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Energy conservation in office buildings Leu, Max Hans 1980

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ENERGY CONSERVATION IN OFFICE BUILDINGS' by MAX HANS'.LEU DIPL. ARCHITECT SWISS FEDERAL INSTITUTE OF TECHNOLOGY, ZUERICH 1978 r;:.yJfii.THESIS^-SUBMITTED-IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARCHITECTURE i n THE FACULTY OF GRADUATE STUDIES SCHOOL OF ARCHITECTURE . We accept th i s thesis as conforming to the required standard THE.UNIVERSITY OF BRITISH COLUMBIA June 1980 ( c ) ' Max Hans Leu, 1980 In presenting th i s thesis in pa r t i a l fu l f i lment of the requirements for an advanced degree at the Univers ity of B r i t i s h Columbia, I agree that the Library shal l make i t f ree ly avai lable for reference and study. I further agree that permission for extensive copying of th i s thesis for scholar ly purposes may be granted by the Head of my Department or by his representatives. It i s understood that copying or publ icat ion of th i s thesis for f inanc ia l gain shal l not be allowed without my written permission. 0ax H. Leu D ip l . Arch. ETH/SIA The Univers ity of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 Date / f SOUL /f8o i E - 6 B P 7 5 - 5 1 1 E - i i -ABSTRACT This study presents a framework for the introduction of energy cons i -derations into the design of o f f i c e bui ld ings. The method of research and development of th i s study has been through a l i t e r a t u r e search combined with personal design experience in the f i e l d of commercial bui ld ings, and the previous par t i c ipat ion in the national competition for low energy bui lding design. The thesis i s in two parts. The f i r s t part investigates the h i s t o r i c a l development of o f f i ces up to now and shows that current.of-f i c e design practice establishes a pattern of high energy consumption that is carr ied forward for decades. It i s shown how and where energy is used in o f f i c e buildings and the i r urban context. The need to re-think settlement patterns i s outl ined and the concept of decent ra l i -zation and mixed use developments is suggested to improve overal l energy e f f i c iency in the urban context. The second part presents energy conservation s t rateg ies , from a designer 's point of view, that improve energy e f f i c i ency of o f f i c e bui ldings. Five basic strategies are introduced and examined at the planning levels of s i t e , lay-out, form and f ab r i c : i ) to control internal heat gains i i ) to control solar heat gains i i i ) to minimize heat losses iv) to optimize natural vent i l a t i on v) to maximize dayl ight capab i l i t i e s of buildings The thesis shows that the implementation of these strategies pre-sents the arch i tect with considerable scope for innovation rather than imposition. However, i t is emphasized that the arch i tect must be aware of the consequences of his design decis ions. The factors causing the energy use in o f f i c e buildings are i n t e r r e l a -ted. Therefore, once a par t i cu la r strategy i s adopted i t s conse-quences have to be recognized and dealt with on a l l planning leve l s . The thesis concludes that energy conservation offers a r ch i -tects the opportunity to design o f f i ces in a way they need less energy and provide a better working environment than i t i s the case today. - „ i v -TABLE OF CONTENTS Page ABSTRACT i i TABLE OF CONTENTS • . . . iv LIST OF TABLES v i i i LIST OF FIGURES. ix ACKNOWLEDGEMENT. . .. x i i i CHAPTER I: INTRODUCTION . . 1 1. THE ENERGY CRISIS 2. ENERGY CONSERVATION 3. ENERGY AND ARCHITECTURE 4. THESIS STRUCTURE 5. NOTES PART ONE: OFFICE BUILDING DESIGN. 17 CHAPTER II: THE OFFICE IN THE URBAN CONTEXT 18 1. INTRODUCTION 2. HISTORY OF OFFICES 2.1. Pre- Industr ial Revolution 2.2. Off ice Growth 2.3.1. Off ice Automation 2.3.2. Growth of Off ice Employment 2.3.3. Energy Implications 3. TODAYS OFFICE IN THE URBAN CONTEXT 3.1. Location Factor: Prestige 3.2. Location Factor: A c ce s s i b i l i t y 3.3. Location Factor: Communication 4. STRATEGIES IN THE URBAN CONTEXT 4.1. Decentral ization 4.2. Mixed Development 4.3. Implications 5. NOTES CHAPTER III: THE OFFICE BUILDING 44 1. INTRODUCTION - V -Page 2. BUILDING SHELL 2.1. Form 2.2. Materials 3. BUILDING LAY-OUT 3.1. History of Daylighting 3.2. Standard Lay-out Pract ice 3.2.1. Ce l l u l a r Off ices 3.2.2. Open Plan Off ices 3.3. New Lay-out Concepts 4. THE WORKSTATION 5. NOTES PART TWO: ENERGY CONSERVATION STRATEGIES. CHAPTER IV: ENERGY MANAGEMENT STRATEGIES. 76 77 1. 2. 5. 6. INTRODUCTION PERSONAL FACTORS 2.1. Temperature Range 2.2. A c t i v i t y and Clothing 2.3. Vent i la t ion Rate 2.4. Lighting Levels OPERATIONAL CHARACTERISTICS 3.1. Hours of Operation 3.2. Operation with Respect to A c t i v i t i e s MECHANICAL AND ELECTRICAL SYSTEMS DESIGN 4.1. Mechanical System 4.1 4. 4. 4. 4.2. System Capacity System Selection System Maintenance D i s t r ibut ion of Energy around Building Heat Recovery Systems The Lighting System 4.2.1. System Design and Selection 4.2.2. System Maintenance 4.2.3. Heat-of-Light System 4.1.5. CONTROL SYSTEMS DESIGN NOTES CHAPTER V: OFFICE BUILDING DESIGN STRATEGIES. . . . . . . . 1. INTRODUCTION 2. PLANNING LEVEL: SITE 2.1. Objective 2.2. Analyze S i te Climate 2.3. Design in a Climate-Responsive Manner 99 - v i -2.4. Provide Solar Access 2.5. Maximize Daylight Potential 2.6. Optimize Potential for Material Vent i la t ion 3. PLANNING LEVEL: LAY-OUT 3.1. Objective 3.2. Thermal Zoning 3.2.1. Perimeter Zone 3.2.2. Core Zone 3.3. Maximize Daylight Potential 3.3.1. Increase of Perimeter 3.3.2. Internal Par t i t ions 3.4. Control Heat Loss and Solar Heat Gain: Buffer Concept 3.5. Control Internal Heat Gains 3.6. Create Potential for Natural Vent i la t ion 4. PLANNING LEVEL: FORM 4.1. Objective 4T2. Reference Buildings 4.3. Heat Loss 4.3.1. Reduce Transmission Heat Loss 4.3.2. Reduce Vent i la t ion Heat Loss 4.3.3. I n f i l t r a t i o n 4.4. Heat Gain 4.4.1. Reduce Solar Gain 4.4.2. Selective Treatment of Solar Gains 4.4.3. Optimize Natural Vent i la t ion Potential 4.4.4. Reduce Internal Heat Gains 4.5. DayTighting Design: Maximize Daylighting Potential 4.5.1. Sunlight and Daylight 4.5.2. Window and Daylight 4.5.3. A t r i a 5. PLANNING LEVEL: FABRIC 5.1. Objective 5.2. Window Design Strategies i 5.2.1. Exter ior : Consider Orientation 5.2.2. Exter ior Accessories: Control Solar Gain 5.2.3. Window Glass: Minimize Heat Loss, Minimize Solar Gain and Provide Daylight 5.2.4. Inter ior Accessories: Control Natural Light 5.2.5. Inter ior : Cap i ta l i ze Upon Daylight Potential and Upon Select ive Treatment of Solar Gains - vn -Page 5.3. Wall Design Strategies 5.3.1. Insulation: Minimize Heat Loss 5.3.2. Thermal Capacity: Increase . Thermal Mass 5.3.3. Exter ior Colour and Texture: 5.4. Reduce Heat Gains Roof Design Strategies CHAPTER VI: CONCLUSIONS 200 PART THREE: REFERENCE MATTER 206 BIBLIOGRAPHY 207 1. REFERENCE MATERIAL CITED 2. SOURCES CONSULTED APPENDIX A: CLIMATIC ELEMENTS 227 APPENDIX B: COMPETITION FOR LOW ENERGY BUILDING DESIGN 234 - v i i i -LIST OF TABLES 2.1. Major Inventions Affect ing Off ice Development 23 2.2. Speci f ic Energy Consumption According to Mode of Transport 36 4.1. Factors Influencing Energy Use 81 5.1. Window System Design 168 5.2. External Accessories 173 6.1. Summary 205 LIST OF FIGURES Figure Page 1.1. The Major Divis ions of National Energy Use 9 1.2. Energy Use Curve of Buildings 10 29 2.1. Off ice Employment in the United States 2.2. Of f ice and Reta i l Space in Vancouver 3i 2.3. Decentralized Land-Use Model 37 2.4. Mixed Development. 39 2.5. Power Demand P r o f i l e of a Commercial/Residential Bui lding. 40 3.1. Breakdown of Off ice Energy Use 45 3.2. Energy. Use for an Off ice Building in Warm and Cold Climates 46 3.3. Relative Ef fect of Energy Conservation . . . . 47 3.4. Estimated National Inventory of Off ice Floor Space . . . . 4 8 3.5. Structured Systems and Building Height . . . 50 3.6. Steel Demand for Ta l l Buildings 50 3.7. Floor Plans of the IBM Building in Chicago 52 3.8. Development of Window. . 53 3.9. Shallow Dayl i t Off ice Space 57 3.10. Medium Deep Off ice Space :- 58 3.11. Deep Off ice Space 59 3.12. Ce l l u la r Off ices 62 3.13. Open Plan Off ices 65 3.14. Central Beheer Insurance Company Bui ld ing, Appeldorn, Holland. Arch i tect Hertzberger. . 69 - x -Figure Page 3.15. Atrium-Type Off ice Building 70 3.16. O l i v e t t i Workstation 72 79 4.1. Breakdown of Off ice Energy Use Q O 4.2. Comfort Diagram 5.1. Solar Envelope 109 5.2. Solar Envelope and Adjacent Buildings 110 5.3. Example. I l l 5.4. Courtyards for Daylight . 112 5.5. Ref lect ive Surface Increases Daylight Potent ia l . . . . . . 113 5.6. External- Internal Environment 116 5.7. Core and Perimeter Zone 117 5.8. Perimeter Zone 118 5.9. Core Zone 119 5.10. Increase of Perimeter 120 5.11. Daylight Potential and Internal Par t i t ions . . . . . . . . 122 5.12. Parking Space as a Buffer Zone . 123 5.13. Typical Internal Heat Gains 124 5.14. Natural Vent i la t ion in Atrium 126 5.15. Building Types Examined 130 5.16. Heat Loss and Building Form 134 5.17. Building Form and I n f i l t r a t i o n 139 5.18. Building Height and I n f i l t r a t i o n 139 5.19.. Internal Heat Gains Af fect ing Heating Demand 140 5.20. Summer Heat Gains. 143 - x i -Figure Page 5.21. Theoretical Clear Sky Radiation Data for Vancouver Area. . '144 5.22. Solar Gain and Orientation . 145 5.23. Buffer Zone 147 5.24. Energy E f f i c iency Through Double Skin 148 5.25. Energy Use for Lighting 150 5.26., Interrelat ionship Heating/Cooling/Lighting . . . . . . . . 150 5.27. Reduction of Lighting Heat Gains . 152 5.28. Beam Daylighting 155 5.29. Beam Daylighting Apparatus 157 5.30. Daylighting 158 5.31. Atrium vs. Highrise 159 5.32. Courtyards for Light 160 5.33. Atrium Example 161 5.34. Fabric as a Cl imatic Modif ier 164 5.35. The Window System. 167 5.36. Sun Angles on South Facing Window. . 171 5.37. Solar Control. and.Daylight Penetration 174 5.38. Energy Consumption and Window Area 176 5.39. Posit ioning of the Window in the Wall. . . . . . . . . . . 177 5.40. Ef fect .of Solar Control Glasses 179 5.41. Inter ior Lighting 181 5.42. Buffer Zone and Solar Gains. 182 5.43. Optimizing Insulation Thickness 183 5.44. Pre-Cooling of. an Off ice Structure 185 - x i i -Figure Page 5.45. Venti lation.and Insulated Facade Construction .187 5.46. Measured Solar Radiation Data for Vancouver, Horizontal And Vert ica l Surfaces. 188 - x i i i -ACKNOWLEDGEMENT I wish to thank a l l those who have helped me through conversations and suggestions to carry out my research project: • Dr. Brongers of the Main Library for his help in conducting the computer l i t e r a t u r e search. • Mr. Terry Catel l of Musson & Catel1, Arch i tect s , for his i n fo r -mation as a pract ic ing arch i tect in the f i e l d of commercial b u i l -dings. • . Gerard Wagner, Arch i tect MRAIC, for the opportunity to co l labo-rate in the Competition for Low Energy Building Design, and for for his esteemed advice throughout my studies. • Dino Rapanos for his encouraging help in the course of the study and for his suggestions to explore the wider implications of the energy problem,, notably the philosophical and social dimensions. • Ray Cole for the numerous discussions which helped me to c l a r i f y the issues and form a cohesive thes is . Espec ia l ly , I would l i k e to thank Ray Cole for the opportunity to write with him an a r t i c l e on "Energy and Form Considerations in Commercial Bui ldings" in the AIBC - Forum, June 1980. This a r t i c l e i s integrated extensively in the f i f t h chapter of the thes i s . • F i n a l l y , I wish to express my thanks to Mr. C..R. Brupbacher for his assistance and to the University of B r i t i s h Columbia for the Graduate Fellowship which allowed me to stay in Canada. CHAPTER I: INTRODUCTION 1. THE ENERGY CRISIS 2. ENERGY CONSERVATION 3. ENERGY AND ARCHITECTURE 4. THESIS STRUCTURE 5. NOTES - 2 -CHAPTER I: INTRODUCTION 1. THE ENERGY CRISIS Human existence depends on energy and the development of c i v i l i z a t i o n para l le l s an increase in energy use. Unt i l the Industrial Revolution, man depended almost exclus ively on the natural elements - sun, water, wind and f i r e - as sources of energy. In the pre- industr ia l era the production of energy was c lose ly ' re lated to ag r i cu l tu re , the primary sector of the economy. The Industrial Revolution, which began with Watt's invention of the steam engine in 1782, caused the transformation of a society whose energy base was agr icu l ture to one whose energy base i s f o s s i l f u e l s J After man learned e f fec t i ve techniques of energy conversion, such as the steam engine, he recognized the demand of fue l s exceeded the immediately renewable energy resources and that the known sources of fuels were l im i ted . The knowledge of how fuels could be obtained and what substances could be used as fuels became important. After 1782 the production of mechanical energy from f o s s i l fuels became increasingly important and soon dominated a l l other forms. The use of renewable energy, such as wind power and sun radiat ion was systematical ly replaced by the energy derived from f o s s i l fue l s . Simultaneously, the demand for energy rose exponentially. I n i t i a l l y , new resources of fuel were discovered or created at a faster rate than they were expended. For the fol lowing 200 - 3 -years, energy from f o s s i l fuels was abundant and cheap. Within the l a s t decade, however, the use has come to exceed the rate of discovery. The Middle East War in 1973 brought a temporary shortage of f o s s i l f ue l s , which were believed to be abundant and inexhaustible. This event became known as the "energy c r i s i s . " At once, people in the indus t r i a l i zed soc iet ies became aware of the l imited supply of cheap energy, and the fact that current rates of use would inev i tably deplete the supply of f o s s i l fuels on which a l l i n - • • i n -dus t r i a l i zed soc iet ies are based. Energy became an issue. Since, then i t has been the subject of substantial coverage by the media and the technical press. Alarming studies, such, as "The L imits . to Growth" 3 pointed out that our natural resources are being depleted rap id ly . Since the earth is of f i n i t e s i ze , i t i s log ica l that i t ' s resources are f i n i t e . To emphasize these 1 imitat ions, the concept of the "Spaceship Earth" was introduced.^ If resources are f i n i t e , one must consider the problem of depletion and the need for conservation. I t i s only prudent to assess the resources ava i l ab le , the rate at which they are being expanded, and the time required to deplete them. Attempts to assess resources are d i f f i c u l t to make, since there is s t i l l contrar iety on the question when a raw material actua l l y becomes a resource. Raw materials which represent potential energy, are abundant on the planet, but only those that man has located and knows how to make use of, can actua l ly be considered as resources.^ - 4 -The current o i l s i tuat ion is i l l u s t r a t i v e here. Extremely slow geological forces created th i s chemical form of energy. For thousands of years, i t was inaccessible and therefore useless to man. Only very recently, technological progress made i t access ible. Since then, the reserves have been systematical ly explo i ted. The o i l reserve problem can be compared to a necklace of pearls that has broken on the f l o o r . The most v i s i b l e pearls would be picked up f i r s t and those not so obvious are discovered l a t e r . By comparison, the most eas i l y accessible o i l reserves were fast expended. Now, o i l i s extremely d i f f i c u l t to f i n d , must be transported long distances and. is therefore expensive. In the years fol lowing the energy c r i s i s , i t became c lear that the energy problem i s a manifold one. It involves environmental, social and p o l i t i c a l aspects. 7 It was recognized that the energy c r i s i s was not pr imar i ly caused by i n su f f i c i en t supply, but rather by the ever-increasing demand of the af f luent nations of the world.. It i s imperative to analyze and question the fundamental philosophies of these consumer soc ie t ie s . They have been extremely successful in producing material goods. But th i s success was a material success only and one at the expense of nature. Major s o c i a l , p o l i t i c a l and ecological problems have resulted from the wasteful systems of production and consumption. Resource supply bottlenecks, po l lut ion and p o l i t i c a l d isruption o show the f a i l u re s of th i s approach. As an a l te rnat i ve , the concept of the "conserver society" has Q been introduced. Instead of wasting non-renewable resources, the - 5 -conserver society draws on renewable resources and employs pr inc ip les that el iminate the wasteful use.of energy. However, the implications of a conserver society go far beyond the level of energy use. The central concern is to provide a higher qua l i ty of 1 i fe . The change of our consumer society to a conserver society w i l l not be rea l ized overnight. It w i l l involve changes in att i tudes and l i f e s t y l e s . Both are processes that may take generations to achieve. Nevertheless, i t i s necessary to proceed toward that ultimate goal. With respect to energy, the solut ion depends on a re-d i rect ion of our po l i c i e s . The focus must be on the demand problem rather than on the supply problem, on conserving energy by using i t more thoughtful ly. Schumacher points out a conserver society can even do more with l e s s . ^ - 6 -2. ENERGY CONSERVATION The F i r s t Law of Thermodynamics.states that energy cannot be created nor destroyed.^ It might appear that th i s law offers the solut ion for our energy problems, since energy is "conserved" according to th i s de f i n i t i o n . However, the Second Law of Thermo-dynamics gives the reasons why we are. s t i l l stuck in ah energy shortage. The Second Law,"in s imp l i f i ed form, states that no physical process i s completely revers ib le. Once a process has taken place, the or ig ina l condition cannot be restored without 12 something else being affected. There are d i f fe rent grades of energy: mechanical arid e l e c t r i c a l energy are of the highest form. Heat and chemical energy are of a lower form. A very important consequence of the Second Law is that low grade energy can never be changed t o t a l l y into higher grade energy. There are always f r i c t i o n a l processes which d iss ipate part of the energy in form of low grade heat. Therefore, the energy we use for physical processes l i k e dr iv ing a motor or heating buildings i s not destroyed but is converted from high grade energy into low grade energy. What society needs to conserve is not the energy alone, but the high grade energy, which is more useful to us. This raises the problem of e f f i c i ency . Since the Second Law states only that there must be a portion that is not f u l l y converted, but not how much, i t i s possible to improve the conversion processes in order to come to 100% e f f i c i ency . In l i g h t of th i s p r inc ip le - 7 -there is a potential for s i gn i f i can t energy savings. For instance, the e f f i c iency is greatly improved i f the r ight kind of source energy is matched to a par t i cu la r task. To heat a bui ld ing with high grade e l e c t r i c a l energy generated in a gas-f i red power plant is inherently less e f f i c i e n t than to burn the gas d i r e c t l y in the heating equipment of the bui ld ing. A l l th.is suggests that the solut ion to the energy problem should not focus on conservation alone. Nevertheless, I shal l use the term "energy conservation," because i t i s commonly accepted and in widespread use throughout the l i t e r a t u r e . Under "energy conservation," I understand ways to reduce the wasteful use of high grade energy and. strategies to use i t more e f f i c i e n t l y . - 8 -3. ENERGY AND ARCHITECTURE Architecture is the resu l t of numerous influences. Generally, i s expresses the basic values of society: i t s needs, att i tudes and desires. If the indus t r i a l i zed society is characterized by the wasteful use and the explo i tat ion of the natural resources, architecture w i l l r e f l e c t th i s a t t i tude. A s i gn i f i cant portion of contemporary architecture shows a consistent under-estimation of the natural environment and r e l i e s almost en t i re l y on a r t i f i c i a l support systems. This i s the main reason for the s teadi ly growing energy demand. It i s widely recognized that the amount of energy that is needed to operate buildings exceeds one-third of the to ta l energy demand of indust r ia l s o c i e t i e s . ^ As outl ined e a r l i e r , the long-term solut ion to our energy shortage and related problems l i e s in development of the conserver society. Since the re la t i on between architecture and society is dynamic, the change toward a conserver society w i l l have fundamental implications on architecture. The change must s ta r t from today's s i tua t ion . The bu i l t environment must gradually improve in terms of energy e f f i c iency and must r e f l e c t the growing energy consciousness. The underlying philosophy of the conserver society can be used as a cont ro l l i ng framework to achieve an energy-conserving bu i l t environment. Figure 1.1.: The Major Divis ions of National Energy Use Shaded areas indicate energy use affected by arch i tectura l decis ions. The breakdown of the national energy use in Figure 1 i den t i f i e s the large portion of energy consumption affected by arch i tectura l decisions. 25% of a l l energy consumed in the United States in 1970 was related to e l e c t r i c a l generation. Of th i s 25%, one hal f was used for l i g h t i n g , vent i l a t ing and a i r - cond i t i on ing , as well as operating elevators, pumps, fans and the l i k e . Space heating and coo l ing, and the preparation of domestic hot water represented an addit ional 20% of the tota l energy consumption. A f r ac t i on of the energy used for transportation and industry i s also affected by arch i tectura l decis ions. A l l together, about 43% of the to ta l energy consumption is d i r e c t l y related to arch i tectura l decis ions. It is obvious, then, that in order to reduce energy consumption, i t i s necessary to re-examine the use of energy in bui ld ings. - 10 -The energy used throughout the l i f e of a bui ld ing may be represented graphica l ly , as shown in Figure 2. The energy use curve is a s imp l i f i c a t i on of the actual energy consumption of a bui ld ing over i t s l i f e t ime . Figure 1.2.: Energy Use Curve of Buildings 16 CONSTRUCTION z OPERATION DEMOLITION II III IHI I IH11 I I11 1 | i l l | | | | I I I I I I I H H H I | l | | y 0 1 2 47 48 A3 YEARS In the f i r s t stage, energy is used to manufacture bui ld ing materials and to assemble these materials during construction. In the second stage, energy i s consumed for maintenance and operation throughout the l i f e of the bu i ld ing. This is characterized by an undulating curve which represents the seasonal var iat ions. This component gradually increases as the bui lding becomes older and i t s equipment less e f f i c i e n t . The eventual demolition of the bui lding in the th i rd stage results in a temporary increase in energy expenditure with a subsequent drop to zero. Whereas the f i r s t and the l a s t stage are non-recurrent inputs, the operation process consumes energy over the f u l l l i f e c y c l e of the bui ld ing. This indicates that design decisions have an e f fect on the energy consumption of a bui lding over i t s l i f e t i m e . Architectural decisions of the bui lding form and fabr ic therefore establ ish a pattern of energy consumption that i s carr ied forward for decadesJ 7 This observation.suggests that the improvements of ex i s t ing structures i s important and that design decisions have to be based on the evaluation of the i r effects over the whole l i f e t ime of bui ld ings. Commercial buildings represent a considerable portion of our b u i l t environment. Commercial buildings are equipped with more sophisticated mechanical and e l e c t r i c a l sytems than res ident ia l bui ldings. Consequently, a disproportionate amount of energy i s consumed in such bui ldings. For instance, the major part of the energy related to e l e c t r i c a l generation is used for l i g h t i n g , vent i l a t ion and a i r -condi t ion ing commercial bui ld ings, whereas the energy consumption for these requirements are quite i n s i gn i f i can t in res ident ia l bui ldings. Commercial buildings are therefore considered as a main target for energy conservation. This study focuses on the o f f i c e bui ld ing. However, i t i s apparent that many other non-residential buildings use energy in a s imi la r way and that therefore the same pr inc ip les apply. - 12 -The o f f i c e bui lding was chosen because th i s bui lding type has become one of the most extreme representatives of an arch i tectura l approach that uses energy in a wasteful way. Modern o f f i c e buildings consume more than twice as much energy per unit f l oo r area than 25 years ago. The sealed glass-box o f f i c e tower i s a bui ld ing type found in c i t i e s a l l over the world, despite wide c l imat i c d i f fe rences . 