Ul) ' 0.006 45.00! 5.00 : 5 iOOmrn rubber base | m :b.3'7" ZZJCf 5.001 0! lAdhesive' T ""'"~m2 ""'"075" 97.00 3 • 5.00 '"'6.04 ! \ I • jTotal mj per m2 of component j ! 139 i_ I - i I Doors assemblies I I "" Solid core non rated (2100x900mm) ~~ " | Units Qty mj/unit conv. jkg • mj/kg mj Wst • m| 1.00 iDoor""~"'"] """"'}""" [no. 200 1.00 18aa messed metal"frame ' I ]m 5.20 3.13! 16 29.00 472 ..... 600 '45.00 """68 O'si" •jFrame anchors I j |no. ..... ....... ........ 0.4 ! [no. 300 "'"54 ! no. ""2! '60.00 "'"'90 """T766 llockset - I TT06 ~w~ '2TI no. 50.00! Closer ! " 0 4 ] : " " "0!" 1.0b : ino. "45.00T ""18 1766 "Additional S t sotudsp l I | jm 540 0.63"! 3 29.001 " 99 5.00! ! ' Less 2 sq m of non'rated partition 2.001"" ' -237 -4741 ' 5.00 ! ifotal mj per component I • 658| 1 i ' Steel Ihr. rated (2100x900mm) 1 ! Units mj/unit "conv. kg mj/kg imj iWst Qty. Door no. 1.00! 400 400! 1.00 12mm gypsum board Gwb tape  j I  "OS  j  o!  """"Oo  [  """"T'.'bb " " " 2 6 b  —job"  ilb " • " " O o i  il "  :  qty-  66 0  .....  " "6"  _  900 900! _ 900 900!  T  ... . . . . 4  •  imj 900  63! 4! 5 3  !  2477! 02  "4040  !  m|  qty.  145 145  13181 19331 2636  ""T"4"5 145! .._!„4S  15  29290 69125 9885  ""796S  ..............  91 1331 18 • 104! -498 650  1572 4476 •'"" "2406  !  145 145 145  ""55  ........  900 900!  fy  68  404  498  ""i"48'6  ""-' 9'9006'j 0  148!  59400 "'"291  "'""-'7"i"5'62T 2188 mj  6060  183  Appendix 4  11 8ga pressed metal frame Frame anchors j t •Panic set ;Ctoser  : s>Dp  | |  Trnir.  . IZI  •.Additional studs :Less 2 sq m oi 1 hr. rated partition ITotal mj per component j "[Pair solid  im ino. Inc. !no. Ino. ino. im  1  5.201  3.13i  !3.00[  '"'ol'' 5"! "2.2! "SI! 074"!  :  iToTai mj per component ;Garage door and opener  mj/unit ;conv. ikg 1 no!  "Door"""" ! • Opener j iTotal mj per componeni Stair assemblies "": Stair flight ecce_ss_ories_ iStair nosings I iGuard rail 40mm steei tube jVertcal supports 40mm steel tube !Fixing piatesjand sjuds ______ IHand rail 40mm steel tube _ I Brackets j !Tota! mj per stait flight  !  ! Stair ianding accessories  iUnits [Qty. ij/unit im I ie.oo im "'"'• TOO !m r"Too ino. " i T o o jm 1 3.90 ino. '""]'""""Too" 'i'm2" ""']2:36  !  iResiliant flooring^ i 3.2mm LinoJe_urn_ iAdhesive I jTotalmj per_m2 of component  Units_ m"2" _ ]m2 [m2_  1  !  iGranitetiie ! i jThin-sef adhesive i iTotaimj per m2 of component ! iRubberbase j 100mm rubber base JAdiiesive iTotal mj per m of component_ iCeramic waiifiie  "TTT!" -—jr-  7274]  " 075!"'  iUnits  6.811 ""' '""101  ilo'l ilb] 5161 "5l'b! !  477! 68! 55; 303! 133! 18! .: """" -9"i"8? 661 i  Imj l.bb 1525040! "Too  lib" ill 116" ilb 116 '""ill Too ' T i l t _T5o 500 1321 | 68!" 734 j""' 561!" 561' 51"] '!" _ _246...  15! is! i'5"! i'5"! 151 i'5"'! '•'i'5"! "i'5!  10} i16' o!"'"  1212! 5'5l! 66?" i 361" 56'6'i" 57"!" 