1 I consider i t to be a more challenging task to look at o f f i c e buildings rather than res ident ia l bui ld ings, because r e l a t i v e l y l i t t l e research has been undertaken in th i s f i e l d with respect to energy and design problems. However, the i n i t i a l spur came from my successful, par t i c ipat ion l a s t year in the competition for low 19 energy bui ld ing design, sponsored by the Government of Canada. It i s an important task for architects to re-evaluate the development of the design of o f f i c e bui ld ings. Studies suggest that up to 50% of the energy used to operate o f f i c e buildings can 20 21 22 be saved by improved design. ' ' There i s a great need to design o f f i ce buildings in a way that they use less energy and provide a good working environment. - 13 -4. THESIS STRUCTURE This thesis provides information from a designer 's point Of view for a f i r s t step toward a conserver society. As the change cannot be achieved immediately, strategies are proposed that 23 allow a gradual change toward th i s ultimate goal. Af ter the introduction chapter, the f i r s t part, Chapters II and I I I, gives an overview of the present s i tuat ion and analyzes how and where energy is used in o f f i c e buildings and the i r urban context. Chapter II shows the h i s t o r i c a l development of the o f f i c e and i t s energy-use implications in order to understand the present s i tuat ion . The o f f i ce is analyzed in i t s urban context and the strategy of decentra l izat ion and multi-use is suggested to achieve substantial energy savings on an urban scale. Chapter III deals with the scale of the indiv idual o f f i ce bui ld ing. The energy consumption pattern in o f f i c e buildings is analyzed to ident i f y the main factors which influence the i r energy use. An overview of the development and the current design practice of the indiv idual bui lding is given, followed by the respective implications in energy terms. The survey proceeds from the level of the bui lding shel l over the lay-out patterns to the level of the indiv idual workstations. The second part, Chapters IV and V, presents energy conservation strategies. Chapter IV outl ines energy management strategies in o f f i ce bui ldings. Chapter V deals s p e c i f i c a l l y with bui ld ing design strategies which aim at achieving energy e f f i c i ency . The - 14 -general objective i s to achieve a balance between the c l imat ic conditions of the exter io r , and the internal environmental factors which influence the use of energy. For th i s purpose, the bui ld ing design strategies are treated at four planning l eve l s : i ) Planning level s i t e . The re lat ionsh ip of the bui ld ing to the ex i s t ing c l imat ic conditions and the influence of adjacent buildings i s considered, i i ) Planning level lay-out. Conservation strategies for the spacial organization with respect to energy use are out l ined, i i i ) Planning level form. Strategies are presented which indicate how the shape, s ize and or ientat ion of a bui lding can be used to achieve improved energy e f f i c i ency , iv) Planning level f ab r i c . Strategies for window and wall design and the se lect ion of bui lding materials are presented. Strategies for energy e f f i c iency should be applied on a l l of these leve l s . Design decisions at a higher level help to lessen the impact of the environmental factors which must be dealt with at a lower planning l e v e l . In p ract i ce , however, a var iety of constraints can l i m i t the implementation of energy conscious design strategies at d i f fe rent l eve l s . The th i rd part, Chapter VI, summarizes the f indings and puts i t into perspective of the future development in o f f i c e bui ld ing design. - 15 -5. NOTES 1. Ray J . Cole, "Energy Conscious Design F i l e , " AIBC-Forum, November 1978, p. -16. 2. Andrew G. Hammitt, "Knowledge and'the Energy C r i s i s , " Tack Ting., the C r i s i s . Proceedings of the Los.Angeles Council of Engineers Energy Symposium 1976 (Los Angeles, Ca.: Los Angeles, Council,,of Engineers, 1976), p. 76. 3. Donella H. Meadows et a l t e r i , The Limits to Growth ,(New York: Universe Books, 1972). 4. Richard B. Fu l l e r , Operating Manual for Spaceship Earth (Carbondale: Southern Univers ity Press, 1969). 5. Ernest W. Zimmerman, World Resources and Industries (New York: Harper and Row, 1951). 6. Barry Commoner, The Poverty of Power (New York: Bantam, 1976) p. 43. 7. Ib id . , p. 2. 8. L. Solomon, The "Conserver Solution .-(Toronto: Doubleday Canada, 1978). 9. GAMMA, Conserver Society Project: Report Phase IT, vo l . 1, (Montreal: GAMMA-Group, 1976). 10. Ernest F. Schumacher, S m a l l i s Beauti ful (New York: Harper and Row, 1973), p. 56. 11. Barry Commoner, op. c i t . , p. 4. 12. Andrew G. Hammitt, op. c i t . , p. 80. 13. James M. Fitch, "Pr imit ive Architecture and Cl imate," S c i e n t i f i c American 203 .(December 1960) 14. Jan Kalas, "Energy in Commercial Bu i ld ings, " paper presented at the Energy Conservation Conference, Capilano College, Vancouver, 1975. 15. Richard G. Ste in, Architecture and Energy (New York: Anchor/Double-day, 1978), p. 13. 16. Ib id. , p. 10. 17. Ray J . Cole, op. c i t . (November 1978), p. 16. - 16 -18. John Hix, "Energy Conservation and the Arch i tect : Part I," The Canadian Arch i tect , February 1977, p. 20. 19. Competition for How Energy Building Design Awards (LEBDA), Government of Canada, represented by the Minister of Energy, Mines and Resources and the Minister of Public Works. Design Team: Gerard Wagner, Viviane Hotz, Howard Rice-Jones and Max Leu. See also Appendix B. 20. Richard G. Salter et a l t e r i , Energy Conservation in Non-Residential Buildings (Santa Monica, Ca.: The Rand Company, 1976) p. v i , indicates savings of 40% to 50%. 21. Richard G. Ste in, op. c i t . , p. 14, indicates savings of 43%. 22. .', - *, "Round Table on Cost-Effect ive Strategies for Saving Energy in Bui ld ings, " Architectural Record, Mid-August 1977, p. 92, indicates savings of 34%. 23. The concept of the conserver society was studied pr ior to th i s thesis in a directed study under the supervision of Dino Rapanos, UBC, School of Architecture, Spring 1979. - 1 7 -PART ONE: OFFICE BUILDING DESIGN - 18 -CHAPTER II: THE OFFICE IN THE URBAN CONTEXT 1. INTRODUCTION 2. HISTORY OF OFFICES 2.1. Pre- Industr ial Revolution 2.2. Industrial Revolution 2.3. Off ice Growth 2.3.1. Off ice Automation 2.3.2. Growth of Off ice Employment 2.3.2. Energy Implications 3. TODAY'S OFFICE IN THE URBAN CONTEXT 3.1. Location Factor: Prestige 3.2. Location Factor: A c ce s s i b i l i t y 3.3. Location Factor: Communication 4. STRATEGIES IN THE URBAN CONTEXT 4.1. Decentral ization 4.2. Mixed Development 4.3. Implications 5. NOTES - 19 -CHAPTER II: THE OFFICE IN THE URBAN CONTEXT 1. INTRODUCTION This chapter examines the h i s t o r i c development of the o f f i c e in an urban context and, more s p e c i f i c a l l y , those factors which have an' influence on energy consumption. Currently, o f f i ces dominate c i t y centres in both a physical and economic sense. The o f f i ce can be considered as the peak of a pyramid of work and money and decis ions. The basic function of an o f f i c e is one of d i rect ing and coordinating the a c t i v i t i e s of an enterprise. Off ice employment is provided in construct ion, transport and communications, d i s t r i bu t i on trades, banking and f inancing, professional services and public administrat ion. However, today's o f f i ces cause substantial problems in the c i t y centres. The most s i gn i f i cant of these is the segregation of the basic a c t i v i t i e s of l i f e , such as work and le i sure and i t s attendant transportation problems. As the end of the chapter the strategies of decentral izat ion and mixed development are proposed to improve energy e f f i c i ency in the urban environment. - 20 -2. HISTORY OF OFFICES 2.1. Pre- Industr ial Revolution Pr ior to the Industrial Revolution, the main functions of c i t i e s were defence, trade and p o l i t i c a l administration. Most of the transactions between individuals.were made in the marketplace in a d i rect and simple manner. The basic information needed for dec is ion-making was obtained verbal ly and without sophist icated communication equipment. In th i s context, o f f i c e a c t i v i t i e s played a minor role in the economy. The production process was dominated by small organizations, which did not require extra space and s k i l l for spec ia l ized o f f i c e a c t i v i t i e s . The o f f i ce was phys ical ly l inked to the manufacturing place. The typ ica l o f f i c e workers, were the accountant and the c lerk . Gradually, the need emerged to set aside rooms for counting money and since the o f f i c i a l s of the factory used them, they also became known as " o f f i c e r s ' " rooms. The terms "accounting" and " o f f i c e " could well have been derived from these expressions.^ In terms of energy consumption, the o f f i ces were i n s i gn i f i c an t . The whole society was based on natural energy sources and the mechanical energy was gained predominantly through muscle power of man himself and of domestic animals. The small scale operations in a l imited market s i tuat ion had a small demand for transportation and i t s attendant energy consumption. L i t t l e energy was used to maintain comfort conditions in bui ld ings, since there were only wood and coal stoves to heat the space in winter. People adapted to t he i r environ-ment with indiv idual s t rateg ies , such as changing clothing habits. - 21 -2.2. Industrial Revolution The invention of the steam-powered engine by Watt in 1782 was the begining of a profound change in society. I t gave b i r th to mass-production and the growth of c i t i e s . The manufacturing industry became concentrated close to the centre of c i t i e s , thus acting as a magnet for rural people looking for employment. The concentrated organization of production and the greater product iv ity of machines created larger companies. Such concentration of labour and production inev i tably led to an increasing demand for the management of growing and complex organizations. Another consequence of the expanded indust r ia l a c t i v i t i e s in the c i t i e s was the requirement for considerable f inance, insurance and other services. A l l these factors created office-based workers providing a wide range of s pec i a l i s t services. Eventually, o f f i ces became phys ica l ly separated from the production plants and established the i r own ident i t y . This had three major implications on the physical and economical development of the c i t i e s : i ) the need for communication and transportat ion; i i ) the trend toward cen t r a l i z a t i on ; i i i ) the appearance of the o f f i c e workers. - 22 -i ) The need for communication and transportation arose. Improve-ments in the technology of communications and data processing permitted an e f f i c i e n t re la t ion between the o f f i c e and the production plant, even i f they were separated. The development of o f f i c e equipment was also used to minimize .1abour to perform routine tasks as well as to increase the speed at which these tasks were performed. The typewriter f a c i l i t a t e d greater speed in the recording and reproduction of information; the telegraph permitted exchange of information over greater distances at lower cost. Communications had emerged as one of the key factors in the o f f i c e and i t s ro le was completed by the telephone. The impact of the telephone was immense. It promoted the expansion of the t y p i s t ' s function because i t permitted oral contact without meeting face to face. Some of the most important inventions a f fect ing the development of the o f f i ce industry are presented in Table 2.1. - 23 -Table 2.1.: Major Inventions Affect ing Off ice Development i Energy supply and application j 1 1834 Electric motor ( M . H . von Tacobi) , I 1854 Hydraulic passenger elevator (E. G. Otis) i 1879 Electric lamp (T. A . Edison) t ! 1881 First commercial electric power plant (Pearl Street, New York) j 1887 First successful electric street railway (F. J. Sprague, Richmond) i j 1887 First electric elevator 1 | Information transmission ' ' 1833 Electromagnetic telegraph (F. Gauss and W . Weber) ] 1866 First successful transatlantic telegraph cable j 1876 Telephone (A. G. Bell) • 1878 First commercial telephone switchboard (New Haven) j Information handling j 1837 Stenography (Pitman) 1 1874 Commercial adaptation of the typewriter (Remington) i 1888 Stenography (Gregg) '] I 1894 Commercial adaptation of the mechanical calculator ^ 1 (W. S. Burroughs) > • Building construction ] 1884 Steel frame (Home Insurance Co. Building in Chicago, ten | floors, by William Le Baron Jenney) 1 1889 First steel frame high-rise building in New York (Tower Building , at 50 Broadway, eleven floors, by Bradford L. Gilbert) i i ) The second impl icat ion of the growing independence of o f f i ce s from manufacturing plants was the trend toward cen t ra l i z a t i on . Off ice a c t i v i t i e s started to c lu s te r in c i t y centres. The sale of products, the organization of business a c t i v i t i e s and the d i rec t communication with f i nanc ia l i n s t i t u t i on s required a central locat ion for the o f f i c e . At about the same time that industry ' s managers and o f f i c e s t a f f were moving to down-town locat ions, production-l ine operations were beginning to move further outward from the c i t y centre. - 24 -The th i rd impl icat ion of the separation of the o f f i c e from the production plant was the appearance of the o f f i c e worker as a separate socio-economic group.^ They were employees who undertook the supervis ing, a na l y t i c a l , administrative and mercantile functions delegated to them by the i r employers. O r i g i na l l y , o f f i ce workers had a r e l a t i v e l y high average income, a large degree of job secur i ty and superior chances of r i s i n g to supervisory posit ions (upward mob i l i t y ) . They.also enjoyed advantages such as cleanl iness and comfort in the workplace, and statutory holidays. These factors contributed to t he i r social status. In turn, th i s status required a certa in behavioural pattern that was expressed, for instance, in the i r mode of a t t i r e . The "white c o l l a r , " t i e and su i t for men was a formal ity that is s t i l l required today. Consequently, the o f f i c e workers can make only l imited adjustments in the i r c lothing to achieve greater comfort while working. Since these adjustments in c lothing are often inadequate, a more control led environment is therefore required to provide comfortable conditions. - 25 -2.3. Off ice Growth The th i rd phase of h i s t o r i c a l o f f i c e development was characterized by the rapid growth of o f f i ces and o f f i c e employment which completed the t rans i t i on from a manufacturing to a serv ice-c dominated economy. The emergence of large business corporations and the cumulative effects of the advancing Industrial Revolution spurred o f f i c e a c t i v i t i e s dramatical ly. Changes in production technology, the scope of markets, communications, business s ize and organizational complexity created the modern o f f i c e industry. 2.3.1. Of f ice Automation The growth of the o f f i c e industry was made possible by a further series of spec i f i c inventions. The steel-framed, t a l l o f f i c e bui lding with i t s ve r t i ca l mass transportation system, the elevator, encourage o f f i c e concentration. The e l e c t r i f i e d t r o l l e y car and the private cars brought o f f i c e workers from both the c i t y and growing suburbs to central o f f i c e c lusters . The commercial adaptation of the mechanical ca lcu lator at the turn of the century started a large scale mechanization with the o f f i c e . However, t h i s was soon succeeded by o f f i c e automation, based on the t rans i s to r developed in 1948. This opened the door to the e lect ron ic industry, which in a short time replaced the t rad i t i ona l mechanical ca lcu lat ing and accounting machines and invaded the o f f i c e with high-speed e lectron ic data-processing equipment. The programmed e lectron ic - 26 -computer encouraged further systematization and automatization of o f f i c e work. A great deal of r epet i t i ve o f f i ce work could then be done in a f ract ion of the time required by normal manual procedures. Computer systems proved to be a very e f f i c i e n t and space-saving method of sort ing data. A l l th i s could be done with a high level of accuracy and a reduction in c l e r i c a l manpower. The introduction of the second generation of o f f i c e equipment had a s i gn i f i cant ef fect on o f f i c e work and demanded extensive internal restructur ing of o f f i ce, organization in order to make use of the improved e f f i c i ency . It became necessary to organize o f f i c e workers in departments, each with the i r own c l ea r l y defined functions. This process was supported by the growing d i f f e ren t i a t i on of labour: o f f i c e work became characterized by a high degree of occupational spec ia l i za t i on . One person no longer concerned himself with a l l phases of o f f i c e operation. Each step became d i s t i n c t and appropriate jobs were created in response. 2.3.2. .Growth of Off ice Employment The technological innovations, and the resu l t ing economic change toward the post - industr ia l service society, led to the growth of o f f i c e employment in three stages: i ) I n i t i a l l y manual labour predominated as indust r ia l production expanded. i i ) In the second stage, manual labour was reduced by fa s t growing, organizational and marketing a c t i v i t i e s . - 27 -i i i ) The th i rd phase involved the predominance of non-manual over Q manual occupations as the service industry grew. Much of the growth in the non-manual occupations can be attr ibuted d i r e c t l y to the increase in off ice-based a c t i v i t i e s , among which c l e r i c a l workers represent the most s i gn i f i can t group. In the l a s t decade job control and the widespread use of the computer have reduced the demand for the t r ad i t i ona l s k i l l s of the c l e r i c a l workers. However, th i s was more than compensated for by the increase of higher order occupations, such as programmers and the l i k e . Commerce, banking, insurance, f inancing and communications are now among the leading sectors of the economy which are responsible for the fas t growth of o f f i c e employment. 2.3.3. Energy Implications The energy implications of the th i rd phase of o f f i c e h i s tory , the rapid o f f i c e growth, are c lose ly related to the technological progress. As the elevator and mass transportation allowed o f f i ce s to concentrate in the c i t y centres, the energy requirements for transportation of people and goods increased. Now the energy use for transportation accounts for about onerquarter of the tota l energy Q consumption in advanced indus t r i a l i zed soc iet ies . - 28 -3. TODAY'S OFFICE IN THE URBAN CONTEXT The geographical locat ion of o f f i c e buildings i s selected by sat i s fy ing a number of constraints. They are related e i ther to the internal corporate processes or to the external context within which the corporation opera te s .^ The former predominate, for example, in the pure indust r ia l o f f i c e , when the location of the o f f i c e is required to be close to the manufacturing process .^ In th i s case the locat ion is predetermined by the structure of the o f f i ce a c t i v i t i e s which are related c lose ly to the production. The optimum locations for a manufacturing plant is that which minimizes labour or transport costs and maximizes p ro f i t s within the framework of producers and consumers.1 Transportation cost for raw material and for re -d i s t r i bu t i on of the f in i shed products i s the major factor in se lect ing the locat ion of manufacturing plants. The distance factor , however, is much less important for o f f i ces because of modern communication techniques. The external constraints of o f f i c e locat ion become important whenever there is a competition between corporations for a share of a certa in business volume. An example is the locat ion of head o f f i ces of large corporations. Economic a c t i v i t i e s generate a demand for o f f i c e premises, s k i l l e d labour and extensive communications. A corporation t r i e s to optimize the se lect ion of a s i t e according to these:three components. There i s de f i n i t e l y a tendency for o f f i ces to c luster geographically in a few places. On a national scale, th i s i s ref lected in the fact that a few large c i t i e s share a high concentration of o f f i c e employees. - 29 -Figure 2.1.: Off ice Employment in the United States In the metropolitan s i tuat ion there is a s imi la r tendency toward concentration of o f f i ces in the Central Business D i s t r i c t (CBD). In a study "Reasons for Being in Downtown Vancouver," companies most frequently mentioned the contact with the external organizations, the cen t r a l i t y of l ocat ion , the general convenience 14 and the prestige of. being downtown. The same study shows that for more than one-third of the sample, the downtown locat ion is considered e s sent i a l , in the sense they could not survive outside of the CBD. Among these corporations are espec ia l ly those of banking, f inancing and insurance. - 30 -Since the o f f i c e locat ion has a major e f fect on the national energy use, i t i s useful to ident i f y the determinants of o f f i c e l o c a t i o n : ^ i ) prestige / t r ad i t i on i i ) a c c e s s i b i l i t y (rents and related costs) i i i ) communications ( ins ide CBD and external) 3.1. Location Factor: Prestige A central locat ion renders economic advantages to large companies, which therefore agglomerate in the business d i s t r i c t . Zoning and c i t y by-laws permit the construction of t a l l buildings that, with t he i r dominating and aggressive connotation, generate prestige for the i r corporate owners'. Smaller service and supply f i rms, such as lawyers, accountants and consultants fo l low. Certain small companies consider a central c i t y address prestigious because of i t s e f fect on the image of the company and i t s products. Some companies also derive prestige from the fact that they are renting o f f i c e space in the same bui ld ing as a renowned giant corporation. i Banks and insurance companies t yp i f y the emphasis placed on prestige. This is not surpr i s ing, since they represent the strongest economic group. Presige i s expressed at a l l leve l s of arch i tectura l decis ions, such as bui ld ing form and i n t e r i o r design. The image and advert is ing value provided by architecture has a tremendous importance in the business world. It can be used to express the power and the values - 31 -of the corporations. In a s imi la r way as churches represented the power centre of the medieval society, the o f f i c e towers express the powerful, pos it ion of the large corporations in today's society. The trend toward prestigious locations and t a l l buildings creates very high densit ies in the centre of c i t i e s that become necessari ly energy i n e f f i c i e n t . Extensive service and transportation f a c i l i t i e s , that use substantial amounts of energy, are required to operate the c i t y centres. Diseconomies and i ne f f i c i enc i e s of large scale are already being experienced in e l e c t r i c a l power generation •j c and c i v i c waste disposal. 3.2. Location Factor: A c ce s s i b i l i t y The degree of a c c e s s i b i l i t y is measured by the ease of 17 d i f f i c u l t y of contact between o f f i ce s . A c t i v i t i e s organize them-selves in urban space according to the degree to which they can afford to turn a c c e s s i b i l i t y into p ro f i t s . S ite rent is a major part of the p r o f i t . The better the a c c e s s i b i l i t y for a s i t e (supplied by superior transportat ion), the higher the rental value. Therefore, rents generally decrease with distance from the major o f f i ce areas. This economic rent theory is the basis for the competition for l imited space in urban areas. A consequence is the pressure to maximize the bu i l t volume on a given s i t e . This leads to an increasing separation of a c t i v i t i e s in c i t i e s , as i l l u s t r a t e d in Figure 2.2. - 32 -F i g u r e 2.2.: O f f i c e and R e t a i l Space i n Vancouver /////// orrices Retailers A c t i v i t i e s which a r e e c o n o m i c a l l y more pow e r f u l dominate t h e market. C e n t r a l o f f i c e a c t i v i t i e s a r e growing and " c o l o n i z i n g " p r e d o m i n a n t l y r e s i d e n t i a l a r e a s . As r e n t s r i s e , due t o t h e r e v a l u a t i o n , r e s i d e n t s a r e f o r c e d t o move o u t o f t h e d i s t r i c t . The space r e q u i r e m e n t s o f most o f f i c e work can be s a t i s f i e d v e r y w e l l by r e m o d e l l i n g f o r m e r r e s i d e n t i a l accommodations. T h i s p r o c e s s may c o n t i n u e u n t i l f i n a l l y t h e c o l o n i z e d a r e a p r o v i d e s s u f f i c i e n t a t t r a c t i o n s t o e n courage i n v e s t m e n t by l a r g e c o r p o r a t i o n s . T h i s o f t e n i n v o l v e s c o n s t r u c t i o n o f p u r p o s e - b u i l t o f f i c e s p a c e by d e m o l i t i o n o f t h e c o n v e r t e d r e s i d e n t i a l p r o p e r t i e s . A t t h e same t i m e , new r e s i d e n t i a l developments on the f r i n g e o f t h e town a r e growing to accommodate a l l the people who a r e employed i n t h e c i t y . As a r e s u l t , t h e r e i s a s i g n i f i c a n t number o f commuters who l i v e i n the o u t s k i r t s o f t h e community and work i n t h e c i t y , t h u s c r e a t i n g abandoned c i t y c e n t r e s a t n i g h t and dead suburbs i n d a y t i m e . - 33 -This d i s t i n c t separation of functions (working, l i v i n g , recreation) is only possible with the l i nk of transportat ion. The energy consequences of th i s separation are far reaching. In most cases, home and workplace are connected by the use of pr ivate.cars , leading to enormous squandering of f u e l , heavy t r a f f i c congestion, po l lut ion and related problems. Planners are invest igat ing the e f f i c i ency of the present transportation system. The fuel shortage revealed the vu lne rab i l i t y of th i s sytem and ca l led into question the current i n t e r -re lat ionsh ip between the locat ion of work, le i sure and l i v i n g . S ign i f i cant r e l i e f from the problem w i l l only be achieved i f , as part of the metropolitan renewal scheme, some of the motor t r a f f i c i s obviated by the construction of dwellings close to o f f i ces and vice 19 versa. Controls imposed by public planning boards can also a f fect o f f i c e locat ion. Land use contro ls , zoning and. by-laws are used to guide spacing, deta i led l oca t ion , density, height, appearance and other aspects of o f f i ce development. In addit ion to the i r ind i rect ef fects on the locat ion patterns of o f f i c e s , planning controls can also .affect the a b i l i t y of o f f i c e developers to react to market requirements for space.' Therefore, the role of the developers should not be underestimated. However, they w i l l only provide space where a certain p ro f i t on the investment can be rea l i zed. - 34 -An important feature of a c c e s s i b i l i t y is the proximity of restaurants, hotels, shops and short-time recreational f a c i l i t i e s to o f f i ce s . This helps to a t t ract and keep valuable s t a f f ; i t also provides addit ional a t t rac t ion to out-of-town v i s i t o r s . Again the wfdest'range, of ' these 'support f a c i l i t i e s are found in the c i t y centre. 3.3. Location Factor: Communication Off ice locat ion i s much more a product of information flow than of the movements of goods. As shown e a r l i e r , there was a steady increase in the introduction and use of new. communication techniques which allow further concentration of o f f i ce space in the Central Business D i s t r i c t (CBD). This process i s a function of the need for contacts and exchange of information between the people who perform increasingly special ized a c t i v i t i e s in the c i t y . Communications between o f f i ces i s achieved e i ther through information channels or face to face. The former way is pa r t i cu l a r l y important for transmiting data for routine o f f i c e work. Theoret ica l ly , communication makes a considerable part of a l l o f f i c e a c t i v i t i e s independent of a spec i f i c locat ion. Therefore, i t should be possible to escape the hustle and bustle of the c i t y centre and to relocate o f f i c e a c t i v i t i e s out of the c i t y centres in suburban areas. There i s a reason why corporations do not adopt such a po l i cy , despite the numerous communication media ava i lab le . At the higher level of decision-making in o f f i c e s , face-to-face communication is considered extremely,important, because i t involves problem so lv ing, - 35 -20 inquir ies and negotiations. Often in such a c t i t i v i e s , i t i s necessary to know several persons' att itudes on many issues in order 21 to decide on an act ion in a complex s i tua t ion . Therefore, the more frequently personal contacts are required, the more central the location of an o f f i c e has to be to minimize cost. The value of the executive time is the most important cost fac to r , i t i s not the da i l y travel-to-work time of the numerous c l e r i c a l s t a f f . Executive e f f i c i ency is achieved by maximizing the amount of time for meetings and decision-making and minimizing the time to travel and to handle repet i t i ve communication work. This fact i s under-22 l ined in a study by Stewart which shows that 43% of a manager's time is spent in person-to-person meetings, compared to 6% on the telephone. Although personal contact current ly seems to be a dominant factor in o f f i c e l oca t ion , i t has to be remembered that a growing proportion of contacts between of f i ces involves non-personal information channels. As soon as the potential of the ava i lab le communication tools i s r ea l i zed , many more personal contacts w i l l be made v ia communication systems. This w i l l reduce the energy demand for transportation and l i b e r a l i z e o f f i ce locat ion. - 36 -4. STRATEGIES IN THE URBAN CONTEXT Opportunities for energy^conservation in the urban context are more s i gn i f i can t than those achievable by the design of indiv idual bui ldings. When t ry ing to improve the energy e f f i c iency of o f f i c e bui ld ings, i t i s therefore necessary to consider the potential for improvements of the o f f i ces in the larger urban context. Land use patterns have a substantial e f fect on energy consumption. The massive energy requirements for transportation is a d i rec t consequence of the current land use pattern, characterized as "urban sprawl." Cheap and p len t i f u l energy supplies in the past have permitted several decades of urban development to ignore the energy consequences of land use decisions. Most of the energy used in transportation i s used by the private car. In terms of energy, the automobile is a very i n e f f i c i e n t way of t r a v e l l i n g , as Table 2.2. shows: 23 Table 2.2.: Speci f ic Energy Consumption According to Mode of Transport Mode of Transport Meal 100 Person-km Energy Supply Rail Transport: E l e c t r i c locomotive 15.4 e l e c t r i c i t y Diesel locomotive 28.7 diesel Sub-way 11.2 e l e c t r i c i t y Urban T r a f f i c : Bus .18.2 diesel Trol1ey-bus ' 44.8 e l e c t r i c i t y Automobiles .51.8 gasoline A i r t r a f f i c 166.6 av iat ion fuel - 37 -Much e f f o r t i s now being spent on improving the energy ef-f i c iency of the automobile. However, much more could be achieved by changing some c i t y planning po l i c i e s , so as to reduce the to ta l amount of commuting required, and to encourage the use of public transportat ion. 4.1. Decentral ization Ult imately, the trend to decentra l izat ion w i l l leaid to a decl ine of the large central c i t y . The return to a more dispersed settlement pattern, with attendant decentralized employment s t r u c t u r e , ^ becomes possible when the dispersed settlements are located l i n ea r l y along the main transportation routes. This allows a higher l inear density of development that would make public transportation a t t rac t i ve and economical. Figure 2.3.: Decentralized Land-Use Model TtANSPOfcTATlON L A N D U S E P A T T E R N PEXAIL-. PL-M S E C T I O N - 38 -Beside a l inear transportation and d i s t r i bu t i on system there would remain a large number of dispersed open, undeveloped areas for agr icu l ture and recreational use. The d i rec t proximity of res ident ia l population to food production could contribute to a substantial reduction of the energy consumption that goes into preparing and transporting foodstuffs, garbage and sewage could be l o c a l l y processed and returned without further energy expenditure 25 to the adjacent land. The main advantage of th i s proposal l i e s in the fact that a high density is maintained along a narrow s t r i p , as d i s t i n c t from a low density spread across a wide area. Therefore, close r e l a t i on to the countryside and good a c c e s s i b i l i t y to work and to services are maintained in contrast to today's land use pattern. As a consequence, the trend to monofunctional c i t i e s , where working, l i v i n g and recreation are separated, would be reversed. The c i t i e s would not only be decentral ized, but also changed to smaller units which contain a l l necessary functions in a balanced proportion. 4.2. Mixed Development Mixed use developments o f fer potential for creative combinations of d i f fe rent land uses within a s ingle project such as including recreational and res ident ia l f a c i l i t i e s in a commercial complex. Such integration of land uses would reduce the need for t r a v e l , plus o f fe r opportunities for increased e f f i c iency in energy systems through the u t i l i z a t i o n of waste heat and other sources. - 39 -Depending on density, comprehensive planning could provide goods and services to residents within a short distance and also make o f f i c e jobs ava i lable that could be f i l l e d by people who l i v e nearby. Thus, commuting could be cut substant ia l ly . Separation of uses has meant that many buildings are used for only one purpose, often during only part of the day or night. Commercial buildings often s i t vacant for many hours. These bui ldings. although vacant, must be heated, cooled and l ighted to some extent. "Doubling up" of u se sw i th in one structure could save energy and materials that would otherwise be necessary in bui lding two structures 26 instead of one. Mult ip le use buildings are now being developed. Figure 2.4.: Mixed Developement 27 PARKIN*. i , A P A R T M E N T l \ ,1 APT: 1 X t IAPT. Vt. OFFICE , OFFICE , , SHOPS 1 n .s*-. 1 APT. .iv 1 APT. \ . I OFFICE OFFICE IMALU I SHOPS P A K K I K I 4 r - 40 -A community centre, for instance, could be combined with an o f f i c e bu i ld ing, shopping f a c i l i t i e s and apartments. It becomes then possible to take advantage of the uneven building.loads • caused by d i f f e ren t , but complementary occupancy patterns. The surplus heat of the o f f i c e bui lding can be used for heating or preparation of domestic hot water in the apartments. This so lut ion would not cause any technical problems, but rather involve an e f f i c i e n t energy management for the whole s i t e . Figure 2.5. i l l u s t r a t e s the complementary power demands of a combined commercial/ res ident ia l development. Figure 2.5.: Power Demand P r o f i l e of a Commercial/Residential po Developement  COMMERCIAL RESIDENTIAL u Ul z IU 1 4 - 6 8 Io II 4 8 IO 12. TIME - 41 -4.3. Implications The strategies of decentral izat ion and mixed use would not only reduce the tota l amount of energy consumed in such an urban planning scheme, but they would also change the qua l i t a t i ve aspects of the energy production, d i s t r i bu t i on and consumption. The use of " so f t energy technologies" would be enhanced. In contrast to the high technolog ical , centra l ized path, the soft energy path advocates a.renewable, diversed, small-scale and low 29 technological energy future. However, the implications of the proposed decentral ized communities go well beyond the level of energy use. This concept w i l l have socia l and p o l i t i c a l implications as we l l . As the large sca le, cent ra l l y -cont ro l led c i t i e s are broken up in smaller s e l f -s u f f i c i en t un i t s , more personal involvement by people is allowed. Opportunities for democratic local planning processes are created. The growing concern of people for the i r immediate environment could be d i r e c t l y implemented in p o l i t i c a l decis ions, that are based on qual i ty rather than quantity. This i s an important step toward the conserver society. - 42 -5. NOTES 1. E. Rausch, Pr inc ip les of Off ice Administration (Columbus: Men" 11 , 1964), p. 4. 2. W.T. Morgan, The Growth and Function of the Central.Business D i s t r i c t (London:, 1960) 3. Regional Plan Association New York, quoted in R.S. Armstrong, The Off ice Industry: Patterns of Growth and  Location (Cambridge: MIT-Press, 1972), p. -9-.•', 4. Michel Croz ier, Le Monde des Employees de Bureau (Par i s : Edit ion du Seu i l , 1965). 5. Regina S. Armstrong, op. c i t . , p. 10. 6. V ictor R. Fuchs, The Service Economy, National Bureau of Economic Research. (New York: Columbia Univers ity Press, 1968). 7. C.W. M i l l s , White Col lar (Oxford: Oxford Univers ity Press, 1951), p. 192. 8. Canada has now reached th i s l a t t e r stage. In 1971, 48% of a l l Canadian workers were non-manual workers. This number is s t i l l s tead i ly i n -creasing. See P.W. Daniels, Of f ice Location (London: Bel l & Sons, 1975). 9. Richard G. S te in , Architecture and Energy (New York: Anchor/ Doubleday, 1978), p. 15. 10. Peter W. Daniels, op. c i t . , p. 221. 11. Maximilian G. Meyer, Values in Architecture (Master Architectura l Thesis, Univers ity ot B r i t i s h Columbia, 1979), p.. 124. 12. D.M. Smith, Industrial Location: An Economic Geographical Analysis (London: Wiley and Sons, 1971). 13. Regina B. Armstrong, op. c i t . , p. 27. 14. City of Vancouver, Information and S t a t i s t i c s : Off ice Space Demand in Downtown Vancouver: 1961-1980. Summary Report #9 (Vancouver: Vancouver Planning Department, August 1973) p. 12. 15. P. Cowan, The Of f ice: A Facet of Urban Growth (London: Heineman, 1969), p. 104. 16. Richard G. Ste in, op. c i t . , p. 52. - 43 -17. R.M. Haig, Major Economic Factors in Metropolitan Growth and Arrangement (New York:, 1927). 18. Peter Chapmann, Fuels Paradise (Harmondsworth: Penguin, 1975), p. 220. 19. Reinhold Hohl, Off ice Bui ld ings: An International Survey (New York: Praeger, 1968), p. 6. 20. Stephen Mull i n , "Planning Off ice Space: Some Notes on A c t i v i t y , " in Planning Off ice Space, ed. F. Duffy and J . Worthington (London: The Architectura l Press, 1976), p. 21. 21. E. Dale, Modern Management Methods (Harmondsworth:•Penguin, 1966) p. 51J 22. Richard Stewart, Managers and Their Jobs (London: Macmillan, 1967), pp. 24-69. 23. Ueli Rothi "The Impact of Settlement Patterns on Low Temperature Heating Supply Systems, Transportation and Environment," in Energy Use Management, proceedings of the International Conference in Tucson, Arizona 1977. Volume 2 (New York: Pergamon Press, 1977)', pp. 407-418. 24. Gerald Manners, The Office in Metropolis: An Opportunity for Shaping Metropolitan America, Working Paper No. 22, (London: Univers ity College, 1973), p. 40. 25. Ph i l i p Steadman, "Energy and Patterns of Land Use, " ' i n Energy Conservation Through Bui lding Design,.ed. D. Watson (New York: McGraw-Hill, 1979), p. 259. 26. Urban Land In s t i tu te : /'Mixed^Use Developments," Technical Bu l l e t i n No. 71 (Argonne, I l l i n o i s : Urban Land In s t i tu te , 1976). 27. Dimitr i Procos, Mixed Land Use (Toronto: Dowden, 1976). Project Hazel ton Lanes in Toronto, p. 112.. 28. Richard E. Holz, "Potent ia l Energy Savings in Commercial/ Residential Communities Based on Integrated Systems Design," Heat Transfer in Energy Conservation, winter annual meeting of ASME, At lanta, Ga., November 27-December 2, 1977 (New York: ASME, 1977), p. 28. 29. Amory Lovins, Soft Energy Paths (Cambridge, Mass.: Bal l inger Publishing Company, 1977), p. 39. - 44 -CHAPTER III: THE INDIVIDUAL OFFICE BUILDING 1. INTRODUCTION 2. BUILDING SHELL 2.1. Form 2.2. Materials 3. BUILDING LAY-OUT 3.1. History of Daylighting 3.2. Standard Lay-Out Pract ice 3.2.1. Ce l l u l a r Off ices 3.2.1.1. Character i s t ics and Advantages 3.2.1.2. Disadvantages 3.2.2. Open Plan Offices 3.2.2.1. Character i s t ics and Advantages 3.2.2.2. Disadvantages 3.2.2.3. Energy Implications 3.3. New Lay-Out Concepts 4. THE WORKSTATION 5. NOTES - 4 5 -CHAPTER III : THE OFFICE BUILDING 1. INTRODUCTION The growing importance of the service sector in.the i ndus t r i a l i zed countries has led to a profound change of c i t i e s . At the level of the indiv idual commercial bui lding a para l le l change occurred that was characterized by the increased rate of change in the development!of new bui ld ing processes and mater ia ls , the technological innovations in bui lding systems and the increasing " r a t i o n a l i z a t i o n " ' o f "building form, that was expressed in the bui lding s h e l l , the o f f i c e lay-out and the indiv idual work places. The resu l t of th i s development i s the growing energy demand to operate and maintain our b u i l t environment. Energy i s used in bui ldings for various-functions of comfort, u t i l i t y and convenience. The tota l energy consumption i n ' a commercial bui ld ing can be attr ibuted to the Figure 3.1. Breakdown of Off ice Energy Use £ ; ^ ' - 46 -fol lowing bui ld ing systems: - heating - cool ing - l i gh t ing - more energy around in the bui lding (fans, pump) - power for equipment - domestic hot water preparation The order of magnitude of these factors are an approximation only and vary in any indiv idual bui lding according to c l imate, function of the bu i ld ing, operation and design of the bu i ld ing. The influence of the climate is i l l u s t r a t e d in Figure 3.2. A 3 study by the National Bureau of Standards gives the energy consumption for an o f f i c e bui ld ing located in cold climate and for the ident ica l bui lding i f located in a warm cl imate. Heating i s the s ingle largest user of energy for the o f f i ce bui lding in cold c l imate, the amount for cooling i s small. In the warm cl imate, however, the energy used for heating has decreased and cooling requires the dominant amount of energy. It i s interest ing to note that the energy expenditure for l i gh t ing purposes is independent of cl imate. F I 9 U R E 3 - 2 - Energy Use for an Off ice Building in Warm and Cold Cl imates 4 4 EUECTt, EfiUlf>. 