92" i" 249"!"  '""ilf i il!  \ 45! " 122!"' 7836"'!" 1269!  70l 5.00] 761] 5 00i i'bi '5':6or ! . 187!  73! ""713:"" ""76! 197| . .  64001 64'6"6": MM! J  IWst imj Tool  . i.3V„..  12120  5592 '682 1 357"! 5656' 566 923"  —  ill jit: 10[_ Tpj_ ' 76 f ""75]  T ' 749T  7151 1023 8i"8 4545 2000 273 " i82 '"5 '" -i'3773  —  "452 _"""l2i_7 -18384  iWst. imj "7086'i"ilb]  ""2460]70 .01 '"'9480'!"i  ""i'iT"TSTooT" '"""8"!"""28.00 i '"" _ 280 .0 11! """It  45:60  !mj/kg_  imj  12T2Too!  "If"28"VO0"! ""4]"""Islb'i  m i2 ]m2  !' ""'"'  JQty./_m2 ! mj/unit _ jconv. 1.001 J_ _0.87i T611"""_""" j "'" " 1 i'b! "756!"'"'"1 "'"17!"  ;Qty/m2  Imj/kg 1i 80! "11 80.001 Of 97.00? [ i | mj/kg  !QV-/m2_ Imj/unit iconv.  Tm27Z 1m2 "'• "1"~"Tob|  ; Ceramic tile flooring iCeramictile _ | iThm-set adhesive iToial mj p er_m2 oi'component  29.00! 45.00: "sTooi '5616'!" ""silo! 29 001' "pM!" _5'6W 29lbT"  1.001 ilb] ilo'l Oo!  "T ~2iqr~ T z2 r !  jNylon face t87kg/m2)_ _ J !Pok]|propy!ene backing (1."35kg7m2) IAdhesive I ! iTotal mj per m2 of component 1  45T00! 2110!  472 i 68! 541 3"bo '"! 132'! 18"! i'i'6"! ~TJ7Ti~ 685!  ikg imj/kg _Jmj 1 _ ! "'" "'274j "'"' 27 .41 "' "TS! 30T21161  ! _ 216'!"""""12:74]""  !  FINISHES !Carpet_  iconv.  60.00!  mj/kg ; mj blob! 11 40!BOVBB'I  jQ_ty/m2 Imj/unit Jconv_ ikg " i""Tlb]"" ""'"f ' 2741"  (Guardrail 40mm steeftube 1 IVerticai supports 40mm steel tube (Fixing piates and studs i  :Granite file flooring  2:  ""io]'  2I6T "'""]'""2I0T  : Additional studs 92mm  29.00! 451b] 45.00'! 6'oMj  [n]/kg  !> Unit's" i'QtyV !rnj/unrt iconv. no jfb'O'j" ZZ1WZZZZ. m 6"Tb]' Til! no !Off? 0T5'T no. !6"M] o"T[ no. !216"'!' 5"! no irooi' T'f m ill' !2"Tb]' no T TT no. o'Ti" m ! 5.40! 074! "ml ""'"]'"Too? ^37';  :Door ji 1figapressed met'ai frame " - Frame anchors | Buttsi Panic sets ; iCoordinator 1 ^Astragal (sleeij j ! Closer  iTotaimj per landing  16! 2"! vi 5! 2"! 0"! Ti  02 .5;  sTod * ITOOT iLGO'V ! i oo T  W"  5 7 6 0  :  : i_  | mj/kg  mj/unit  467712 - ;, "6'5"i"84  971  7 4"7"T~ iUnits  1'rrT  "im2 "'"  (Units __  !Qty7m2 imj/unit iconv. ! 1.00! 3'6'i~" _p_ j -.  kg  !Qty_/m2^ iiTi^ '! iconv. -1 J28r"""' J  kg  !Qty:/m2 imj/unit  kg  n  "7"'tm'""''~j3_Z0?ii„ iUnits  imj/kg  :m(  it"97lb'i  IWst. '""3'b'i"75.00 ""9"7"i 5-00 "i'27"i"  iHiir^? „ ! L 1! 971b"i M  |mi/kq  Imj  Wst.  imj  iqty32 i  102 "T33"  im| __l2ll i'2"6T "  3780 "" i2"22"2  Appendix 4 !m2  ; Ceramic die Thinse; adhesive 2 ot component ! iTotai mj per m I Paint :Gwb ceiling iGwb exterior wall framed iNorrroted partition iRated partition i i Column turring ;Wall furring  1 00!  im2""-'"  Too]  50:  Ti : ]  '.ZZ'Wsl  184  50! 5.00! 73] """Tiooj  97:0fj]  T"23i'  53! •f,  545!  28613 4l"63T  Z~_§;  IZZZMI  |  i  'Units Tm2" jm2 im2 ]m2 m2 !m2  Qty/m2 ;mt/unit  [Units ino. !no. ino. ino. ino.  Qty'.'.'  conv  3.00!  