5 HOT WATER I HEATING Z LI4HT1VW, 3 C O L O CLIMATE OFFICE I0fc,ooo BTU /ft*- /yg \jUA-fcM CLIMATE OFFICE (,7,000 &Tu/f{i/yg. - 47 -The breakdown of energy use in o f f i c e s , as presented in the l a s t f i gure , i s useful fo r ident i fy ing the major areas of potential energy e f f i c iency improvements in o f f i c e bui ldings. In a typ ica l o f f i c e bui ld ing of the early '70 ' s heating and l i gh t i ng are the main targets for energy savings, whereas the energy use for fans, pumps and the l i k e to d i s t r i bu te the energy in the bui lding are less important. However once the heating and l i gh t i ng system are improved by e f f i c i ency measures, the d i s t r i bu t i on of the energy within the bui ld ing becomes much more c r i t i c a l . Further energy conservation measures therefore would have to concentrate on the reduction of the energy used for fans, pumps, etc. This re lat ion i s shown in Figure 3.3. i 9 u r e 3 - 3 - Relative Effect of Energy Conservation Meas BEFORE AFTER * FANS , POMPS 5 HOT WATER I HEATING 3 COOLING E N E F U V U5E BEFOR£ ANP AFTER EFFICIENCY IMPROVEMENT The fol lowing sections give an overview of the most recent development of the o f f i c e bu i ld ing; current design pract ices ar mentioned and the major energy implications are i d e n t i f i e d . - 48 -2. BUILDING SHELL  2.1. Form The recent development in o f f i ce bui ld ing design was characterized by an enormous quant i tat ive growth of o f f i c e space as a response to the general increase of the service sector. Figure 3.4. shows the growth of o f f i ce f l oo r space from 1930 to 1970 and the projections for the next two decades in the United States. Figure 3.4. Estimated National Inventory of Off ice Floor Space 5 v * 1 > / / / / ^ ^ ^ ^ ^ ^ . , ^ 1 l l - I W 3° 1° % Even'when the future growth i s questionable, the graph indicates c lea r l y the trend within the las t decades. What i s even more important is the fact that the s ize of the indiv idual o f f i c e buildings has increased. The average s ize of a large o f f i c e bui ld ing in downtown Vancouver constructed in 1960 was 9000 m 2. In 1979 the average s ize increased to 20,000 m 2. Part ly th i s has been a - 49 -consequence of the appl icat ion of the new bui ld ing technology which has made such spaces useable. Part ly i t has resulted from arguments that s ize and openness encourage communication and permit f l e x i b i l i t y ^ , and part ly i t goes back to the simple philosophy "the bigger the better " ? . The fast development of.such large buildings does not allow a design that s a t i s f i e s more than the funct iona l , economical and i n s t i t u t i ona l requirements. The resu l t i s that quant itat ive rather than qua l i t a t i ve aspects dominate o f f i ce building design. The increase in volume of o f f i c e buildings was mostly connected with the trend to higher bui ldings. Economic pressure and l i b e r a l i z ed zoning laws allowed the development of t a l l bui ld ings. The ea r l i e s t examples o f t a l l buildings were constructed in Chigaco in the 19th century.. The 10 storey high buildings had thick masonry bearing walls that were tapering upwards. Improvements in bui lding technology brought the steel framed construction that allowed further height (see Table 2.1.). The metal skeleton represented a major step forward in the construction of the t a l l o f f i c e bui ld ings, because the walls could be suspended from the frame and be of uniform thickness throughout. This was the o r i g in of the curtain wal l . ? At the same time the development of the passenger elevator provided rapid transport within the t a l l structures and rea l i zed the potential set up by the improved construction technology. This event inspired the ent i re ve r t i ca l development of the North American c i t y and marked the beginning of the skyscrapers. Further structural innovations were introduced af ter World War II : framed-tube and truss-tube structures allowed bui lding heights - 50 -up to 140 s t o r e y s , as F i g u r e 3.5. shows. F i g u r e 3.5. S t r u c t u r a l Systems and B u i l d i n g H e i g h t However, t h i s p r o g r e s s i n b u i l d i n g t e c h n o l o g y was made a t the expense o f t h e o v e r a l l e f f i c i e n c y o f t h e b u i l d i n g . F i g u r e 3.6. i n -d i c a t e s t h a t t h e demand f o r s t e e l i n c r e a s e s e x p o n e n t i a l l y w i t h i n -c r e a s i n g b u i l d i n g h e i g h t , due t o the added wind l o a d s . F i g u r e 3.6. S t e e l Demand f o r T a l l B u i l d i n g s 1 0 3 <> W _FOB. rt-"" 20 40 60 80 100 NO. OF STORIES (FIVE BAY FRAME) - 51 -The implications o f t a l l " buildings on energy use are substant ia l . A considerable amount of energy i s used to run addit ional monitors, pumps and fans in order to provide the necessaryservtces: in the upper f l oo r s . In the lower f loors an enormous amount of space i s required to accommodate the necessary elevators, duct shafts, pipe shafts and equipment rooms, serving the upper part of the bu i ld ing. The re la t ion of useable o f f i c e space to the tota l f l oo r area i s sharply [decreasing in t a l l o f f i c e bui ld ings, as the service and the c i r cu l a t i on area increase on the Tower f l oo r s . This re la t ion can be observed in the f l oo r plans of the IBM bui ld ing in Chicago: more than 30% of the lowest f loor s are given up for serv ic ing and c i r c u l a t i o n , whereas the top f l oo r uses about 16%. Not only i s the space u t i l i z a t i o n i n e f f i c i e n t , but the space not d i r e c t l y useable for o f f i c e purposes increases the overal l volume of the bui lding and contributes to the energy require-ment for heating and cooling the space. - 52 -- 53 -2.2. MATERIALS The o f f i c e bui lding in the 19th century had loadbearing brick walls with small windows to provide some dayl ight. With the innovation of the steel frame construction, concrete and steel gradually became the dominant building mater ia ls. The function of the wall as one of load-bearing and cont ro l l i ng the internal environment became separated with the introduction of the skeleton and the cur ta in -wa l l . The window area increased s i g n i f i c a n t l y , and the opaque wall diminished in importance. I n i t i a l l y the windows expanded hor izonta l l y to long window bands. Then the s ingle window, completely freed from structura l functions, became a complete window wal 1. This evolution can be observed in the design work of le Corbusier, as presented in Figure 3.8. It also emerges c l ea r l y out of the fol lowing quotation: ". . . today as we possess steel and reinforced concrete...nothing these days prevents us from opening toward the solar rays, not a mere f r a c t i o n , but 100% of a facade This new freedom gave enormous p o s s i b i l i t i e s for f a n t a s y . . . " ^ Figure 3.8.: Development of Window 12 Hi m i HI n Indeed the f l o o r - t o - f l o o r window enriched architecture with a psychological sense of freedom, with unrestr icted views in and out as well as with a var iety of exc i t ing spat ia l re lat ionsh ips . But i t i s evident that th i s transformation created some new problems, among those the exposure of the glass areas to solar radiat ion and winter cl imate. Both have a s i gn i f i can t e f fect on the energy consumption in o f f i ce bui ld ings. The func t i ona l i s t movement, of which le Corbusier was a representative, held that the bui lding form should d i r e c t l y r e f l e c t the internal processes which i t was housing. "Truth to bui ld ing funct ion" symbolized the design approach which tended to override external environmental considerations. The emphasis in design was from the inside of a bui lding outwards ("form follows funct ion " ) , with l i t t l e emphasis of developing the form most e f f i c i e n t in modifiying the.externa l ;_c l imateJ 3 However the or ig ina l functional concepts were s t i l l based on some environmental considerations, as for instance the path of the s u n J ^ i t was in the fol lowing development of the Modern Movement architecture that the wel l - intent ioned ideals became distorted and s imp l i f i ed . Beauty became synonymous with a s ty le that resulted from a mechanistic assemblage of room functions, s t a i r towers and ... service shafts a l l clad with a uniform skin. The glass curta in-wal l was used on a l l facades of a bui lding regardless to o r ientat ion . The or ig ina l function of the bui lding shel l as a c l imat i c modifier was passed on to the mechanical equipment at the expense of a high energy input to operate such systems. This tota l rel iance on mechanical systems created a f u l l y a r t i f i c i a l l y control led internal environment. - 55 -The remaining function of the bui ld ing skin is merely that of sealing the i n te r i o r hermetically from the exter io r . Contemporary o f f i ce buildings tend towards a standardization of bui lding form and materials> such that they conform to an " International S t y l e . " This " s t y l e " i s dominated by an esthet ic of simple rectangular forms and a consistent disregard for var iat ions of the external cl imate. The bui ld ing skin i s l ightweight, often poorly insulated and used on a l l elevations of the bui lding with l i t t l e regard for excessive solar radiat ion gains or heat losses. In many cases the bui lding has to be cooled on one side while being heated on the o t h e r J 5 The change of the bui ld ing form in the past decades (was attended by the development of a new family of bui lding materials. Special glazing types, p la s t i c and aluminium have replaced the t rad i t i ona l materials, often without an adequate understanding of the i r l i k e l y consequences. In terms of energy these new materials require much more energy input for the i r production than the conventional materials. Aluminium i s a very high energy intensive mater ia l , that requires f i ve times more energy to manufacture than s t e e l . ^ - 56 -3. BUILDING LAY-OUT The h i s t o r i ca l development of the o f f i c e lay-outs i s c lose ly related to the technological improvements in the f i e l d of a r t i f i c i a l l i gh t i ng and mechanical equipment. This can be shown with a short-review of the ro le of dayl ighting in -of f ice- bui ldings. 3.1. History of DayTighting I n i t i a l l y most o f f i ce space was natura l ly l i t by the l i g h t 1 that was avai lable through operable windows. Daylight was both ' necessary and desireable. The absence of dayl ight was considered to be a health hazard.18 A profound psychological value was att r ibuted to dayl ight and to the fee l ing of proximity to the outdoors, espec ia l ly in densely planned o f f i ce areas. Zoning regulations ca l led for spacing buildings or for a l i m i t of the i r height in order to secure adequate dayl ight ing. A c la s s i c example are the zoning regulations of New York, that prescripted a setback of the upper f loors above a certa in height to allow sun and dayl ight to penetrate the street c o r r i d o r s B u i l d i n g codes asked for a minimum fenestration area in repect to room size and p a r t i a l l y established standards for dayl ighting Using t rad i t i ona l practice and economic l im i t s to c e i l i n g height the resu l t ing depth of o f f i ces that could be day l i t was about 6.00m. Studies confirmed that overal l sa t i s fac t ion with dayl ight declined considerably in o f f i ces deeper than 6.00m, due to increased on complaints of i n su f f i c i en t l i g h t . The 6.00 deep o f f i c e space generated a typ ica l bui lding depth of about 12.00 to 15.00m. The glazing area of such day l i t bui ld ing was about 50% of the facade. - 57 -Figure,3.9.: Shallow Dayl i t Off ice Space Section Day!ight \ V Daylight - Curve \ Examples mm BUS! iy't<aI'!'YfVt'iW*V«^a! • • • i i • i • • * • • t i • t • • v t • I « T ' r • t • r * \,K-rri.r^b. r^i xrrb. nrK .<nrb. .c^ r?. -hr?. rr^ .-fr?. .6TJ. rhr. . i r 1S0BI - 58 -Figure 3.10.: Medium Deep Off ice Space Section Light - Level /Total ^ ^Permanent Supplement-ary A r t i f i c i a l Light ,Day1ight - i 1 r -2. t - T -Example - 59 -Figure 3.11.: Deep Off ice Space (Permanently A r t i f i c i a l l y L i t ) • "IP »T" i a a i ia a i 14. £ J 1181 ' -/ 1 \ / l \ / 1 \ / \ / 1 \ Section Light - Level T 1 -I > 3.So m Total - i r •4 A r t i f i c i a l Light Daylight - i r -10 -n * 12, m - 60 -The improvement and p ro l i f e r a t i on of a r t i f i c i a l l i g h t sources ult imately manifested i t s e l f in the concept of Permanently Supplementary A r t i f i c i a l l y L i t Inter iors (PSALI). PSALI was introduced after World War II to improve the standard of v isual environment -im o f f i ces by producing a more even grading between the front and back of spaces. The area close to the windows r e l i ed upon dayl ight, whereas the more distant portion of the o f f i ce space was a r t i f i c i a l l y supplementary l i t . It had the major economic advantages of extending the depth of useful space to 9.50m. The resu l t ing slab bui ld ing design for PSALI would have an overal l depth of approximately 15.00 to 24.00m, as Figure 3.10 shows. The concept of PSALI was not widely adopted. Further/progress in environmental design resulted from develop-ments in mechanical and e l e c t r i c a l systems. The e l e c t r i c a l l i gh t i ng system and the mechanical systems were now able to create a f u l l y a r t i f i c i a l l y control led environment. The potential of low operating costs and increase in design l i gh t ing levels combined to produced Permanently A r t i f i c i a l l y L i t (PAL) bui ld ings, presented in Figure 3.IT. Although buildings are s t i l l extensively clad in glass and, to an extent, capable of using day l ight, because of the h i s t o r i c a l l y cheap energy prices the a r t i f i c i a l l i gh t i ng systems are operational throughout the day regardless of the avai lable outside i l l uminat ion . As a r e su l t , since o f f i ce design does not consider dayl ight as the p r inc ip le means of l i g h t i n g , the r e s t r i c t i o n of o f f i ce depth no longer holds. Economic pressures have led to the development of the deep plan o f f i c e s , that are permanently a r t i f i c i a l l y l i t throughout. Research has .shown : that i t was not the actual daylight that was important to the occupants of o f f i ce bui ld ings, but jus t the fact to know that there are windows 01 in the 'bu i ld ing . Windows are now considered pr imar i ly for the i r , view potent ia l . The short analysis of dayl ighting shows the systematic de-emphasis of the window for l i gh t i ng purposes and a steady trend toward deeper o f f i ce spaces. This i s well compatible with the general growth of o f f i ce a c t i v i t i e s and the increase in the s i t e of o f f i ce bui ld ings. However th is development was only possible through the improve-ment of the internal environmental control systems and "an attendant increase in energy use. This can be shown in the energy consumption for l i gh t i ng in an o f f i c e bu i ld ing. Whereas energy expenditures for l i gh t ing were i n s i gn i f i c an t in largely d a y l i t pre-war o f f i c e , a r t i f i c i a l l i gh t i ng in large modern o f f i c e i s frequently among the largest users of energy.21 The e f fect of a r t i f i c i a l l i gh t ing on energy use i s twofold: energy i s used d i r e c t l y for i l luminat ion as well as for removing the excessive heat generated by the l i g h t s . This i den t i f i e s l i gh t i ng c l ea r l y as one of the most important aspects for energy conservation in o f f i c e bui ld ings. 3.2. Standard Lay-Out Practice Current lay-out design practice uses predominantly medium to deep o f f i ce space. Shallow o f f i ce space i s considered as uneconomical. The/imain reason deals with the potential to accommodate d i f fe rent typologies of o f f i c e working environment: - c e l l u l a r o f f i ces or - open plan o f f i ce s . i - 62 -The two typologies d i f f e r in the i r dimensional cha rac te r i s t i c s , as well as in the way they u t i l i z e and characterize space. 3.2.1. Ce l l u l a r Off ices 3.2.1.1. Character i s t ics and Advantages The t rad i t i ona l form of o f f i ce lay-out i s the c e l l u l a r o f f i c e . It i s t y p i c a l l y found in narrow ribbon buildings of about 12.00 to 15.00m depth. These buildings are characterized by one or more corr idors with many small rooms leading o f f them. The space for o f f i c e use i s 50 to 60% of the tota l f l oo r area. The typ ica l occupancy of c e l l u l a r o f f i ces i s between 1 and 4 persons, according to the rank of the workers and the size of the rooms. The s ize of the rooms i s a function of the basic bui ld ing module and the window mul l ions, because any part i t ions for subdivisions are multiples of the module. Usually space standards and therefore prestige are assigned according to the number of windows in an o f f i c e . The minimum room width i s 2.40m (often two mullion spacings). The depth does not exceed 6.00m. The resu l t ing f l oo r area of c e l l u l a r o f f i ces would therefore be between 15.00 and 40.00 m 2. Figure 3.12. Ce l l u l a r Off ices B c D E r . • c , :1 c — i—i — Z' : c c c • c LJ • D 1 - 63 -By de f i n i t i on c e l l u l a r o f f i ce s are completely enclosed by walls and fenestrat ion. Since the par t i t ions prevent overlooking and can prevent noise disturbances, d i s t ract ion i s minimized and they o f fe r maximum privacy. Often, however, complete i so la t ion i s not desired and doors are l e f t open to prevent the fee l ing of claustrophobia and to secure a connection to the other o f f i ce workers. 2^ Due to the shallow room depth c e l l u l a r o f f i ces re ly pre-dominantly on day l ight ing, i f located on the perimeter. They are usually designed for indiv idual environmental cont ro l . The l i g h t can be switched on and off and windows can be opened according to individual needs for natural ven t i l a t i on . Such controls are easy to handle and are understood by the user. This design approach re f l ec t s the at t i tude that physical comfort i s not uniform, but a matter of indiv idual preference. 3.2.1.2. Disadvantages On the other hand there are disadvantages of c e l l u l a r o f f i c e s . Communication and work flow can be impaired, because departments tend to be fragmented, often impairing operational e f f i c i ency . Several people sharing a small o f f i ce are in permanent close contact, contact that may not even have the basis in work needs and therefore lend to personal problems. Not everybody who requires a private o f f i ce is a l located one; and the shared o f f i ces can create poor conditions for mental work. The current need for rapid organizational change is in c o n f l i c t with the idea of non-f lex ib le c e l l u l a r o f f i ce s . Reorganizations are taking place constantly and require a red i s t r ibut ion of space. - 64 -Uninterrupted modular space with modular par t i t i on ing was therefore introduced. But there movable"partition, systems, which have been used for many years, are not t r u l y f l e x i b l e . The actual cost of moving a pa r t i t i on i s so high that the " f l e x i b l e 1 ' par t i t ions are in fact very rarely moved. 2 5 A l terat ions in the lay-out require extensive planning and are usually only undertaken when the whole space i s remodelled. Despite growing inconvenience the or ig ina l arrangement i s considered sacrosanct, because minor changes are not possible. Another problem i s the sound proofing of par t i t ions for reasonable cost. 3.2.2. Open Plan Offices 3.2.2.1. Character i s t ics and Advantages The concept of open plan 'off ices deals with lay-outs without using wall pa r t i t i ons . It i s based on the theory that suggests that par t i t i on ing i s unnecessary in o f f i ce s and even detrimental to ideal o f f i c e functioning. Open plan i s the general term for a whole var iety of spec i f i c ways of open o f f i ce planning. Open plan o f f i ce s emerged in North America ear ly in th i s century. Wherever the exchange of information and the requirements of production ca l led for group work and the concentration of employees or the cont iguity of d i f fe rent departments, large scale i n te r i o r s known as open spaces were used. In Europe, however, open plan off ices ' were not used unt i l 1958, when a German group introduced t h e i r , spec i f i c concept of open plan, the o f f i ce landscap ing. 2 6 This lay-out is characterized by the highly i r regu lar arrangement of the furn i ture and a f u l l y control led a r t i f i c i a l environment. Figure.3.13 shows both approaches to open o f f i c e planning. - 65 -Figure 3.13. Open Plan Off ices A) "American" Open Space B) . Off ice Landscaping Open plan lay-outs are found in compact buildings with a depth of at least 20.00m. The structural gr id has a minimum size of about 7.20m. Smaller distances between the bearing supports resu l t in visual and functional fragmentation of work areas. They would also make e f f i c i e n t sublett ing more d i f f i c u l t . In a general sense, open planning i s r e l a t i v e l y easy to achieve in large, open spaces with a minimum of obstructions and i r r e g u l a r i t i e s . In small to medium sized open plan o f f i ce s c i r cu l a t i on and service spaces are perferably placed at the edges of the space. Beside the better space u t i l i z a t i o n th i s offers also an opportunity for thermal zoning. In large areas, measuring more than 3800m , i t i s desirable to l i m i t unbroken distances to 38.00 or less in at least one d i rect ion . to avoid endless depressing i n t e r i o r views. Central cores or rectangular proportions of the lay-but are most often used. 2? . - 66 -The compactness of buildings and the open plan lay-out allow a more e f f i c i e n t space u t i l i z a t i o n than in c e l l u l a r o f f i c e s : the avai lable o f f i ce space i s 70-80% of the to ta l f l oo r area. Besides permitting a more intensive use of avai lable space, open plan also allows greater f l e x i b i l i t y of use in so far as i t permits a l l those organizational changes that ar ise with the development of any business. Open plan i s well suited to accommodate a l l the recent innovations in business organization techniques, that re ly on a broadly movable environment. Communication i s the-basis for the a l l ocat ion of the indiv idual workstations. The close and unobstructed in ter re la t ionsh ip of the workstations provides extreme ease of communication, a good work flow and better supervis ion, which leads to c loser teamwork and fewer bureaucratic impediments. 3.2.2.2. Disadvantages The main objections to open planning i s the lack of privacy in rooms inhabited by a large group of people, the d i f f i c u l t y of doing work that requires a high degree of concentration, and the lack of environmental d i s t i n c t i on . Recent research confirms that o f f i ce workers have a natural desire for t e r r i t o r y i d en t i f i a b l e as t he i r no own, and that i t s denial leads to feel ings of unease and h o s t i l i t y . This fact i s generally more d i f f i c u l t to respect in open plan than i t would be in c e l l u l a r o f f i ce s . The t e r r i t o r y in open plan can be marked by fu rn i tu re , plants and spacing between workstations. However the use of the important elements of natural .1;Sight and views to the outdoors i s not avai lable and r e s t r i c t ed ' t o the few workstations on - 67 -the perimeter. The dynamic qua l i t i e s of daylight is an essential arch i tectura l element to give spaces i nd i v i dua l i t y and character. The current ly used uniform f lood l ight ing creates the opposite ef -fect:.: workstations cannot be i den t i f i ed since o f f i c e areas, c i r -culation., and service spaces are equally l i t . Furthermore, the control system of an open plan o f f i c e i s mostly designed in a way ..V that the environment cannot be control led i nd i v idua l l y . In respect to a r t i f i c i a l l i g h t i n g , open planning produces often l i gh t switching systems that are cent ra l l y control led and work for whole f l oo r areas rather than for individual workstations. Only recently these disad-vantages have been rea l i zed . The non-uniform l i gh t i ng approach with indiv idual task l i gh t ing in open plan is now becoming more important. 3.2.2.3. Energy Implications The energy impl ications of the open plan o f f i ces derive from the fact that deep o f f i c e space i s required to accommodate th i s type of lay-out, and that the lay-out f l e x i b i l i t y requires a uniform qua l i ty of the internal environment throughout the bu i ld ing. A r t i f i c i a l l i g h t i n i s used permanently. This increases both the energy consumption for d i rec t l i g h t and the energy required to o f f set the heating effects of l i g h t s . Open plan also requires mechanical vent i l a t ion and a i r -condit ioning, since natural vent i l a t ion i s generally not possible in s u f f i c i en t amounts. The amount of energy used for vent i l a t ion and a i r -conditioning i s substant ia l , as i t was demonstrated in Figure 3.1. above Current speculative o f f i c e development practice demands that e i ther c e l l u l a r or open plan o f f i ce s can be accommodated in the bui ld ing s h e l l . The options must be kept open. This precludes design solutions - 68 -that are c lose ly designed to the indiv idual needs of the user. The energy implications of. th i s approach are considerable. The extent to which innovative energy e f f i c i e n t practices can be introduced i s l im i ted . The neutral frame, which i s offered by the "general o f f i c e area" , requires a higher degree- of ( i n s ta l l a t i on and a design of the mechanical and e l e c t r i c a l system that provides equally good environ-mental conditions over the whole f l oo r area. The result, i s an increased energy consumption of these technical systems and a p a r t i a l l y "over-i n s t a l l a t i o n " of bui lding technology. 3.3. New Lay-Out Concepts The l a s t two decades of o f f i ce bui lding design were d e f i n i t e l y characterized by the trend toward the o f f i ce as a f l e x i b l e and a l terable container with l i t t l e d i f f e ren t i a t i on of space by l i g h t i n g , temperature or arch i tectura l features of the bui lding s h e l l . " . . .a rch i tecture , insofar as i t concerns working space and apart from r ea l l y exceptional cases, has been so stripped through processes of reduction, s imp l i f i ca t i on and modif icat ion, so cut down to the lone and mor t i f i ed , as to become the shel l of nothing but a container of functions, machines and persons, equipped with sophisticated technology to sa t i s f y the needs of employers and the physical require-ments of equipment and i n s t a l l a t i o n s . The psychological and inner requirements of the i nd i v i dua l ^ in these cases, have simply been ignored."29 As a reaction to th i s trend very recently a;;new idea was introduced in the lay-out planning of o f f i c e bui ld ings. It i s more concerned with the bui lding block as a whole than with the typology of the o f f i ce space. The new concept of work environment i s based on the be l i e f that o f f i ce work i s not an a c t i v i t y that can be separated from other da i l y a c t i v i t i e s . As a consequence co l l a t e r a l functions and services - 69 -are introduced in o f f i c e planning to create more d i s t i n c t and decis ive l inks between work, connecting and recreation zones. Spa t i a l l y th i s i s expressed by courts or a t r i a , that provide public areas and open space inside a bu i ld ing. These central spaces, overlooked by the work areas, estab l i sh a pattern of internal communication and c i r cu l a t i on that i s characterized by variety and d i f f e r e n t i a t i o n . Communication areas and service areas are mixed with working areas. In fact functional d i s t i nc t i on s between "productive" a c t i v i t i e s and services do not occur. The communication areas in the o f f i c e also serve to separate the groups and areas for breaks, which are f i t t e d into the working environment. This has changed the whole idea of the conventional o f f i c e and the views of the human and social re lat ionsh ips that developed within i t . 3 0 Figure 3.14 shows an example of th i s most recent trend. Figure 3.14. Central Beheer Insurance Company Of f i ce Bu i ld ing, Appel-dorn. Holland. Architect H. Hertzberqer - 70 -The c o n c e p t o f s p a t i a l l y d i f f e r e n t i a t e d zones i n o f f i c e b u i l d i n g s o f f e r s a wide p o t e n t i a l f o r t h e e f f i c i e n t use o f energy. The main advantages o f such b u i l d i n g t y p e s i s t h a t the d a y l i g h t p o t e n t i a l i s i n c r e a s e d by t h e extended " p e r i m e t e r " and t h a t a b u f f e r zone i s c r e a t e d which can be used f o r n a t u r a l h e a t i n g and v e n t i l a t i o n o r t o moderate the impact o f the e x t e r n a l e n v i r o n m e n t a l f a c t o r s . 31 F i g u r e 3.15. A t r i u m Type O f f i c e B u i l d i n g 4. THE WORKSTATION The development of the workstation in o f f i ces was characterized by the fast growing mechanization and automation of the o f f i ce , work, supported by more sophisticated machines and processors. However the trend toward more rat ional and e f f i c i e n t work processes changed the o f f i c e environment. Psychological ly the o f f i ce became characterized by stress due to the increased pace. Phys ica l ly the e f f i c i ency measures profoundly affected the design of the o f f i c e fu rn i tu re . At f i r s t the p r o l i f i c a t i o n of the technical equipment was chaotic insofar as each item was designed to resolve a par t i cu la r need, regardless of the other pieces. However,soon the need arose to combine the d i f fe rent items and to intergrate i t in the design of the workplace. This gave b i r th to the modern workstation. The trend in lay-out planning toward deep open space places greater emphasis on the workstation. Furniture, beside resolving the workstations organizational problem, now also has to deal with matters that were previously more typ ica l of architecture in bui ldings. • Workstations provide spat ia l d i f f e ren t i a t i on with screens, shelves and the l i k e . They provide elements to accommodate e l e c t r i c and telephone wires and incorporate systems of task and ambient l i gh t ing which, by rendering the conventional uniform c e i l i n g l i gh t i ng super-', f luous, create more a r t i cu la te and l i v e l i e r conditions of i l luminat ion as wel:l as decrease the i n s t a l l ed Wattage per unit f l oo r area "with i t s attendant energy savings. F i n a l l y , some workstations do also d i s t r i bu te a i r -condit ion ing to the workstation.32 - 72 -- 73 -5. NOTES 1. James M. F i t ch , "Pr imit ive Architecture and Cl imate," S c i e n t i f i c American 203 (December 1960). 2. Interview with Terry C a t e l l . Musson,.Catell A rch i tect s , Vancouver, B.C., \18 .December 19.79. 2. b. Province of B r i t i s h Columbia, Min istry of Energy, Mines and Petroleum Resources, "Energy Management for Commercial Bui ld ings, " paper presented at the Conference "Energy Ef f i c iency and the Bottom L ine, " Vancouver, 25 October 1979 (Preliminary copy), p. 17. 3. Fred S. Dubin and Chalmers G. Long, Energy Conservation Standards (New York: McGraw-Hill, 1978), pp. 3-5. 4. Ib id. 5. Regina B. Armstrong, The Off ice Industry: Patterns of Growth and Location (Cambridge, Mass.: MIT-Press, 1972), p. 14. 6. Frank Duffy, C. Cove and John Worthington, eds., Planning Off ice Space (London: Architectura l Press, 1976), p. 231. 7. Ernest F. Schumacher, Small i s Beautiful (New York: Harper and Row, 1973), p. 63 and p. 155. 8. Jean Gottmann., " ," Geographical Review 51 (May 1966), p. 191. 9. Mi l f red F. Schmertz, Off ice Building Design (New York: McGraw-H i l l , 1975), p. 180. 10. Ibid. 11. Richard G. S te in , Architecture and Energy (New York: Anchor/ Doubleday, 1978), p. 68. 12. Wi l ly Boesiger, ed. , Le Corbusier: Oeuvee Complete (Zurich: Girsberger, 1957), p. 104. 13. P h i l l i p Steadman, Energy, Environment and Building (New York: Cambridge University Press, 1975). 14. Kevin Summers, "Analyzing the Gropius House as Energy-Conscious Design," AIA-Journal, February 1977, pp. 28-35. 15. John Hix, "Energy Conservation and the Arch i tect : Part I," The Canadian Arch i tect , February 1977, pp. 18-38. - 74 -16. / - ., Handbook of Fundamentals (London: Architects Journal, 1971). 17. Richard 6. Ste in, "Energy Required for Bui lding Construction," in Energy Conservation Through Building Design, ed. Donald Watson (New York: McGraw-Hill, 1979), p. 191. 18. Ernest Wotton, "Some Considerations Af fect ing the Inclusion of Windows in Off ice Facades," Lighting Design and  App! icat ion, February 1976, p. 33. 19. M. Scott, American Town Planning Since 1890 (Berkeley: University Press, 1969). ~ 20. F.J. Langdon, Modern Off ices: A User Survey, National Buildings Studies, Research paper 41 (London: Her Majesty's Stationary Of f i ce , 1966), p. 12. 21. Province of B.C., op. c i t . , p. 20. 22. Maximilian G. Meyer, "Values in Arch i tecture" (Master Architectura l Thesis, University of B r i t i s h Columbia, 1979), p. 138. 23. Frank Duffy et a l t e r i , op. c i t . , p. 72. 23b.Jurgen Joedicke, Off ice Buildings (New York: Praeger,. 1962) p. 19. 24. Frank Duffy et a l t e r i , . op. c i t . , p. 72. 25. Christopher Alexander et a l t e r i , A Pattern Language (New York: Oxford Univers ity Press, 1976), p. 691. 26. John P i l e , Open Off ice Planning (London: Whitney/The Architectura l Press, 1978), p. 23. 27. Ib id . , p. 98. 28. Arno Lappat, Cr i t ique of the Officescape, transla.ted,\Baiien - " . und Wohnen 25 (1): 1-3, 1971 (Ottawa: NRCL Technical Trans lat ion, 1972), p. 5. 29. Bruno Scag l io la , "Manuale Sull 'Ambiente di layora, " DOMUS, special issue, December 1979, p. 4. 30. I b id . , p. 31. Photograph of Off ice Bui lding of John Deere and Company in Molina, U.S. Arch i tects : K. Roche, J . Dinkelbo' and Associates. - 75 -32. F r i t z Reuter, "Entwicklungstendenzen der Gebaudetechnik im Bureauhausbau," BauweVt 67 (#14, 1976), p. 447. 33. Bruno Scag l io la , op. c i t . , p. 6. - 76 -PART TWO: ENERGY CONSERVATION STRATEGIES - 77 -CHAPTER IV: ENERGY MANAGEMENT STRATEGIES 1 . INTRODUCTION 2. PERSONAL FACTORS 2 . 1 . Temperature Range 2.2. A c t i v i t y and Clothing 2.3. Vent i lat ion Rate: smoking/non-smoking 2.4. Lighting Levels 3. OPERATIONAL CHARACTERISTICS 3 .1 . Hours of Operation 3.2. Operation with Respect to A c t i v i t i e s 4. MECHANICAL AND ELECTRICAL SYSTEM DESIGN 4 . 1 . The Mechanical System 4 . 1 . 1 . System Capacity 4.1.2. System Selection 4.1.3. System Maintenance 4.1.4. D i s t r ibut ion of Energy Around Building 4 .1.5. Heat Recovery Systems 4.2. The Lighting System 4.2.1. System Design and Selection 4.2.2. System Maintenance 4.2.3. Heat-of-Light System 5. CONTROL SYSTEMS DESIGN 6. NOTES - 78 -CHAPTER IV: ENERGY MANAGEMENT STRATEGIES 1. INTRODUCTION In any business there are basic techniques which must be applied to a c t i v i t e s such as administrat ion, f inance, or" production in order to make the enterprise successful. Energy management i s the appl icat ion of those techniques to the use of energy resources. Making the most e f fect i ve use of energy through e f f i c i e n t appl icat ion and reduction of waste w i l l keep energy consumption and costs at a control led minimum. In order to conserve energy in the ent i re bui ld ing sector, energy conservation strategies must be applied to old and new bui ld ings. Energy management deals predominantly with ex i s t ing structures. Management strategies are important because ex i s t ing buildings w i l l represent a major portion of a l l buildings in use for many years to come. However, some of these strategies may also be useful ly applied in new buildingJdesign. Energy management decisions must be based on an evaluation of the actual energy use in a bui ld ing. The breakdown of o f f i ce energy use gives indicat ions where and how much energy i s used. The energy consumption pattern in commercial buildings i s quite var iab le. Even within the same locat ion, the var iat ion in energy use per unit area can be considerable. For example, despite the fact that a l l o f f i ce buildings sa t i s f y e s sent ia l l y the same require-ments, some o f f i ce s in Vancouver use s ix times more energy per unit - 79 -area than others. The range presented by B.C. Hydro i s 195 to 1240 KWh/m /year with a mean value at 550 KWh/m'Vyear. In sat i s fy ing user needs, energy i s required to: i ) provide heating and vent i l a t ing i i ) provide cooling i i i ) provide l i gh t i ng iv) supply power for equipment v) move energy around the bui lding (fans, pumps) v i ) supply domestic hot water Figure 4.1.: Breakdown.of Off ice Energy Use 3 - 80 -Figure 4.1. shows the proportions which these end uses represent of overal l energy use in o f f i ce bui ldings. These f igures apply to the typ ica l o f f i ce in Vancouver, but care should be taken in general iz ing from th is f igure. The proportions w i l l vary from one bui lding to another. The var iat ion that would be encountered in practice results from factors in the fol lowing areas: i ) personal factors i i ) operational character i s t i c s i i i ) mechanical and e l e c t r i c a l systems design iv) control systems design v) bui lding design Table 4.1. i den t i f i e s these areas in re la t ion to heating/cooling, vent i l a t i on and l i g h t i n g , which together account fo r more than 85% of the tota l energy use (see also previous Figure 4.1.). The areas i dent i f i ed in Table 4.1. are used in the fol lowing sections to discuss some general energy management strategies. Management decisions in the personal and operational area have a substantial influence on the energy consumption of an o f f i ce bu i ld ing. Energy management studies suggest that the most and the easiest energy savings can be achieved by changes in operating procedures rather than by modified building or equipment des ign. 5 However, for the designer i t i s important to rea l i ze to which extent management decisions in the personal, operational and systems design areas influence his design decisions or vice versa. Tabl e 4.1.: Factors Influencing Energy Us PERSONAL OPERATION MECH. / ELECTR. CONTROL BUILDING DESIGN HEATING / COOLING . Temperature range . Clothing . Hours of opera-t ion . D i s t r ibut ion of a c t i v i t i e s . Density of oc-cupation . Preheating / night setback . E f f i c iency of mech. system . E f f i c iency of l i g h t -ing system . D i s t r ibut ion of energy around bu i ld . . Maintenance of systems . Thermostat con-t ro l . Who makes dec i -sions to adjust thermostat . Solar heat gain through windows . Fabric heat loss . I n f i l t r a t i o n loss . Perimeter / core r a t i o . Daylight potential . Degree of subdivis ion within bui ld ing VENTILATION . Vent i la t ion rate . Smoking / non-smoking . Hours of opera-t ion . Density of oc-cupation . Heat recovery system . Type / means of control . Volume of spaces . Natural ven t i l a t i on c apab i l i t i e s of b u i l -ding LIGHTING . L ighting levels . Hours of ope-rat ion . D i s t r ibut ion of a c t i v i t i e s . E f f i c iency of l i g h t -ing system . Type / degree of control . Who makes dec i -sion to control 1ights . Daylight c apab i l i t i e s of bui ld ing - 82 -2. PERSONAL FACTORS Personal factors are analysed under the fol lowing headings: i ) Temperature Range i i ) A c t i v i t y and Clothing i i i ) Vent i la t ion Rate iv) Lighting Levels 2 . 1 . Temperature Range The temperature at which a person feels comfortable depends on his c lo th ing, a c t i v i t y pattern, the humidity, the ve loc i ty of the a i r and the radiant temperature of the surrounding surfaces. Comfort conditions d i f f e r from person to person. For each indiv idual there exists an ambient temperature i n t e r v a l , within : which he feels reasonably comfortable. Due to these indiv idual d i f ferences, for a large group of persons with the same clothing and a c t i v i t y , there w i l l not ex i s t an interva l of temperature at which comfort w i l l be obtained for a l l persons at the same time. Optimum comfort zones' can only be described in terms of minimizing the number of persons who w i l l be d i s s a t i s f i e d . ^ The ef fect of a i r temperature on energy consumption is s i gn i f i can t . For Vancouver, there is an annual saving of about 5% for each degree the internal temperature is lowered during the daytime in winter. Annual savings of about 25% are achieved, i f the indoor temperature is also reduced by 5 C during the non-occupied periods of the Q bu i ld ing. S im i l a r l y , savings can resu l t when thermostat settings are increased in summer. These conservation measures increase the - 83 -temperature range or "dead band", such that thermal loads which cause internal temperature changes within the range, w i l l not cause a cont ro l l i ng response from either the heating or cooling system. A small increase in the temperature range can resu l t in a great leverage on heating and cooling loads.9 2.2. A c t i v i t y and Clothing The comfort diagram in Figure 4.2. shows the optimal temperature depending on man's a c t i v i t y and c loth ing. The a c t i v i t y i s measured by the unit "met!'' and the thermal resistance of the c lothing i s measured by the unit " c l o " (1 c<l'd, corresponds to a normal business s u i t ) . Figure 4.2.: Comfort Diagram^0 met 2.0 H 1.8 H > 1.6-r— > < 1.2-SEDENTARY 1<H SLEEPING 0.8 1 0 0.5 1.0 1.5 clo THERMAL RESISTANCE OF CLOTHING - 84 -A c t i v i t i e s in o f f ices f a l l under the general c l a s s i f i c a t i o n of sedentary. It i s hardly l i k e l y that increased physical a c t i v i t y in o f f i ces is a feas ib le way to reduce the energy used on heating. Clothing i s the most important factor inf luencing the thermal balance between the human body and the environment. Clothing can increase the range over which people are capable of adapting to the i r environment. However, the development in the standard of l i v i n g over the past decades and changes in fashion trends toward-1ighter and less c lothing have led to higher internal temperatures during the winter. The fact that less c lothing is now worn has the ef fect of greatly reducing the comfort zone.^ Figure 4.2. indicates that a change in c lothing habits provides a considerable potential for energy conservation. In addit ion to increasing c lo th ing , the chair can provide a substantial increment of the tota l clo-value for a sedentary person, such as an o f f i ce worker. It would be un rea l i s t i c to expect that people would change the i r c lothing habits d r a s t i c a l l y , since the insu lat ion value i s only one aspect of c loth ing. But even moderate changes could provide s i gn i f i cant energy savings. In th i s context the relaxation of ex i s t ing dressing codes and the suggestion of wearing thermal appropriate c lothing are important. - 85 -2.3. Vent i lat ion Rate: smoking/non-smoking Vent i lat ion rate i s the rate at which a i r in a room i s replaced in order to reduce or remove undesirable properties of the atmosphere in a room. The basic vent i l a t ion requirement for the human body is for adequate oxygen supply. An a i r exchange rate of 1.7 m3/h per person to the occupied area is enough to provide a s u f f i c i en t oxygen supply. The removal of odours i s more c r i t i c a l , because a 10 times larger amount (17.0 m /h person) i s needed for sat i s factory room c o n d i t i o n s J 2 However i t i s a d i f fe rent factor which proves most dominant. I t i s tobacco smoke. I f a smoking area i s to be vent i lated an a i r supply of at least 30 m3/h per person has to be provided to prevent unhealthy conditions. This doubling of the vent i l a t ion rate can cause s i gn i f i can t energy consumption. On the other hand, ref ra in ing from smoking allows to minimize the vent i l a t ion rate without any discomfort. 2.4. Lighting Levels A r t i f i c i a l l i gh t ing levels have been increased steadi ly over the past years. One of the main reasons for th i s trend was the resu l t of various studies conducted in the 5 0 ' s J 3 ' ^ » ^ 5 I t was pointed out that the e f f i c i ency in performing visual tasks i s in d i rect proportion to the lux level of d i f fuse l i g h t achieved in the space. As a consequence, in 1959 the I l luminating Engineering Society adopted l i gh t ing standards that were about 2 to 3 times higher that the previously accepted l i gh t i ng l eve l s . - 86 - -In the l a s t two decades th i s trend continued. 'More' came to be equated with ' b e t t e r ' , even though sometimes i t could be worse. Owners of o f f i ce space in competitive rental s i tuat ions met the i r competit o r ' s i l luminat ion l eve l s , and often put more i n . The recommendations of the IES-Handbook^ for d i f f i c u l t seeing tasks in o f f i ce s went progressively from 500 Lux in 1952 up to 2000 Lux in 1971. 1 7 I t i s now widely recognized that i t i s , above a l l , the qua l i ty of the l i gh t i ng and not pr imar i ly the quantity that provides a good visual environment. In uniformly l i t o f f i c e ;spaces a r t i f i c i a l l i gh t i ng levels can be reduced d r a s t i c a l l y by removing part of the l i gh t f i x tures without any loss in v isual comfort for the o f f i ce worker sJ^ However, careful thought should be given to the re lat ion of a c t i v i t i e s and l i gh t i ng leve l s . Generally, 1 ight should be supplied where i t i s actua l l y needed. Preferred l i gh t ing levels d i f f e r considerably according to spec i f i c task and effects of g lare, custom and indiv idual behaviour. It i s therefore useful to design an adaptable l i gh t i ng system that provides ambient l i gh t i ng with moderate l i gh t ing levels throughout the general o f f i ce area with l o c a l l y increased l i gh t i ng levels for spec i f i c tasks. Visual performance can also be improved by other means than increasing l i gh t ing l eve l s . Research by Sm i t h^ indicates that i t i s far more e f fec t i ve to make small changes in visual qua l i t i e s of the tasks, such as more leg ib le pr int ing and wr i t i ng , or increasing the pr int ing size than i t i s to increase i l l uminat ion . - 87 -3. OPERATIONAL CHARACTERISTICS 3 .1 . Hours of Operation The operational character i s t i c s of an o f f i ce bui lding determine the energy consumption more than any other f a c t o r . 2 ^ It i s the hours of operation of a system which play the important r o l e , since o f f i ce buildings are usually not used 24 hours a day. E f f i c i e n t operation means using energy only when i t i s needed. Even the most e f f i c i e n t system that operates, when not necessar i ly required, i s wasting energy. Straightforward savings methods are switching off l i gh t s and unused equipment. 2^ Appropriate scheduling for l i g h t i n g , heating and vent i l a t ion systems, combined with precise operational procedures for these systems can lead to substantial energy savings. This requires the implementation of special night and weekend schedules for temperature setbacks, c los ing air-dampers and shutting down ven t i l a t i on . Par t i cu la r attention must be paid to areas which have only part time occupancy, such as conference rooms, or areas which have an occupancy outside the general operation schedule. For example, i t has been estimated that those buildings which have a computer f a c i l i t y have a s i gn i f i cant increase in e l e c t r i c a l energy use. This results from the fact that, for economic reasons the computer f a c i l i t y operates on a 24 hour b a s i s . 2 2 Large areas of bui ld ing are generally serviced to support and sa t i s f y the operations. More precise zoning could e s sent ia l l y i so la te such spaces. S imi lar arguments apply to the amount of energy which must - 88 -be expended in support of evening cleaning s t a f f . 3.2. Operation with Respect to A c t i v i t i e s The a c t i v i t i e s in o f f i ce buildings are f a i r l y s imi la r in thermal terms and can be c l a s s i f i e d as sedentary. However personal factors , such as the degree of formal i ty , changing c lothing patterns, smoking habits and indiv idual preferances for l i gh t i ng levels can a l t e r the requirements for environmental control s i g n i f i c an t l y within a bu i ld ing. Furthermore, the density of workplaces assumes importance in defining prefered environmental condit ions. These changing requirements indicate that the uniform system operation throughout a bui ld ing i s inherently wasteful in energy, since the operation has to be conditioned to the areas in the bui lding where peak demands for l i g h t i n g , heating, cool ing or vent i l a t i on occur. Major energy savings resu l t i f the system operation i s related d i r e c t l y to the a c t i v i t i e s and occupancy. Again, th i s requires a careful bui ld ing and technical systems design based on the a c t i v i t y patterns. - 89 -4. MECHANICAL AND ELECTRICAL SYSTEM DESIGN 4.T. The Mechanical System Strategies for improving the e f f i c i ency of the mechanical system are proposed under the fol lowing headings: i ) System Capacity i i ) System Selection i i i ) System Maintenance iv) D i s t r ibut ion of Energy Around Bui lding v) Heat Recovery 4 . 1 . 1 . System Capacity Most energy use in buildings occurs when the outdoor temperatures are moderate. 2 3 Under such conditions the mechanical systems work at part load most of the time. Only a small amount of the tota l energy consumption i s used during temperature extremes. The system e f f i c i ency can be improved when the capacity of the mechanical system i s not necessari ly designed to meet the most extreme condit ions, but to meet conditions that occur more frequently. Great care should be given to how equipment performs when outdoor temperatures are moderate. 4 .1 .2 . System Selection A var iety of mechanical systems have been developed in recent years. Such systems, however, have been pr imar i ly designed to meet the required comfort standards, with l i t t l e concern for energy - 90 -e f f i c i ency . In many cases, simultaneously heating and cooling processes are necessary to achieve desired condit ions. Today much more e f f i c i e n t systems are ava i l ab le , which eliminate wasteful simultaneous heating and cooling through a var iable aiKvolume system combined with exhaust a i r heat recovery. 24 i n add i t ion, spec ia l l y designed mechanical systems can be selected to red i s t r ibute energy from parts of the bui ld ing where net heat gains ex i s t to other parts where heat i s required. In any case the select ion of an.'appropriate mechanical system has to be made by engineers in col laborat ion with a rch i tect s . 