10!  3.00  10! 10] 10! 10! 10!  6.00] 6.00 3.00! 3.00:  |kg  _  mj/kg  |  • ;mj  #st7i m 30! T'obl 30 j 1.001 60; 1.001 60J ' 1.00] 30] 1.00!  i  301  i  1.00  !  qV 3b| 301 61 | 61! 30 30  :  mj '""3"33: 1172 3315 585 326 900  10090' 35512 200889 35451 25028 27270  Washroom accessories 'Electric dryer j jToilet paper holder iSoap dispenser . IGrob bars jfoiiet partitions and doors •'Total  mj/unit conv. kg. 5" 1.00" ............ TT " 1 " ' .... ... Too' ""'""3 ......... TOO'  mj/kg  !mj  5"  2"  1 3  L.  !Wst. imj 400! 1.00 90; Too 60" 1.00! 135, 1.00 Too" 1.00)  80.00!  .........  60.00! 45.00  ...  I qty 404 61 136 404  Imj 20 8080 30 '''2727 30 1818 2727 '"20 ... . "_ . ""30'  MECHANICAL  Mechanical take-off based on Jack Davis buildg, in numbers and size of components are pro-rated for study building based on floor area. Waste hasseen included innitial take-off '  -  jAuto control valves [150 mm 175 mm [Total ~izzzi • IPumps  'TNOT" "  "'[No" '_ '_  " Ts  ifotal  •-.  3.75! "JNo. INo. 2.251 "TEi'i TNo77" "7". 7 TS'i'"'""'1NO7'"'" "6135"!'" TNO7 0.25! INo. ' I 0.151 iNo. . | I "]NO7  I Air compressor!  "(No7  b:  194 133 133  j T  ""2T  77 55l""" • 55_, 55 55  ""'"to" 1  2 I.  -  .......  -  INo.  iVAVb'ox'es  1  Ifotal fans  - --  i  [Expansion tanks  !  1 Rot water tanks! .  j  INo. "(NO7 """"  ... !  ; mal silencers j '1co_iinalowe7 " ..... iCriillersTOOton!  _ .. |. . ___, 6.95 i  ZD5ZZZZ  :  j1. Air handling units 11.25kW i Ducting IDuct hangers irods  T 1374  i  lUnits l'No7  1NO7  " "•" i  |  i•  "" " 2573  28.50  L  ;  . i  39764 -  """""55 '""'55  165  2 " "2"  300  51.60  15480  1.84  8395  '-"gQ-j  _JO0  5T.60"  15480  1.84  8395  mj/kg • 1  i  ^  37590 ........  k  mj •  7  "  """"420  51.60! 3000  ' T "oT?!  T.8'4i.  47 199001 T'6464! 36411  21672  1.84  11753  1.84  83948  51.60  154800  """2'8'bOi  5!.60i  " i4""4"48"b! T'84  "272BT"  ~TTT28  _  "" 39764  297b b i T 0 9 0 T T 6 "" '""7" 'T78 '4 "29700!"'"•79054 T"" .84  133783 70572  7 0 5 7 2  '" 86"""T.84 T784 36696 30360! 1.84  3000!  ""'3'7'59'or  5154 --  76.40 10161 1.84 5510i • ........... "50806 ........ ' 27552 .......... "'"T7648 .....^ '95711 76 40 134464! 1.84 ^' "72920 .......... 12606 ........ " 6 8 3 6 ! ........ 4202 72279!" .g 4 76740" ""4202" 1.84 2279! ........ ..... ......... 1.84 6836 133783  150  "'""1  i  ........  """ "8038  h  "2 '"3"T"  '""T'760" 165"  1  —  -  5154j  130135  .... ^  —  11128!  51.60"  mi/unit conv. _. "'""T" •7^—T76I " 3b '."l"76  31364  E El E ZZJ§!  1.84  2522  " M \  ikg • !m  mj/kg  ].B4 ._  8038  2522  j"'"'~ *T  !NO.  9504 28.50  r  ...  T'7'6"!."7  "lNo7"  ZZllI  20520  "720  133 "'"'"665  'i"" . 84" 8 0 3 8  ..........  1  792  [...„...._. ......j  „ _  ZZZyij?!  76740  "lUnits joty" mj/unit conv. "7No7 _ _ . 1 133 "'""5 . ........ 375! "TN_7"'•" "'"'""7"7" TKi_7 "" !"" '"3" IZ1ZZ '.7251 "55 ___. _ TNOI ........ "'"55 o i l 7 " "!'NO. S ............. .......... 55 TNOT"' | 1 ."55 iNo. 0 . 2 1 55" I 3 "iNa 0.1 j  1H e at exch an q e r 5.2 L7s  Sue  "~ "244"14  -  1  .........  ........  "ikW  —  -  """T'5b"24" 1.84 9390 """7'"""2"44T'4  76 40 14822 1.84 8038 76.40 10161" l"84 55'TO' ........ Tbi'eT" T'7'84 5510! 76.40 5883! 1-04 3190 "76740 4202 1.84 """22"7'9 "76.40""42"02 "'"'"' T.84 2279 i 76.40 4202 1.84, 22791 76.40 ' 4202 i.84 2279! 31364!  i"  12  "iNol  :  "i  ........  JDiffusers  • Silencers  "27704' 17315  -  jWater pump  |  "TTbJbbT  "76.40" 76.40  _____  "JEW  r I  IFans :" " "  1  363 227 -  7.5!  . [Air fillers  —  ----- ! kg ! mj/unit conv. imj/kg '" imj" 2 15000 ,30000 51.60 1548000 '"""T".'84 839479  lUnits  HVAC [Boilers  78351i ............. 428711  "~  8395 . 8395  '"'3641T  .;—  ;  1T753 83948  t  ~  ,78351"  Appendix 4 i straps iDudinsuiation I i-ii^i ducting  !m  1900!  1  1.5j  176  !m2  2850  185 29.00  82650!  1:64  -  -  -  44821 I 711063"! T.8992'1'!  ""il'84  T3TT2B0]  --!  "'TW992T  ~-i  ifotarHVACj pDJr.e.'t'-  ICopper piping ]Size  iTotai valves iBrass  [Total  iUnits !m Im im im !m :m !m  ill 251 32] ""50! ...._„ Tool J50j  :"  Umts  T  :  iSi;e[mm]  _ L  Qty.'" ...... nit/untt  conv.  m|/kg '•'"Wo 1739" " 4676 2'!'7"2"67" ........ '5"!i"405' "72 fl.5"2"2'0"""345" T4.9" 209 TT728 ""JO ilT62'2"!  ........... 2092: .......... i'T ....... i'T IQty  Tal irlio" 23! iNo. "32! ...... "'"50!" " I N o " !  m|/unit  conv.  ...........  mj/kg.  §"  bl'25" 0.65 1.37 5.24  45  32 0 0 236 236  ;  1.84"  536418:  318"0l"4"  313014  a. _J  --  75  J7685;  L84  9591  9591  —  IPIumbing tixtures iWC ; unal (wall hung) [Lov. ] I Janitors sink iDrinkingtountain ITotai  [Units ino. ino. Ino. Ino.' Ino.  i "'"I I  mj/unit  "Too  ............  ......... ........ 1.00  conv.  40 25" 20" ""'"'"""30 20  .9.  mj/unit  [Units'iOt)/"]  ABS/PVC p i p i n g J " " ™ " , i  ' IQty.  |size[mm]  32 75 too 150'  Im Im im  20  K ... 507! 1423! • 2459 "4406  '_!6"6 2.94 4.47  "ZZll°§LZZZZZZZZZ iTotai piumbing I TUnits  • |size[mm)  : ITotai  i  18 25 "" '"32" 50 "" '•"75" ""Too" "J50  m  im ;m  im im [Units '[No!  valves iSteei i i  [Units'"'  p f _ | Pipe hangers  !"'  75 Too ........  i  ITotai fire protection  mj/unit  Qty. "T"  "T553T7  ZZlll  T.53T7  ....  conv.  0 960 0 428" ......... 40 """76  im i  Main sprinkler vatve ;  isize[mm]  _..  |m  6S!po T"  -  ZZ Steel (Sprinklers) rmrpiping PROII CIION  M J  - j  .........  "40 246 484 " 550"  ;m  mj/Kg jmj |Wst. |mj iqty. Imj 40 29.40 1176 1.00 1188 30 35633 25 ........ ""735" ilbo To" .'424 '"20 ....... """" '""588" "Too .... 30 ......... "" """3"b 2..40 •182 ... ....^ 89f 5" - - •• "2'9"!'40" 588" Too' ... _""""" "J " _ 2969 ... . . " " - -  ..  .  , i m  0 "" "2400  ... -  5.44 TT'29 16.08"  "'"""2"8!'2'7  mj/unit conv. . 