4.1.3. System Maintenance Since the serv ic ing of commercial buildings i s complex i t i s espec ia l l y important that a l l the mechanical equipment i s e f f e c t i v e l y maintained. Energy e f f i c i ency can be improved by optimizing pe r i od i ca l l y the working of mechanical parts and by replacing obsolete parts and f i t t i n g s . 2 5 4.1.4. D i s t r ibut ion of Energy Around Bui lding It takes energy to move energy for heating or cool ing. As i den t i f i ed in Figure 4.1. th is amount i s used by fans and pumps. It represents a s i gn i f i can t portion of the tota l energy consumption in an o f f i ce bu i ld ing. Again, i t i s the long hours of operation of the fans and pumps that determines th i s amount. Energy can be d i s t r ibuted more e f f i c i e n t l y when the fol lowing measures are taken: - reduce hours of fan and pump operation - improve performance of mechanical system - lower the resistance to flow in ductwork and pumping system - use low pressure systems The l a t t e r two proposals imply an increase of the cross-section of the ducts. This requires an increase of the c e i l i n g plenum to accommodate .the ductwork and an integrat ion in the design of the 07 structural system. 4 .1 .5 . Heat Recovery Systems Off ice buildings generate considerable amounts of heat. Often the excess heat i s removed to the outdoor, while cold,, fresh a i r i s introduced into the bu i ld ing. Heat recovery from the exhaust a i r can greatly improve the energy e f f i c i ency with which the bui lding can be operated. However-, the arch i tect has to recognize that the appl icat ion of heat recovery i s l imi ted to mechanical systems. Natural vent i l a t i on precludes heat exhange recovery systems. There are a var iety of systems for recovering and red i rect ing otherwise wasted heat. The heat pump, the heat recovery wheel and the heat pipe are just three examples, and further reference should be made to spec i f i c sources. 2 ^ ' 29, 30 - 92 -4.2. The Lighting System Strategies to improve the energy e f f i c i ency of the l i gh t i ng system are proposed under the fol lowing headings: i ) System-Design and Selection i i ) System Maintenance i i i ) Heat-of-Light System 4.2 .1 . System Design and Selection The select ion of an appropriate and e f f i c i e n t l i gh t i ng system depends largely on design decisions made e a r l i e r in the design process of the a rch i tect . I t i s important that the l i gh t i ng system matches and supports the basic design strategy. If, for instance, largely dayl ight i s provided, the a r t i f i c i a l l i gh t i ng system must be designed in a way that i t ass i s ts th i s basic goal of natural i l l uminat ion . Perimeter l i gh t ing that can be switched of f becomes c r u c i a l . Lighting systems are more e f f i c i e n t i f they are related to the ac t i v i t i e s• they support.^ In th i s context the non-uniform l i gh t i ng approach, where tasks are i l luminated according to the actual needs, must be stressed again. 4.2.2. System Maintenance The maintenance of the l i gh t i ng equipment is most essential „to ensure adequate i l l uminat ion . Periodic inspection programs should be established to check the cleanl iness of the l i g h t f i x tures as - 93 -well as the proper adjustment of the';1 ight to the workplaces, i f tasks have been relocated. L i fe -cyc le cost benefit analyses indicate that i t i s e f fect i ve to relamp o f f i ce space by a group replacement plan at 80% of the rated hours of f luorescent lamps. 3 2 4.2.3. Heat-of-Light'System A substantial part of the energy used by l i gh t i ng i s discharged into the o f f i c e space in the form of heat. Throughout most of the year th i s internal heat gain is undesired and has to be removed, which consumes addit ional energy. In a heat-of-Tight sytem the unwanted heat gain of l i gh t s can be reduced by forc ing the return a i r of the a i r -cond i t ion ing system through the l i gh t i ng f i x t u re s , thus cooling the lamps and reducing the bui ld ing a i r -33 conditioning load. Heat-of-1ight systems were widespread in new o f f i ce buildings in the l a s t two decades. But with the trend to se lect ive task l i gh t ing and reduced general l i gh t i ng l e ve l s , these sytems now are questionable. The p r inc ip le advantage with heat-of -1 ight systems now i s the potential they of fer to c o l l e c t excess heat/ in the i n t e r i o r areas of large buildings and to transmit i t to the colder areas on the perimeter. Heat-of-1ight systems can e f f ec t i ve l y be combined with heat recovery and storage sytems. - 94 -5. CONTROL SYSTEMS DESIGN Control systems are means to regulate the supply of heating/ cool ing, vent i l a t ion and l i gh t i ng . Control systems are e i ther manual type or automatic. . In selecting: the type of control system the i nd i v i dua l ' s need and circumstances have to be considered. Large o f f i ce buildings with complex serv ic ing require generally f u l l y automatic controls,, whereas smaller buildings can be part ly manually controlled'. Considerations should be given to the po s s i b i l i t y of combining automatic and manual controls. This would be feas ib le in case of natural vent i l a t ion and for the l i gh t ing system. In th i s context the management of the control systems i s important. Automatic .controls?, have to be adjusted and checked regular ly to insure proper functioning. If manual controls are provided, re spons ib i l i t y for control has to be delegated. This assures that controls are e f f i c i e n t l y used. The degree and density of automatic controls i s an essential element in energy conservation. I t determines the a b i l i t y to control indiv idual spaces according to the i r spec i f i c needs. Studies indicate that room-by-room thermostatic control for.heating w i l l save a considerable percentage of the energy that a s ingle thermostatic control uses.34 in open plan o f f i ces i t i s necessary to d ist inguish d i f fe rent zones that are separately contro l led. In the areas close to the windows the d i f fe rent requirements of the d i f fe rent or ientations must be recognized. With respect to l i g h t i n g , substantial savings can be achieved by increased switching - 95 -and dimming. Light dimming i s a technique that controls the e lec t r i ca l , input in a manner to provide stepless attenuation or from bright to dark. Dimming i s espec ia l ly e f f i c i e n t in combination with dayl ight ing. The natural var iat ions in the a v a i l a b i l i t y of daylight can be supplemented by the dimming or switching of the a r t i f i c i a l l i gh t i ng system. 96 -NOTES 1. B.C. Hydro, Energy Services D iv i s ion: "Energy Management for Business," eff ic ient-use-of-energy data, No. EC 401, Vancouver, B.C., 1977, p. 1. 2. R.T. Martin, "Energy E f f i c i en t Heating and A i r Conditioning Systems", paper presented at the Conference "Energy Ef f ic iency and the Bottom L ine " , Vancouver, B.C., 25 October 1979. 3. Province of B r i t i s h Columbia, Ministry of Energy, Mines and Petroleum Resources, "Energy Management for Commercial Bu i ld ings " , paper presented at the Conference "Energy E f f i c iency and the Bottom L ine " , Vancouver, B.C., 25 October, 1979 (preliminary copy) p. 17. 4. Ray J . Cole and F.S. McKay, "Energy Management in Commercial Bu i ld ings " , paper presented at the Conference, "Energy E f f i c iency and the Bottom L ine " , Vancouver B.C., 25 October, 1979. 5. Richard Sa l te r , R. Petrusche l l , K. Wolf,/Energy Conservation in Non-Residential Bui ld ings ' , Rand Corporation Report R-1623-NSF (Santa Monica, Ca.: Rand Corporation, 1976) , p. v i . 6. .P.O. Fahger, "Human Comfort and Energy Consumption in Residential Bu i ld ings " , i n : Energy Use Management, proceedings of the International Conference in Tucson, Arizona, October 24-28, 1977, vo l . 1 (New York: Pengamon, 1977) , p. 428. 7. Ray Jv:'Co.le, "Energy Conscious Design F i l e " , AIBC Forum, May 1979, " p . 12. 8. Ray J . Cole, op. c i t . , p. 12 9. Richard Salter et a l t e r i , op. c i t . , p. 12 10.. P.O. Fanger, Thermal Comfort (New York: McGraw-Hill, 1973) 11. Ray J . Cole, op. c i t . , p. 12 12. Canada National Research Counci l , Measures for Energy Conservation  in New Buildings 1978, NRCC report no. 16574 (Ottawa: NRCC, 1978), p. - 97 -13. Terry Ca r g i l , "Light and Colour Engineering in Post O f f i ce s , " I l lumination Engineering .(October 1954), p. 477. 14. Public Buildings Administrat ion, The Influence of L ight ing, Eyesight, and'Environment upon Work Production (Washington, D.C: U.S. Government Pr int ing O f f i ce , 1947). 15. H.R. B lackwel l , "Report to the IES", Vision Research Laboratories, University of Michigan, 1958. 16. I l luminating Engineering Society, IES-Handbook 1972, IES New York (Baltimore, Mg.: Waverly Press, 1972). 17. In th i s context i t i s interest ing to observe that i l luminat ion standards in d i f ferent countries for spec i f i c types of visual tasks vary considerably. The levels are highest in the U.S., followed by Holland and Switzerland, whereas standards in England are much lower. This indicates that recommended l i gh t i ng levels are set not so much on the basis of the actual l i gh t ing requirements, but on economic condit ions, including the re l a t i ve price of e l e c t r i c i t y . 18. Reduction of l i gh t i ng level may c o n f l i c t with ex i s t ing codes. Lighting levels in o f f i ces in B r i t i s h Columbia are regulated by the Factory Act of 1970. The required minimum standard for normal o f f i ce seeing task i s 70 Lux. However, e f f i c i e n t and careful l i gh t ing design can provide an excel lent visual environment with no more .than 50 Lux. This discrepancy shows thatnthere is a need to revise l i gh t ing standards that have been established in "pre-conservation" days. 19. St. W. Smith, "Performance of Representative Off ice Task as a Function of I l lumination Leve l , " report to the r. Federal Energy Administrat ion, Washington, D.C.,' ( 1 ' " Ohio State Univers i ty, 1975. 20. Lawrence G. Spielvogel, "How and Why Buildings Use Energy," in Energy Conservation Through Bui lding Design, ed. D. Watson (New York: McGraw-Hill, 1979), p. 53. 21. V ictor D. Chase, "Lighting and Energy E f f i c i ency , " Lighting Design and Appl icat ion (September 1977), p. 14 22. Enviro-Management and Research Inc., "Energy Consumption in Commercial Buildings in Ph i lade lph ia , " National E l ec t r i c a l Manufacturers Associat ion, New York 1975. - 98 -23. Lawrence G. Spielvogel, "Exploding Some Myths about Bui lding Energy Use," Architectural Record, February 1976, p. 125. 24. Province of B r i t i s h Columbia, op. c i t . , p. 24,. 25. Thomas Imperatore, "Proven Ways to Save Energy in Commercial Bui ld ings, " Heating/Pi ping/Air Conditioning (May 1975), p. 49. 26. Fred S. Dubin and Chalmers G. Long, Energy Conservation Standards (New York: McGraw-Hill, 1978), p. 259. 27. T.A. Markus and E.N. Morris, Bui ld ings, Climate and Energy (London: Pitman, 1980), p. 476. 28. Gerald Foley, "Energy Saving at HEVAC," Architectura l Design, June 1976, p. 372. 29. Fred S. Dubin and Chalmers G. Long, op. c i t . , p. 371. 30. Kurt Brandle et a l t e r i , Energiebew usster Bauen (Stuttgart: Koch, 1979), p. 54. 31. - .i "EMS-5: Energy Management and the Lighting of Off ice Bu i ld ings, " Lighting Design and App l icat ion, February 1977, p. 18. 32. Fred S. Dubin and Chalmers G. Long, op. c i t . , p. 215. 33. Harry B. Zackrison, " I n t e r i o r l i g h t i n g and Energy Consciousness," Lighting Design and App l icat ion, Ap r i l 1978, p. 33. 34. W.S. Harris and C H . F i t ch , "Performance of a Seven Zone Residential Hydronic Heating System," ASHRAE  Transactions (Part 1, 1967). 35. Donald K. Ross, "Notes on E l e c t r i c Lighting Controls, " Energy and Buildings (Lansanne: E l sev ier , 1977), p. 103. - 99 -CHAPTER V: OFFICE BUILDING,DESIGN STRATEGIES 1. INTRODUCTION 2. PLANNING LEVEL: SITE 3. PLANNING LEVEL: LAY-OUT 4. PLANNING LEVEL: FORM 5. PLANNING LEVEL: FABRIC 6. NOTES - 100 -CHAPTER V: OFFICE BUILDING DESIGN STRATEGIES 1. INTRODUCTION Design decisions by architects determine to a large degree the energy consumption pattern of o f f i c e bui ldings. This chapter deals, s p e c i f i c a l l y from a designer 's point of view,with conservation strategies that improve the energy e f f i c iency of o f f i c e bui lding design. The general objective of strategies for .energy e f f i c i e n t o f f i ce design is to improve bui lding design in a way that desired indoor space conditions are provided and maintained with a minimum amount of energy. In bui ld ing design there are "ac t i ve " and "passive measures" to solve arch i tectura l problems with respect to energy e f f i c i e n c y J Whereas "act ive measures" involve predominantly mechanical equipment, the "passive" approach uses mainly the bui lding i t s e l f ( i t s o r ientat ion, form, lay-out and envelope character i s t i c s ) to modify the prevai l ing weather to the desired space cl imate. "Passive measures" are pa r t i cu l a r l y e f f ec t i ve , since no addit ional energy is required for operation. Most of the "passive measures" in energy conservation can be achieved using current bui lding construction practices; s.ome with an addit ional i n i t i a l capita l investment, some with no added cost, and some even with a reduction. Of course, "act ive measures" can also be u t i l i z e d bene f i c i a l l y at times, as long as they are thoughtfully integrated in the bu i ld ing ' s design. Energy e f f i c iency is not something that is imposed on a bui ld ing and achieved so le ly by mechanical means. Since the bui lding and i t s - 101 -mechanical system are i n teg ra l , the professions should work c lose ly together from the inception of the design. Five basic strategies can be i dent i f i ed for energy e f f i c i e n t o f f i c e design: i ) Control internal heat gains, i i ) Control solar heat gains, i i i ) Minimize heat losses, iv) Optimize natural vent i l a t ion c apab i l i t i e s , v) Maximize dayl ight capab i l i t i e s of bui ld ing. These strategies are further examined in the fol lowing sections under the 4 planning levels of s i t e , lay-out, form and f ab r i c . i ) Planning level 1 deals with the s i t e . The re lat ionsh ip of the bui ld ing to the ex i s t ing c l imat ic conditions and the influence of adjacent buildings is considered, i i ) Level 2 considers the strategies dealing with lay-out design and the spat ia l organization in respect to energy use. i i i ) Level 3 deals with bui lding form. The shape, s ize and or ientat ion of a bui lding can be used to achieve improved energy e f f i c i ency , iv) Level 4 comprises bui lding f ab r i c . The bui lding skin (walls and windows), the bui lding materials and the i r properties and deta i l i ng are important elements to make a bui lding energy e f f i c i e n t . However, the fol lowing points should be considered: i ) Strategies for energy e f f i c i e n t design can be applied at a l l l eve l s . Design decisions at a higher level help to lessen the impact of the environmental factors which must be dealt with - 102 -at a lower planning l e v e l . i i ) The strategies have to be chosen according to the spec i f i c circumstances. For instance, the strategy of cont ro l l i ng internal heat gain does not apply at the level of s i t e , i i i ) The strategies are in ter re la ted. This in ter re la t ionsh ip is dealt with at the d i f fe rent planning leve l s . iv) Although they share the common goal of energy e f f i c iency the basic strategies may appear contradictory. Each bui ld ing has to be analysed ind i v idua l l y to assess which strategy( ies) i s most appropriate. • . : ' ' : * v) The strategies deal with energy e f f i c iency in o f f i c e bui ldings. However, the issues of energy e f f i c iency have to be related to the socia l and organizational needs of the bui lding users. The design of an energy e f f i c i e n t bui lding cannot be described adequately in terms of a simple check l i s t . Each bui lding has i t s own set of c r i t e r i a and relat ionships between these have to be considered. It i s the a r ch i t ec t ' s r e spons ib i l i t y to resolve each problem according to i t s par t i cu la r context. It i s therefore impossible to describe exactly a s ingle idea approach for energy conservation for any bui ld ing. However, i t i s useful to introduce in a general way strategies which promote energy e f f i c i ency , demonstrate how they could be implemented and leave the arch i tect to interpret the general pr inc ip les and the technical solutions to spec i f i c problems. Good design has always taken energy e f f i c iency into consideration. - 103 -There are numerous examples in the t rad i t i ona l and vernacular architecture. A good design incorporates energy e f f i c iency without demonstrating an overemphasis towards energy features, but i t can be recognized d i s t i n c t l y among other bui ldings. A poor or unsatisfactory design in arch i tectura l terms w i l l usually resu l t when energy conservation strategies are applied mechanically to a standard bui lding without reconsidering i t s fundamental concept. - 104 -2. PLANNING LEVEL: SITE 2.1 Objective 2.2. Analyze S i te Climate 2.3. Design in a Climate - Responsive Manner 2.4. Provide Solar Access 2.5. Maximize Daylight Potential 2.6. Optimize Potential for Natural Vent i la t ion - 105 -2. PLANNING LEVEL: SITE 2.1. Objective This section i den t i f i e s energy conservation strategies at the s i t e planning level which help to lessen the adverse effects of the climate upon the bui lding and which maximize the benef ic ia l ef fects of the cl imate. The effectiveness of modifying, select ing or excluding the external climate determines to a large extent the amount of non-renewable energy required to operate a bui lding at desired 3 indoor conditions. The analysis and understanding of the s i t e climate becomes therefore the i n i t i a l strategy for energy conservation. 2.2. Analyze S ite Climate The goal of an analysis of the s i t e climate is to get a broad understanding of the dynamic influences of the c l imat i c elements on a s i t e in order to develop design strategies. The main climate elements a f fect ing the energy demand of buildings are: i ) solar radiat ion i i ) a i r temperature i i i ) wi nd iv) atmospheric radiat ion v) p rec ip i ta t ion These c l imat i c elements are further described in Appendix A. Information about the c l imat i c elements can be obtained by two methods: published data and d i rect measurement. - 106 -Published meteorological data, co l lected from the nearest a i rport or retr ieved from standard design manuals, such as the ASHRAE Handbook of Fundamentals 4, allow the arch i tect to get quickly an overview of the climate in the area of a spec i f i c s i t e . However, these standard, data are generally not applicable d i r e c t l y to the bui lding design, since the meteorological conditions may vary considerably from the place where the data were co l lected to the 5 actual bui ld ing s i t e . The deviations become more pronounced over a topographically structured and densely b u i l t area than over an area that i s f l a t . In such s i tuat ions i t becomes imperative to gather information about the s i t e climate by d i rect measurement. For large scale projects i t can be worthwhile to c o l l e c t spec i f i c information about the microclimate by a temporary meteorological s tat ion on a s i t e . How-ever, time and cost factors make th i s an impractical so lut ion. In such cases d i rec t measurements must be co l lected by spot v i s i t s to the s i t e . Having a general understanding of the regional c l imate, the arch i tect can observe with or even without simple tools local differences of wind and temperature on a given s i t e . For most pract ica l purposes th i s method is s u f f i c i en t to ident i f y sheltered and exposed areas on a s i t e in an early planning stage. In any case analyzing s i t e climate should involve a v i s i t to the proposed s i t e . This gives the arch i tect the opportunity to experience the interplay of the c l imat ic elements, which may not be noticeable from the raw c l imat ic data. Also, observations of the surroundings give important clues to the microclimate of a s i t e . Often the surrounding buildings or landscape can influence the microclimate to a degree that i s not predictable from the co l lected data. - 107 -2.3. Design Climate Responsive Having obtained a broad understanding of the spat ia l and temporal var iat ion in climate over a s i t e , the arch i tect can then assess whether the climate is imposing a constraint or benefit on bui lding design. If a climate i s favourable, then the concern should be to prevent the bui lding from modifying i t in an unfavourable manner. If i t i s unfavourable, then the object ive should be to minimize its. impact and, to improve the mi,cro-cl imatic conditions Using the co l lected c l imat ic data and the observations on the s i t e i t i s possible to c l a s s i f y sheltered or exposed s i tes or parts thereof. In sheltered areas the arch i tect should take factors into account that might aggravate microcl imatic condit ions, such as wind funnel l ing and shadow cast of bui ldings. Exposed areas, where adverse c l imat i c conditions p r e va i l , should be avoided. If economic considerations do not allow t h i s , the adverse effects of climate must be compensated for by measures in landscaping, bui lding form and f ab r i c . In th i s context i t i s important to rea l i ze the influence the arch i tect has on decisions in s i t e planning, as outl ined by R. Cole.^ The designer seldom has a choice of s i tes and is not generally involved in the comparison of the advantages and disadvantages of vast ly d i s s im i l a r s i t e s . This i s pa r t i cu l a r l y the case in a developed area in which the proposed bui lding w i l l have to comply with ex i s t ing access points, zoning ordinances and urban gr id patterns. However, in certa in instances the locat ion of the bui lding and the s i t e r e l a t i ve to ex i s t ing topographical features, vegetation or ex i s t ing buildings can prove s i gn i f i cant in terms of the enhancing of the microclimate created by the inc lus ion of the proposed bu i ld ing . . - 108 -In order to design in a climate-responsive manner, i t i s not only necessary to consider the re la t ion between s i t e and c l imate, but also the re la t ion between the a c t i v i t i e s in buildings and the cl imate. The designer can compare an a c t i v i t y analysis to the record of microcl imatic condit ions, and from the comparison determine which conditions are most desirable and when these conditions regular ly occur. Off ices are characterized by a general operation time from 8 a.m. to 6 p.m. Since th i s operation time pa ra l l e l s the time of highest solar rad ia t ion , strategies can be developed to maximize i t s benefit by increasing dayl ighting or by using solar energy for heating purposes in winter. On the other hand, in summer the high solar radiat ion during the main occupation time c a l l s for e f fec t i ve measures to minimize solar gains, or even to use solar energy for cooling processes.^' ^ 2.4. Provide Solar Access Solar radiat ion has always been valued for the pos i t ive ef fect on the spaces around bui ldings. For centuries laws, mindful of health benef its , insured access to s u n l i g h t . ^ Today, designers of o f f i c e buildings are also aware of the importance of. solar energy as a replacement for non-renewable energy. Because of the r i s i ng o i l and gas pr ices, solar heating/cooling and the preparation of domestic hot water with solar energy has become increasingly economical within the l a s t seven y e a r s . ^ Simultaneously the importance of providing access to the sun has grown. Solar access how has an eth ica l aspect. Designing an. - 109 -o f f i c e tower that achieves energy e f f i c iency through the use of solar power, but deprives the neighbouring buildings access to ' the sun, re f l ec t s questionable eth ics . Providing solar access is therefore an essential design strategy when studying the s i t e . This strategy requires the designer to consider the mutual influence of the surrounding buildings and the proposed bui ld ing. The " so la r envelope" i s a conceptual tool to describe the volumetric l im i t s to a development that w i l l not shadow i t s ; 12 13 neighbour. ' - 110 -The s ize and shape of the envelope varies depending on deviation of solar access, s i t e , and surrounding bui ldings. Figure 5.2. i l l u s t r a t e s the ve r t i ca l property l ines generated by the requirement that solar r ights of ex i s t ing buildings be respected. 