35001 •  imj/unit  23208! 49.6|r 643 ... ..... 12488 [_  jkg  mj/kg  conv.  7 .........  'l'5'li'T  iUnits INo.  Qty. mj/unit L iooo  conv.  lUnits • No.  Qty.  conv. kg *" . 140.6"  IUnits INo. '""i'Nb!  Qty-  61  13 25 0.87!  0.88  106! ' "'"" "645! 2659 3409!  ha.  «950T ZZXII  . .i. m  *.a.  INo! iNo! "'"[No!""  221  40.00!  3'50'b  ...  ........  IbTb  ~~ma  ""'"""3"5'0b  ZZZZZZ  Ti.  m, . . . . mj/kg 880 25.00  .........  """204569  1.84  110938!  110938  22000  1.84  11931  11931  84360 ' T52  55354  . 55354  ELECTRICAL !  Service and distribution . iTransformer' I I30KVA iPnnel boards I . I , I22950W i :24500W " [T Tb'bbw"" ""]"S_'6'TbbW'" Ij""[SoiSv ; R b o b w " iTotai paneTboards  -  ICabie tray I :500mm . I Conduit : i]T'2mm"'" ' | ; 25mm ! i 3 2 m m "I ITobmm" i " " " ! ' " " " " IVerticol risers I  """"""'ITib!""'  [No. INo!" IUnits -im  Qty.  Im |m Im  im \  I  10  mj/unit mj/unit  1 "T • 11 . _ 8 8  1456  mj/unit  8935! ........ 235"f"" 240  conv.  1406  mj/kg mj/kg  J_L  83.9 '83.91'"  84! 84 231 . 83'!9T"'" ""6'7'Ti ""227]""" "132 22l7"p'"_"Z.M  •  conv. kg mj/kg F i'5 21840 •  : b!F9 i 1.73! !2l23! ! 9.5"! l" I  7952! ' .287'!"" 5"24 2280  100  mj  .............  22.71  :  mj  60.00  100 Too "fob fob1  8390 8390 "" '_ ' "2"70  67120! """18160] 18160 122490  mj 30r '6SS200 30: . 30l 3b"i 30! I  1.52!  "'" 80374  • 1  !  • 1 52  " '23856S" T"5"2 158606 il'5"2 15722 ll52 .......... 1.52 I  I  •!  80374  Appendix 4 [Conduit \  ;50mm  I \  :Toloi cable tray/conduit. [Electrical boxes [Wiring  " "  7  pertixt/rec  2-#!2"! -#3 ! 3*7lTSfl'cabie":  - i i s  [Vertical riser [Wiring . :#3 Total seivice and distribution  Lightin3 and power i -ilb luminaries iFixture .amps Ballasts Fixture 1.5x5 V .amps- 3 per 3aTiasiTJ~~ [Compact fi. -ixture _amps • ;xit tights -ixture .amps lEmeraencv rFixture .amps •Totallighting i Receptacles  Duplex Tei/computer  I Switches ITotal liqhtinq and power CONVEYANCE Elevator f2'pe7san'2^  7Q0T i'68l  im im Jnits No"  C i t y : mj/unit r,.ijiz!i JV  Jnits m m ~  ivn.A.int 45oT 75! 851 528001  m m  Units No. ~jNoT ~ ""INo" iNo. [No! [No. INo. ~{No.  No. No. No.  [Units iNo" iNo  conv, §L ZZZM?.  " '"""30"i  ZM .i*9...  75600! 7"5"2"! 478801... T.52I 1259972"] 752'i |  945!  30]  imj mj/kg §L. 87" 45"! 7601 '"'"0.77 160! "'""13: 160: 0.15 13! "ToTs r 7 6o i ZZIS  conv.  •-  |mj conv. ikg ! mj/kg 7'0'i" """3i5"i T26":"" oJf 25 o Z» 2 '"5"2"0 1" """"36" • 70 959700 io 13710 70' 143955 0"5" 2057' 70 95970 i" 1371 "70 275' 19250 -'2.5 70" 55" 3850' Ol "70" 2.5 150 70 10500 0.5" ... _ 70 2100 3.5 j "" "'140 "" '"70 960p_ 1400 0.5! 20 70 '7257890  mj/unit  128031"z z z z z " ' i z r i . ? M  195720"  -  o  imj/unit Iconv §L 1433! i 0.25 250":!6725" 478"i"""""""•" 0.25  Qty.  28335"  7200": 2040"' "2040"  mj/unit Qty. '.'36" 3l: 36! 