15 Figure 5.2.: Solar Envelope and Adjacent Buildings The implementation of the " so lar envelope" concept adds a new dimension to the ex ist ing zoning laws that were developed without energy e f f i c iency in mind. However, i t must be emphasized that the implementation of the " so lar envelope" depends largely on the readiness of the property owners to recognize solar access as a fundamental value. The adoption of the " so la r envelope" concept w i l l e f fec t the development of the c i t i e s s i g n i f i c an t l y . Streets w i l l not look - I l l -a l i k e , s i n c e development w i l l t e n d to be lower on t h e s o u t h s i d e o f a s t r e e t t h a n on t h e n o r t h i n o r d e r t o r e d u c e shadow c a s t . The b u i l d i n g h e i g h t w i l l be m i n i m i z e d . High r i s e development w i l l be i m p a i r e d . High d e n s i t i e s , however, can s t i l l be a c h i e v e d by i n c r e a s i n g t h e s i t e c o v e r a g e , thus t a k i n g advantage o f development p o t e n t i a l near t h e ground and pushing b u i l d i n g s out toward t h e s t r e e t . B u i l d i n g s w i l l t h e r e f o r e tend t o h o l d the s t r e e t l i n e . F i g u r e 5.3.: Example - 112 -2.5. Maximize D a y l i g h t P o t e n t i a l S i n c e energy used f o r a r t i f i c i a l l i g h t i n g o f o f f i c e b u i l d i n g s r e p r e s e n t s a l a r g e p o r t i o n o f t h e t o t a l energy use, i t i s d e s i r a b l e t o i n c r e a s e d a y l i g h t i n g a s a s u b s t i t u t e f o r a r t i f i c i a l l i g h t i n g . 1 7 A t the p l a n n i n g l e v e l o f s i t e t h e d a y l i g h t p o t e n t i a l i n o f f i c e s can be i n c r e a s e d by a l l o w i n g more space between b u i l d i n g s . In urban a r e a s , however, the economic p r e s s u r e and z o n i n g r e g u l a t i o n s c a l l f o r a d i f f e r e n t s o l u t i o n . The d a y l i g h t i n g p o t e n t i a l f o r a b u i l d i n g c a n be maximized by l o c a t i n g t h e b u i l d i n g mass a l o n g t h e p r o p e r t y l i n e s and c r e a t i n g c o u r t y a r d s and l i g h t w e l l s w i t h i n t h e l a r g e b u i l d i n g s . T h i s i n c r e a s e s t h e p e r i m e t e r a r e a o f b u i l d i n g s f o r e x t e n s i v e use o f d a y l i g h t and, a t t h e same t i m e , a l l o w s h i g h d e n s i t i e s . F i g u r e 5.4.: C o u r t y a r d s f o r D a y l i g h t i n g The d e s i g n o f t h e e x t e r i o r s u r f a c e s and l a n d s c a p e c a n be used to maximize t h e d a y l i g h t p o t e n t i a l i n the l o w e r f l o o r s o f an o f f i c e 19 b u i l d i n g . P a r a b o l i c berms w i t h r e f l e c t i v e s u r f a c e s and water ponds can i n c r e a s e t h e d a y l i g h t r e f l e c t e d i n t o t h e o f f i c e s p a c e . - 113 -Figure 5.5.: Ref lect ive Surface Increases Daylight Potential 2.6. Optimize Potential for Natural Vent i la t ion In low-r ise buildings i t i s desirable to create the potential for natural ven t i l a t i on in summer. Since o f f i c e buildings tend to overheat in summer, the function of natural vent i l a t ion i s mainly to remove warm a i r from the o f f i c e space. Light movement of the a i r can provide a cooling e f fect in o f f i ces i f the incoming a i r i s s l i g h t l y cooler than the surroundings. The temperature of the vent i l a t ion a i r can be influenced by the design of the surface character i s t i c s of the external environment. For instance, vegetation can be used to achieve a cooling e f fect on the a i r . Vegetation draws moisture from the ground and allows i t to evaporate into the surrounding a i r . A body of water would have a 21 s imi la r e f fec t . Natural vent i l a t i on becomes successful when - 114 -prevai l ing breezes fjlow over such vegetation and water areas and then enter the o f f i c e space. This simple p r inc ip le is often used in 22 vernacular architecture. In urban area a i r po l lut ion and t r a f f i c noise can make natural vent i l a t i on impract ica l . In such conditions the bui lding i t s e l f can be used as a ba r r i e r , or ient ing the main spaces away from the streets towards a central courtyard. The internal spaces adjacent to the courtyard can then benefit from an undisturbed environment. However i t i s important that such courtyards are vent i lated and well landscaped. The strategies presented in th i s section require that c l imat i c conditions be taken into account in s i t e planning. In urban areas the strategies for energy-eff ic ient o f f i c e bui ld ing design are often confined to ensuring that the new bui lding design is not 23 aggravating the ex ist ing microcl imatic conditions on a s i t e . - 115 -3. PLANNING LEVEL: LAY-OUT 3.1. Objective 3.2. Thermal Zoning 3.2.1. Perimeter Zone 3.2.2. Core Zone 3.3. Maximize Daylight Potential 3.3.1. Increase of Perimeter 3.3.2. Internal Par t i t ions 3.4. Control Heat Loss and Solar Heat Gain: Buffer Concept 3.5. Control Internal Heat Gains 3.6. Create Potential for Natural Vent i la t ion - 116 -3. PLANNING LEVEL: LAY-OUT  3.1. Objective This section outl ines energy conservation strategies at the level of lay-out design which provide an energy e f f i c i e n t balance between the internal and the external environment. The external environment i s characterized by the c l imat ic elements, that change unpredictably over time (see Appendix A). The internal environment in o f f i c e buildings is largely determined by the high internal heat generation through l i g h t i n g , people and machinery. The internal heat gains are f a i r l y p r e d i c t a b l e . ^ Figure 5.6.: External-Internal Environment - 117 -3.2. Thermal Z o n i n g I t i s g e n e r a l p r a c t i c e t o i d e n t i f y c o r e and p e r i m e t e r zones i n o f f i c e b u i l d i n g s . Both zones have d i s t i n c t l y d i f f e r e n t thermal c h a r a c t e r i s t i c s and a t t e n d a n t energy r e q u i r e m e n t s . - 118 -3.2.1. Perimeter Zone The perimeter zone is characterized by the exposure to the f luctuat ing weather conditions (solar rad ia t ion , temperature and wind) and the potential for dayl ight ing. There are obvious local differences that ex i s t for the perimeter zones as a resu l t of d i f fe rent or ientat ion. For instance solar heat gain i s a minor problem in the perimeter areas facing north, but s i gn i f i can t on west facing surfaces. The depth of the perimeter area depends large ly on the dayl ight penetration. The f l o o r - t o - f l o o r height and the design of the facade, such as amount and type of g laz ing, spandrel design and type of solar control device exercise f i na l control over the day-l i gh t ing potent ia l . A common s ize of the perimeter zone i s 6.00 m, which i s coincident with shallow o f f i c e space or the maximum depth of a c e l l u l a r o f f i c e . Figure 5.8.: Perimeter Zone SECTIOM 6 • oo w\ •-PAVLIM+T CURVE: j REQUI REP LIAHTINA LEVEL ^ - 119 -3.2.2. Core Zone The core i s largely independent of the external cl imate and, dependent upon the extent and a c t i v i t i e s located there, i s always a s i gn i f i can t "generator" of heat. The internal heat gain by a r t i f i c i a l l i g h t s , people and equipment exceed the demand by fa r . Spaces in the core zone generally require cooling for s i g n i f i c an t proportions of the year. The core is e s sent ia l l y remote from the exter io r of the bui ld ing and a c t i v i t i e s in th i s zone cannot benefit from dayl ight. They must invar iably be permanently a r t i f i c i a l l y l i t . I t i s the increased Figure 5.9.: Core Zone 5ECTI0N 6,001^ \ PAVUAHT CURVE ! ' • • ' ' ' • COP.E- • Z-ONE' - 120 -l i gh t ing which contributes the main portion of the internal heat gain. 3.3. Maximize Daylight Potential The strategy of maximizing the dayl ight potential i s analysed under two headings: i ) increase of the perimeter i i ) internal part i t ions 3.3.1. Increase of Perimeter Figure 4.1. indicated that a s i gn i f i cant proportion of energy consumption in o f f i c e buildings is used in the operation of a r t i f i c i a l l i gh t i ng . Since only the perimeter zone can take advantage of d a y l i g h t , 2 5 i t i s suggested to increase the perimeter in order to of fset the a r t i f i c i a l l i gh t ing load. Figure 5.10. shows various approaches how the perimeter can be increased. 2 ^ Figure 5.10:: Increase of Perimeter E 3 PERIMETER mi coe.e A) 6) C.) P) - 121 -However, the increase of perimeter can create a number of undesirable effects and energy penalt ies, i f analysed in a wider framework. In addit ion to causing higher bui lding construction cost, the increase.of the perimeter generally leads to increased heat loss in winter and addit ional solar heat gain in summer. It i s therefore important for the designer to recognize these con-sequences, i f the perimeter is increased. The courtyard bui lding lay-out, i dent i f i ed as d) in Figure 5.10., offers the best potential for maximizing dayl ighting under these r e s t r i c t i on s . 3.3.2. Internal Par t i t ions The dayl ight potential i s also influenced by internal par t i t ions and the se lect ion of the type of o f f i c e lay-out. In open plan o f f i ce s workstations at the perimeter can make d i rect use of day l ight ing, and the a r t i f i c i a l l i gh t ing component can be switched of f i f natural daylight is s u f f i c i en t . In the areas more remote from the perimeter, even small amounts of natural l i g h t are s u f f i c i en t to provide ambient l i gh t ing for the general o f f i c e 28 area and in pa r t i cu la r , for the c i r cu l a t i on areas. In c e l l u l a r o f f i c e lay-outs, indiv idual o f f i ce s are located at the perimeter as a resu l t of prestige and organizational hierarchy in o f f i ce s . This usually prevents valuable dayl ight from entering i n te r i o r spaces. Small bands of glass, reaching from the top of the pa r t i t i on walls to the c e i l i n g , or f u l l y glazed pa r t i t i on walls can maximize the dayl ight potential in c e l l u l a r l ay -out s . 2 ^ In such a way natural ambient l i gh t ing and a view to the outdoors can be provided for the o f f i c e workers in the core zone. - 122 -Figure 5.11.: Daylight Potential and Internal Part i t ions - 123 -3.4. Control Heat Loss and Solar Heat Gain: Buffer Concept Considerable energy savings can be achieved by zoning spaces according, to the i r temperature and vent i l a t ion requirements and locating them re l a t i ve to the warm or cold areas in a bui ld ing. Considerations should be given to the use of cor r idors , equipment spaces, t o i l e t rooms, and other service areas which do not require close temperature cont ro l , as buffer spaces in the north facing parts of a bui lding to reduce heat loss in winter. Rooms with extreme high process heat gain, such as computer rooms, are best placed on northerly exposures with appropriate fabr i c treatment. In the example in Figure 5.12., covered car parking space on the north facade is used as a buffer zone- 3o Figure 5.12.: Parking Space as a Buffer Zone ^0 « - SOOTH ATRIUM OFFICES PAR.KIN4 NORTH —> y - 124 -In o f f i c e bui lding design, however, current space planning is strongly dictated by economies and "prest ige. " From a leasing and marketing point of view perimeter space (especial ly with view) is considered far too valuable to:be relegated to horizontal c i r cu l a t i on space or service area. But ve r t i ca l c i r cu l a t i on may be located external ly or on the bui lding perimeter rather than in the centre of the structure in such a way that i f of fers potential for buffer space.^ With respect to solar heat gains on the east, south and west exposures the buffer concept can be applied s im i l a r l y . However th i s approach requires further measures at the form and fabr ic l e v e l . 3.5. Control Internal Heat Gains Internal heat gains are generated by l i g h t s , people and machinery. The amount of the internal heat gains depends largely on the operation and density in the space. Figure 5.13. shows typ ica l values for o f f i c e bui ld ings, but care should be taken in generalis ing from th i s f igure. Figure 5.13.: Typical Internal Heat Gains PEOPLE 4 8 - 12 W/m2 MACHINERY 4 - 8 W/m2 LIGHTS -A-300 lux 15 - 25 W/m2 500 lux 20 - 35 W/m2 1000 lux 25 - 50 W/m2 - 125 -In large o f f i c e buildings internal heat gains increase the energy expenditures for cooling and vent i l a t ion throughout most of the year. With respect to lay-out planning there are two ways to control the internal heat generation: i ) To subdivide large core areas that require a r t i f i c i a l l i g h t i n g . This approach involves the introduction of courtyards and a t r i a in lay-out planning, i i ) To red i s t r ibute the excess heat from the core to the perimeter zone, where heat is required in the colder seasons. Current design practice acknowledges the advantages of general thermal zoning, but there is l i t t l e attempt to d i s t r i bu te the excess energy around the bui lding without f i r s t returning i t to the centra l i sed system. For instance, leasing subdivisions deter the movement of excess heat around each f l oo r or from f l oo r to f l oo r to meet the d e f i c i t . ^ In th i s context the lay-out of an o f f i c e building can have a s i gn i f i can t ef fect upon the amount of energy required for such a heating and cooling d i s t r i bu t i on system. Long ductwork implies higher construction cost, energy losses and increased energy require-34 ments for fans and pumps. A lay-out that reduces the extent of the d i s t r i bu t i on system leads to operating e f f i c iency and energy conservation. - 126 -3.6. Create Potential for Natural Vent i la t ion In moderate cl imates, such as Vancouver, the outside a i r temperatures from spring to f a l l are quite comfortable. Natural vent i l a t i on can be used for the most part of the year in o f f i c e s . 3 5 However th i s proposition has implications on the lay-out planning of o f f i c e bui ldings. Natural vent i l a t i on can only be used, i f the room depth is l imited to the point where cross vent i l a t ion is possible. Cross vent i l a t i on is determined by the s ize and posit ioning of the openings in a space. 3 6 Large, deep plan o f f i c e buildings must always be mechanically vent i la ted. The problem i s that larger spaces are not cont ro l lab le to the degree required to achieve the desired space condit ion. Deep plan buildings can be divided up in smaller spaces when courtyards or a t r i a are introduced. An atrium lay-out allows a contro l lab le a i r - f l ow from the outside throught the o f f i c e space towards the atrium space, where the a i r i s vented through the roof top. 3 ^ Figure 5.14.: Natural Vent i la t ion in Atrium - 127 -With respect to c e l l u l a r and open plan lay-outs there are two character i s t i c s of natural ven t i l a t i on : i ) Natural vent i l a t ion is more acceptable in c e l l u l a r o f f i ce s in terms of control and user response, since indiv iduals can have d i rect control of operable windows and only one or two people need to be s a t i s f i ed , i i ) Natural vent i l a t i on is more e f f i c i e n t in open plan lay-outs, since no obstructions i n h i b i t the cross ven t i l a t i on . The maximum room depth i s therefore considerably increased. The issues presented in th i s section have been directed at energy and lay-out planning. It has been emphasized that energy considerations have to be included in the i n i t i a l planning stage, where decisions about the p r inc ip le organization of the spaces are made. The planning decisions can then be reinforced and refined on the level of bui lding form. - 128 -4. PLANNING LEVEL: FORM 4.1. Objective 4.2. Reference Buildings 4.3. Heat Loss 4.3.1. Reduce Transmission Heat Loss 4.3.2. Reduce Vent i la t ion Heat Loss 4.3.3. I n f i l t r a t i o n 4.4. Heat Gain 4.4.1. Reduce Solar Gain -Minimize Surfaces -Optimum Orientation 4.4.2. Select ive Treatment of Solar Gains 4.4.3. Optimize Natural Vent i la t ion Potential 4.4.4. Reduce Internal Heat Gains 4.5. Daylighting Design: Maximize Daylighting Potential 4.5.1. Sunlight and Daylight 4.5.2. Window and Daylight 4.5.3. A t r i a - 129 -4. PLANNING LEVEL: FORM 4.. 1. Objectives This section i den t i f i e s energy conservation strategies at the level of form that help to lessen the adverse c l imat i c ef fects and maximize the desirable c l imat ic e f fects . The strategies are directed at the building shape and or ientat ion which both have a s i gn i f i cant influence on the thermal performance of buildings and the i r resu l t ing energy consumption pattern. Form decisions establ i sh the potential for energy e f f i c iency which can be cap i ta l i zed upon with an appropriate use of bui lding materials. 4.2. Reference Buildings In order to examine the effect of some strategies for energy e f f i c i e n t o f f i c e bui lding design with respect to bui lding form a set of f i ve d i f fe rent shaped o f f i c e bui lding types was chosen. The buildings are of ident ica l s i ze , only the exposed area changes. The examined bui lding types would each accommodate 1,800 workplaces. Assuming 13.30 m2 f l oo r area per workstation and a f loor l - to - f loor height of 3.50 m, a tota l f l oo r area of 24,000 m2 and a bui lding volume of 84,000 m resu l t s . This i s comparable to large new o f f i c e buildings currently under construction in Vancouver.^ - 130 -Figure 5.15.: Building Types Examined r^> trj «>J tvj ^ -4 o o .o o ^ ^ ^ 3: ^ ~~ - - ^ <S CO ^ S ® N v « .0^1.^0 /v.' K: — —• N M O ^ . Q ^ N N f° 5$ ^ ^ ~~- ^ ^ " t N csj § § ^ o ^ CQ o-, ^ ^ t — ^r" —• o . o . o . o ^ r - 7 - - - ~ — ^ - ^ - N vo ^ Q J _ «*4 00 cO yo v~> 5 W) K) O 0 ^ ^sl o ^ -o O «N| sj- r^,o-> to .o .o o io <^  • ^- <f is| Q csj c0 *N| tsj LO ^ . VO lO ^ O O O O . O . O *S CD o O IT) ~ -<\J O cO E E S UJ 1 Ui — Ui p 2 3= \r> vO 8 5 S 2 5 5 5 o of -5 3 o o < UJ 3 < UJ o in < < < -J - 131 -The f i ve d i f fe rent bui lding types have the fol lowing characte r i s t i c s : la) and lb) are s ingle storey f l a t bui ld ings, with and without sky!ights. 2) i s a shallow 12-storey bui lding with a t rad i t i ona l room depth of 6.00 m on each side of a cen t r a l , elongated corr idor. This configuration i s quite typ ica l for a speculative o f f i c e block during the 50 1s in Europe; i t i s l i k e l y to be a th in high slab. 3) i den t i f i e s a 6 storey, extremely elongated bui lding of a tota l thickness of 25 m. A double corr idor or "racetrack" lay-out contains two medium-deep o f f i ce spaces and a central zone between the corr idors for ve r t i ca l c i r cu l a t i on and services. 4) is a tower bui lding of 84 m height and 24 f l oo r s . The plan is based on a square of 32 m, thus providing medium to deep o f f i c e space around a central core. 5) shows an almost perfect cubical 12 storey bu i ld ing, based on a square plan of 45 m with predominately deep o f f i ce space. Not only the bui lding configuration d i f f e r s in each of the bui ld ing types, but also a whole set of implications on the bu i ld ing ' s functioning is related to the d i f fe rent forms. Building type 2) has es sent ia l l y l i t t l e mechanical and e l e c t r i c a l equipment. It uses daylight during most of i t s operation time and i t can have natural ven t i l a t i on , even i f there are problems related to the bui ld ing height. On the other hand, bui lding type 5) r e l i e s completely on a r t i f i c i a l support systems, such as l i gh t ing and a i r -cond i t ion ing . The difference can be i l l u s t r a t e d in comparing the i n i t i a l investment - 132 -cost for these technical systems in both bui ldings. Whereas in building 2) only 5% of the construction cost are used for a r t i f i c i a l l i g h t i n g , bui lding 5) uses about 30% for the l i gh t i ng and a i r -conditioning system. The expenditures for operating the two buildings are in a s imi la r order of magnitude, i f not more d i f f e ren t . In the fol lowing sections the f i v e bui lding types are considered under the headings "heat loss" and "heat gain." 4.3. Heat Loss In cold climates heating represents the most s i gn i f i can t component of the overal l energy consumption in o f f i c e bui ld ings. The heating requirements can be attr ibuted to.three main areas of heat loss: i ) heat loss through transmission,39 i i ) heat loss through ven t i l a t i on , i i i ) heat loss through i n f i l t r a t i o n . The basic strategy of minimizing heat loss can be further ref ined according to these i dent i f i ed three areas. 4.3.1. Reduce Transmission Heat Loss The rate at which heat is conducted through the bui lding skin is a function of: i ) the exposed area of a bui lding (roof, e levat ions, ground), i i ) the thermal properties of the building skin (U-value), i i i ) the temperature difference between the ins ide and the outside a i r . - 133 -For a bui lding skin with homogeneous insulat ion properties heat loss i s a d i rec t function of the exposed area. As a consequence, any reduction of the exposed surface area w i l l reduce the heat loss. This leads to the simple conclusion that i t i s always useful in energy terms to reduce the overal l volume of a bu i ld ing. In th i s context i t i s appropriate to re-evaluate some o f f i c e space standards in terms of energy e f f i c iency . However, i t must be recognized that space standards for workplaces are pr imar i ly defined by functional c r i t e r i a and statutory requirements, which give already minimum l i m i t s for a good working environment. Opportunities to reduce the f l oo r areas and the bui lding volume are more s i gn i f i can t in service areas, such as c i r cu l a t i on space, mechanical plant rooms and service voids. In o f f i c e bui ld ings, these areas contribute substant ia l ly to the overal l volume of the bu i ld ing. If the volume is kept constant and the exposed surface area is minimized, building form changes. Of a l l rectangular bui lding forms, the cube is the form with the least amount of surface a r e a . ^ The re l a t i on of heat loss and bui ld ing form i s presented in Figure 5.16. - 134 -Figure 5.16.: Heat Loss and Building Form 6UU.DIM4 type IA 16 2 3 4 5 I HEAT LOSSES BY CONDUCTION FOB. PIFFEEENT BWLplN^ FO^MS OW A 'COLD IUIMTER PAY (2'/i.%) IN VAhiCOUVSR, - 135 -These calculat ions are based on a cold winter day in Vancouver, in which the effects of solar radiat ion are ignored. The outdoor temperatures are -7°C for the a i r and +10*C for the ground.