1371' 4113 1371' 110 "i"i"o" 60 60 '"'""7o ' 4 0 Qty.  826754  28335"!  ZZZ1I?  ;  •  "'"826754]  m  ZZZIIMi  \No~  Units'"  2520"! ZiMi!  186  conv.  imj/kg Imj 358 [ 33.00! 63'i Il'o'o] 720": "noo]  •  "7"2"5"789"0"  11822 2063' 3944 17828  17828  : mj/kg  ......: Car (mass from Otis 2200lbs) IControls, lighting etc. I Door assembly x 6 (estimate) Guide rails 2x10 ko/m 25m Hydraulic equipment (pump) j j Hydraulic lines (steel pipe) ] j Hydraulic piston 20m (215mm die. 15mm thickness) Piston casino Controls (electronics, wirinq, pneumatic etc) f otai eievators TOTAL EXCLUDING CONSTRUCTION ENERGY  i  i  !  1  CONSTRUCTION ENERGY 1'/. General requirements. Construction energy etc.  T O T A L INITIAL E M B O D I E D E N E R G Y G J INITIAL E M B O D I E D E N E R G Y P E R M 2  i  950 50 550 500 200 250 750 1000 10  -  60 100 60 30 45 35 35 35 100  57000 5000 33000! 15000 9000 8750 26250 35000 1000 i90000  —  1.00  .  190000  —  -  -  2  380000  30161400 30767400  . 2111298 32272698 32.273 4.03  187  Appendix § FORMULAE TO CALCULATE LIFE-CYCLE ENERGY OF A COMPONENT OR MATERIAL Let X= initial embodied energy inc. waste current building age T= r= component replacement interval %r = replacement percentage m= component maintenance interval %m = maintenance percentage IF = technology change factor int = reduces the value down to the nearest integer  MJ yr. %  yr.  %  no.  r is assumed to be a multiple of m maintenance is considered to be replacement of a percentage of the original component The technology change factor takes into account the change in energy intensity of materials over time as a result of improvements in technology, scarcity of resources, substitution of materials etc. R = additional embodied energy resulting from replacement of component R = (int (T/r)* (X/100)*%r) Example: 40 year building, (T), 8000MJ component, (X) 12 year replacement interval, 50% replacement (%r) R = int (40/12) * (8000/100)*50) = int ( 3.33) * 4000 = 3* 4000 = 12000MJ M = additional embodied energy resulting from maintenance of component M = (int (T/m) - (int (T/r)) * (X/100 * %) Note: as the replacement interval is a multiple of the maintenance interval replacement years coincide with maintenance years. If a component is replaced in a particular year maintenance is not required that year, therefore the number of replacements is deducted from T/r in the equation. Example:  40 year building, (T), 8000MJ component, (X) 12 year replacement interval, (r) 3 year maintenance interval, (m), 25% maintenance percentage, (%m) M = (int ( 40/3) - (int(40/12)) * (8000/100 * 25) = (int(13.33) - (int (3.33)) * 2000 = 13-3*2000 = 20000MJ Total life-cycle embodied energy = Initial embodied energy plus embodied energy resulting from replacement plus embodied energy resulting from maintenance = X + R+M  

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