^ The indoor temperature is assumed +20"C. The l e f t hand scale indicates the heat loss in Megawatt for the ent i re bu i ld ing , and the r ight hand scale gives the heat losses per square meter f l oo r area. Figure 5.16. shows that within the realms of normal practice (building type 2 to 5) the percentage decrease in fabr ic heat loss i s not marked. As a general r u l e , however, i t can be stated that the more compact the bu i ld ing, the less the heat loss. The ef fect of the window area, as represented by an increase in the overal l fabr ic heat transmission or Uc-value, i s s i gn i f i c an t . As the overal l U 0-value of the fabr ic i s increased from 0.5 to 2.0 W/m2"C, the r e l a t i ve differences in heat loss of the d i f fe rent forms becomes more pronounced. Conversely, i f the fabr ic i s well insulated, the differences are neg l ig ib le . It should be noted that vent i l a t ion heat loss i s not included in Figure 5.16. The effect of vent i l a t ion is analysed in the fol lowing section. - 136 -4.3.2. Reduce Vent i la t ion Heat Loss Vent i la t ion requires replacing the warm a i r with cooler outside a i r during the heating season, and therefore represents a s i gn i f i cant heat loss. The vent i l a t i on heat loss depends on: i ) number of a i r changes per hour, i i ) volume of the space, i i i ) spec i f i c heat of the a i r , iv) temperature d i f f e r en t i a l between inside and •replacement a i r . In order to minimize heat loss the vent i l a t ion rate or the volume of the space should be reduced. However, there are pract ica l and physiological l im i t s to reduce the vent i l a t i on rate. The proposed "Measures for Energy Conservation in New Buildings" s t ipu late 17.0 m3/h person as acceptable.^ 3 With respect to bui lding form heat loss through vent i l a t ion i s reduced when the exposed area and the bui lding volume is minimized. If the vent i l a t i on rate is low th i s l a t t e r factor becomes dominant. Natural ven t i l a t i on through operable windows generates considerable heat losses in winter. Natural v en t i l a t i on , using a vent i l a t i on rate of two a i r changes per hour, would increase the heat loss indicated in Figure 5.16. by about 80 W/m . In the t a l l bu i ld ings, exposed to higher wind speeds, i t i s often not possible to use natural vent i l a t i on because of draughts, aerodynamic noise 44 or internal stack e f fect s . Mechanical vent i l a t i on systems are invar iably always necessary. By contrast in buildings of medium height, the potential ex ists for natural v e n t i l a t i o n . 4 5 In central - 137 -urban areas, high levels of t r a f f i c noise and atmospheric po l lut ion make th i s an undesirable solut ion as i t resu l ts in a considerable reduction in sound transmission and the admittance of dust and f 46 fumes. However even though the potential may ex i s t , the use of natural vent i l a t ion mechanisms during the winter may not be desirable in terms of energy e f f i c i ency . Natural vent i l a t i on is random in nature and can vary between minimal to excess amounts depending upon the a i r pressure d i f f e r e n t i a l between the external face and the building i n t e r i o r . Overall excessive amounts of fresh a i r w i l l be introduced into the space with the attendant increase in heat loss. Natural vent i l a t i on precludes the simple heat exchange recovery systems. 4.3.3. I n f i l t r a t i o n I n f i l t r a t i o n is unintentional a i r leakage through a bu i ld ing ' s sk in. I n f i l t r a t i o n of cold outside a i r into an o f f i c e bui lding can be responsible for as much as 25% of the yearly heating requirements. 4 7 It cannot, l i k e vent i l a t i on systems, be turned o f f at night or during weekends. I n f i l t r a t i o n varies considerably from bui lding to bui ld ing. The differences encountered resu l t from: i ) cracks around doors and windows i i ) doors that are opened for entry or ex i t from a bui lding i i i ) openings in the bui lding envelope, such as badly f i t t i n g dampers - 138 -iv) construction jo in t s between indiv idual panels in a wal 1 v) porous material used in building construct ion, such as concrete blocks without a coating. I n f i l t r a t i o n is caused by two d i f fe rent factors: wind e f fect and stack e f fect . Wind ve loc i ty impinging on one side of a building leads to i n f i l t r a t i o n into the bui lding on the windward side. On the leeward s ide, however, a negative pressure is created which leads to e x f i l t r a t i o n of a i r on th i s s ide. Beside the wind cha rac te r i s t i c s , the shape of the building and i t s surrounding.(landscape, adjacent 48 buildings) a f fect th i s type of i n f i l t r a t i o n . Stack ef fect i s always a problem in t a l l bui ldings. The density difference between the warm a i r inside the bui lding and the cold a i r outside causes outside a i r to leak into the lower part of the bui lding and to leak out at the top. Stack ef fect becomes more pronounced as the bui lding height increases. The ef fect of the bui lding form on i n f i l t r a t i o n is shown in Figure 5.16. The plan aspect ra t i o i s the r a t i o of the bui lding length to the building depth. Figure 5.17. shows that bui lding form which deviate from the square plan form have a substantial increase in i n f i l t r a t i o n heat loss. - 139 -The e f f e c t o f t h e b u i l d i n g h e i g h t on i n f i l t r a t i o n i s p r e s e n t e d i n F i g u r e 5.18. The e f f e c t s o f i n f i l t r a t i o n a r e i n c r e a s e d as t h e b u i l d i n g p r o t r u d e s i n t o a r e a s o f h i g h e r wind speeds. However, the d i f f e r e n c e s a r e l e s s marked f o r b u i l d i n g s i n c i t y c e n t r e , s i n c e t h e s u r r o u n d i n g b u i l d i n g s moderate the i n f l u e n c e o f t h e wind. F i g u r e 5.18.: B u i l d i n g H e i g h t and I n f i l t r a t i o n ? ^ 140 4.4. Heat Gain For buildings which have r e l a t i v e l y low internal heat gains, such as res ident ia l bui ld ings, i t i s desirable to introduce solar gains during the colder seasons. For buildings which have r e l a t i v e l y high internal gains, such as o f f i c e bui ld ings, the necessity to increase the winter solar gain is less c r i t i c a l . Large o f f i c e buildings have a tendency of overheating even in winter conditions due to the internal heat gains. Figure 5.19.: Internal Heat Gains Af fect ing Heating Demand MW 1,8 ! 1,0. I , 0.8 -J ! 0,4 i O.Z -I I tattoo* = +2.0 "C t 0 O T » 0 0 « = - J °C +«M>lM» •» -HO 'C • Uo = Z , o * • / • * . * * • INTERNAL W£AT USHUA OWIAHT - 6o _ 5o \- 3o \- 2-0 V ID - 141 -Figure 5.19. shows that in some cases in winter the internal heat gains are in excess of the heat losses through the f ab r i c . This i s largely caused by the a r t i f i c i a l l i gh t i ng which i s used as an addit ional heat source. The dotted l i n e in Figure 5.19. indicates the internal heat gains i f dayl ighting i s used instead of a r t i f i c i a l l i gh t ing whenever feas ib le . However, by far the most c r i t i c a l condition in large o f f i c e buildings is one of avoiding excessive heat gains during the summer. This can be achieved by various s t rateg ies: i ) , to reduce solar gains by reject ing the solar radiat ion before i t enters the bui ld ing. Compact form and proper or ientat ion are the main features of these strategies. i i ) to select the solar gain by using the buffer concept i i i ) to optimize the natural vent i l a t ion potential iv) to reduce internal heat gain. - 142 -4.4.1. Reduce Solar Gain Solar gain can be reduced by minimizing the bui lding surfaces (wall and window areas) presented to the sun, and by choosing an appropriate or ientat ion. Minimizing Surfaces Figure 5.20. shows the heat gains for f i ve bui lding types with ident ica l volume. The calculat ions are based on c l imat ic data of AO 5Q Vancouver on a warm summer day. ' The or ientat ion of the main fenestrat ion areas is north-south. The lowest part of each column indicates the heat gains by people, l i gh t s and machinery. The middle part shows the fabr ic heat gains, and the triangular-shaped top part indicates the solar gains, e ither for c lear sky or for a 100% cloud cover. The f igure shows that i f the building is compact and the glazing reduced, then the potential for solar heat gain problems w i l l be reduced. Deviations from the basic cubic form and changes of the fenestration area w i l l resu l t in a corresponding increase in the s ign i f icance of or ientat ion as a factor . - 143 -Figure 5.20.: Summer Heat Gains MW W/rt OOODQOD •ooooaoDoaoo DQODOOODO •OQ  •oooaooaoooa ooooooooaooo loo r So 1- 0 BUILDING IA IB SOLAR CLEAR 3Ky -CLOl/P COVER TRANSMISSION (CONDUCTION) HEAT 4AIN5 Y//Ji INTERNAL HEAT 4AlNS ( PEOPLE , EQUIPMENT, LIGHTS) - 144 -Optimum Orientation Solar rad iat ion i s a dynamic element. It changes both in 51 magnitude and d i rec t ion throughout the day and the year. The form of a building w i l l therefore be s i gn i f i can t in determining which surfaces are presented to the sunpath at d i f fe rent times. Figure 5.20 shows the solar radiat ion incident upon d i f f e ren t l y oriented surfaces over the period of a year for the l a t i tude of Vancouver (49.5°). Clear sky condition is assumed. Figure 5.21. indicates that east and west facing surfaces receive the greatest amount of solar radiat ion during the summer. Surfaces facing south receive highest solar gains in spring and f a l l . During summer the value decreases substant ia l l y . Figure 5.21.: Theoretical Clear Sky Radiation Data for Vancouver A r e a . 5 2 0 F M A M 3 3 A S O N P MONTH - 145 -The or ientat ion of a bui lding has a s i gn i f i cant ef fect on solar gain.. As a general ru le , those o f f i ce buildings which are elongated along the east-west axis have the greatest amount of so lar gain in winter and the least in summer, when cooling is required. Using bui lding type 2 as an example, i t can be shown that the bui lding oriented along the north-south axis receives twice as much solar gain 53 in the middle of summer as i f oriented east-west. Figure 5.22.: Solar Gain and Orientation &ULLDIN4 T/PE 2 2 . 7 9 MEGAWATT/h 1.46 MEGAWATT/h Consequently, east and west facing surfaces should be reduced in area, since they contribute most s i g n i f i c an t l y to the solar gain. South facing surfaces can be increased in s i ze , since they receive the greatest amount of solar gain during winter, but not as much in summer. Building surfaces with l i t t l e or no fenestrat ion should therefore be oriented towards east and west. This approach es sent ia l l y generates o f f i c e areas oriented e i ther north or south, which can be - 146 -s p e c i f i c a l l y dealt with on the fabr ic l e v e l . Square types of o f f i c e buildings can be oriented with the i r diagonal axis west-east, so that the main fenestration areas.face southwest and southeast (see also Appendix B). 4.4.2. Select ive Treatment of Solar Gains The approach of compact bui lding form with reduced glazing i s c l ea r l y a manifestation of c l imat ic re ject ion . The problem reverts to one of dealing with i n te rna l l y generated heat gain, heat recovery and the d i s t r i bu t i on of energy around the bui ld ing. If the form deviates from the cubic and where glazing area i s increased (see l a t e r ) , i t i s important for the designer to be consistent in fol lowing the implications of th i s act ion. Obviously or ientat ion becomes more s i gn i f i can t . However cont ro l l ing the solar gains transmitted through the fabr ic becomes a s i gn i f i can t issue. Because occupants are constrained to f ixed workstations, solar gains cannot be useful ly admitted d i r e c t l y into the i n t e r i o r . Therefore i t i s necessary to introduce solar gains ( i f desired) i nd i r ec t l y . This involves creating a buffer zone between the bui lding skin and the occupied space, in which the solar gain can be trapped, d i s t r ibuted and integrated into the buildings mechanical system. In conceptual terms, not only is the external fabr i c climate se lec t i ve , but there is an inner skin which is also climate se lec t i ve , as shown in Figure 5.23. The intervening zone can include the ce i l i n g plenum. - 147 -Figure 5.23.: Buffer Zone i m III y [ v * I Q i ^ ^ ^ ' ^ The strategy of the buffer zone has been used in the design of the Hooker Off ice Building in Niagara F a l l s , New York . 5 4 The double skin is the most prominent "energy feature" of th i s cubic shaped o f f i c e bui ld ing. The buffer zone performs as an unconditioned thermal zone which changes energy requirements of the bui ld ing from heating dominated to cooling dominated, as shown in Figure 5.24. The double skin reduces the impact of extreme outside temperatures and eliminates e f f e c t i ve l y i n f i l t r a t i o n . The substantial energy savings for the bui lding (as designed) becomes apparent when the design is compared to conventional designs without energy conservation measures. - 148 -F i g u r e 5.24.: Energy E f f i c i e n c y through Double S k i n 5 4 AREA DAYLIT EFFECTIVELY OFFICE AREA (CONDITIONED) —UNCONDITIONED BASEMENT THERMAL ZONING: HOOKER CHEMICAL BUILDING COOLING LOAD FOR "CONVENTIONAL" BUILDING 7 6 11 11 27 47 _55 5 i COOLING LOAD FOR BUILDING AS DESIGNED 42 33 30 18 HEATING LOAD FOR BUILDING AS DESIGNED 4 16 30 HEATING LOAD FOR "CONVENTIONAL" BUILDING J A N F E B M A R A P R M A Y J U N J U L A U Q S E P O C T N O V D E C In r e s p e c t t o t h e b u f f e r c o n c e p t and t h e c e i l i n g plenum i t i s p o s s i b l e to i d e n t i f y a f u r t h e r i m p l i c a t i o n t o form. The c e i l i n g plenum, the f l o o r t h i c k n e s s and f l o o r t o c e i l i n g h e i g h t c o n s t i t u t e t he f l o o r - t o - f l o o r h e i g h t . Whereas the f l o o r t h i c k n e s s i s d e t e r m i n e d by c o n s t r u c t i o n and c o n s t r u c t i o n a l c o n s i d e r a t i o n s , t h e f l o o r t o f l o o r h e i g h t i s m a i n l y d i c t a t e d by economics and code r e q u i r e m e n t s . A l t h o u g h an i n c r e a s e i n t h i s d i m e n s i o n would have t h e p e n a l t i e s o f i n c r e a s e d c o s t s i n m a t e r i a l s and exposed s u r f a c e a r e a f o r h e a t t r a n s m i s s i o n , i t does p e r m i t a g r e a t e r c e i l i n g plenum. In terms o f i n c r e a s i n g t h e e f f i c i e n c y o f t h e m e c h a n i c a l system i n moving e n e r g y a r o u n d t h e - 149 -bui ld ing, th i s may provide the opportunity to e f fect s i gn i f i can t energy savings. Typ ica l ly an increase in f l oo r to f l oo r height of 15 cm would permit greater volumes of a i r to be moved with smaller pressure drops and hence permitting reduced fan horsepower. 5 5 4.4.3. Optimize Natural Vent i l a t ion Potential In contrast to winter condit ions, where natural ven t i l a t i on creates excessive heat loss , i t i s desirable to take advantage of natural vent i l a t ion during summer when the potential ex i s t s . However, the same re s t r i c t i on s with respect to a i r po l lut ion and t r a f f i c noise, as mentioned above, have to be acknowledged. Natural vent i l a t i on is not appl icable in compact bui ld ing forms. The concept of natural vent i l a t i on requires courtyards within such large buildings in order to create natural a i r flow patterns through the structures. 4.4.4. Reduce Internal Heat Gains Internal heat gains contribute substant ia l ly to the cooling load in o f f i c e bui ldings. The major portion of a l l internal heat gains can be attr ibuted to l i gh t ing (see Figure 5.13). Therefore, l i gh t ing represents the s ingle largest end use of overal l energy use in o f f i c e bui ldings. - 150 -F i g u r e 5.25.: Energy Use o f L i g h t i n g However, i t s h o u l d be noted t h a t a complex i n t e r r e l a t i o n s h i p e x i s t s between t h e v a r i o u s energy r e q u i r e m e n t s f o r o f f i c e b u i l d i n g s . L i g h t i n g o f f s e t s t h e h e a t i n g demand d u r i n g t h e w i n t e r , as i d e n t i f i e d i n F i g u r e 5 . 1 9 . 5 7 C o n v e r s e l y , l i g h t i n g s i g n i f i c a n t l y c o n t r i b u t e s t o t h e c o o l i n g l o a d d u r i n g summer. F i g u r e 5.26.: I n t e r r e l a t i o n s h i p H e a t i n g / C o o l i n g / L i g h t i n g •vl COOLIN^ I ( L I 4 H T I N 4 ji —(WINDOW J - 151 -As more e f f i c i e n t l i gh t ing procedures are developed (task 1ighting/daylighting etc.) obviously the interre lat ionsh ips w i l l change. This again reinforces the point of making design decisions based upon the current breakdown in o f f i c e use. In many instances the reduced l i gh t ing load w i l l transform the 'energy' problem from one of cooling/heating to purely one of heating. This change in emphasis w i l l lead to a d i f ferent de f i n i t i on of the design problem and associated design response. Strategies to reduce the internal heat gains were given under the t i t l e of energy management. In th i s respect the reduction of power for a r t i f i c i a l l i gh t ing carr ies the greatest po tent i a l , since every two kwh of l i gh t i ng require about one kwh of a i r - cond i t ion ing . With respect to bui lding design there is e s sent ia l l y one basic strategy to reduce internal heat gains. It i s the strategy to maximize the dayl ight capab i l i t y of the bui ld ing. Figure 5.27. shows the potential reduction of the heat gains by the l i gh t ing system i f dayl ighting is used and i f more e f f i c i e n t management of the l i gh t ing system i s applied. - 152 -Figure 5.27.: Reduction of Lighting Heat Gains 59 HEAT 4AIMS w/ 3o -2.0 -Io -[••••••••••a [] MA laOOPODODOOOOl OO QOooonoool km m m 18 i 3 + S REDUCTION WHEN PAYLI4HT IS U5Ep REDUCTION WHEN EFFICIENCY OF LIAHTIN* &YSTEH IS IMPKOUED HEAT OF LI4UT5 WHEN DAY/.WHTIN4 15 USEP ANP EFFICIENCY IS IHPKOVEf) The diagram indicates in a generalized way that the dayl ighting potential for the shallow bui lding type 2 and for the bui ld ing with extensive fenestration (type IB) i s highest. Even in compact bui lding forms the potential to reduce internal heat gains by l i gh t s i s considerable when perimeter l i gh t ing i s used.^O On the other hand, the potential for reductions by management decisions i s more pronounced in the compact bui lding forms, whereas i t i s r e l a t i v e l y small in the shallow bui lding type. Combining both, day-l i gh t ing strategies and strategies for e f f i c i e n t management resu lts in reductions of 50-90% of the tota l heat generation by l i g h t s . - 153 -5.5. Daylighting Design: Maximize Daylighting Capab i l i t ie s of Bui 1 ding  Figure 5.25 indicated that a s i gn i f i can t proportion of energy consumption .in commercial buildings is used in the operation of a r t i f i c i a l l i g h t i ng . In response to th i s recognit ion, early energy conservation checkl i s ts were advocating an increased use of natural l i g h t i n g . However, since there had not been any widespread use of dayl ighting techniques for more than 20 years, the design profession were unable to confidently respond to th i s pa r t i cu la r recommendation. The response was made pa r t i cu l a r l y d i f f i c u l t by the apparent contradictions for reduced glazing area for heat loss/ gain reasons appearing in the same check l i s t s . 6 ^ The circumstances under which one would increase or decrease the glazing are, of course, dependent upon the par t i cu la r bui ld ing type and context. Now that the interre lat ionsh ips between the various energy uses are recognized, current research i s seeking to explore the circumstances in which dayl ight ing can be used to ef fect overal l energy savings. In pa r t i cu l a r , attent ion i s directed towards the use of dayl ighting in commercial buildings which are^primari ly used continuously throughout the daytime period. Results to date c l ea r l y indicate that consideration of dayl ighting in overal l energy balances a l te r s the determination of optimum window area toward larger windows than one would predict from the thermal performance alone. - 154 -Using dayl ight as a replacement for a r t i f i c i a l sources offers obvious energy savings. However i t i s fal laceous and dangerous in bel ieving that good dayl ight practice simply means the use of large windows and that large windows guarantee s i gn i f i cant energy savings. 4.5.1. Sunlight and Daylight A l l natural l i gh t ing originates from the sun. Two basic c l a s -s i f i c a t i on s can be made - sunlight and dayl ight. Sunlight i s c l a s s i f i e d as the d i rect sunlight entering the space. This obeys the laws of sunlight geometry and has the attendant problems of solar gains. f i2 Daylight is that component of the solar beam that i s scattered by constituents within the atmosphere. This d i f fuse l i g h t comes from the ent i re sky vault but is not evenly d i s t r i bu ted . During overcast sky conditions the sky is three times brighter at the zenith than at the horizon and uniform in azimuth. During c lear sky conditions the d i s t r i bu t i on is more complex, being brighter in the v i c i n i t y of the sun and fol lowing an uneven pattern, in azimuth. Although sunlight penetration leads to higher internal l i gh t ing l eve l s , i t s attendant problems of solar gain, c o n t r o l l a b i l i t y and propensity to create glare and excessive contrast reduce i t s d e s i r a b i l i t y in many bui lding types. An increase in the glazing area can potent ia l l y create a number of undesirable environmental factors and energy penalt ies. Current developments in dayl ight design are attempting to maximize the dayl ight penetration without the attendant problems. Two basic - 155 -approaches can be i d e n t i f i e d ; the f i r s t involves the examination of the window system and the second general d i rect ion involves the use of a t r i a . 4.5.2. Window and Day!ight In t rad i t i ona l window design the amount of dayl ight f a l l s o f f rap id ly from the window wa l l . The distance can be extended by using systems, which r e f l e c t dayl ight of f the window deeper into space. Several developments are occurring in th i s a r e a . 6 3 , 64 Figure 5.28.: Beam Daylighting - 156 -Beam dayl ighting is a l i gh t ing concept that uses ref lected beam radiat ion from the sun and the d i f fuse dayl ight component of sun-l i g h t . The sunlight is ref lected on s i l vered Venetian bl inds in the window system and is directed onto the high r e f l e c t i v e c e i l i n g of the o f f i c e space, so as to i l luminate space as deep as 12.00 m. The c e i l i n g acts as a d i f fuse re f l ec to r providing normal d i f fuse i l luminat ion deep inside the space. A r e l a t i v e l y small glazed area of 60 cm height near the c e i l i n g of a standard window admits enough l i g h t throughout the year to provide s u f f i c i en t natural l i gh t ing levels a f ter r e f l ec t i on from the c e i l i n g . Below the beam dayl ighting apparatus, the device that beams the l i g h t into the space, a conventional exter ior shading device may be used to protect the lower section of the window. The most important element of the beam dayl ighting method i s the apparatus that r e f l ec t s the l i g h t onto the c e i l i n g . There is a great var iety of d i f fe rent designs: r e f l e c t i v e Venetian b l inds , mirrors, l i ght - she lves , l ight-scoops, e t c . 6 5 Some of them can act simultaneously as shading device, i f properly integrated in the bui Iding.. design. - 157 -Figure 5.29.: Beam Daylighting Apparatus MIRROR LI4HT - .SHELVE LIAHT --3COOP In th i s approach the window system i s therefore providing a number of functions simultaneously - but the important point is that these functions are recognised and dealt with s p e c i f i c a l l y . 6 6 There s t i l l remains a series of control problems to be resolved for dealing with the dynamic character of natural l i g h t . The amount and source of l i gh t change constantly; the incident angle changes, too. This requires a dynamic design response which is spec i f i c to time and place. However th i s concept is extremely compatible with the development of a buffer zone described ea r l i e r for dealing with solar heat gain and i t s movement around the bui ld ing. - 158 -Figure 5.30.: Daylighting 4.5.3. A t r i a With respect to dayl ighting and form, i t becomes obvious that massive buildings with a r e l a t i v e l y small amount of usable perimeter o f f i c e space and large i n te r i o r window!ess spaces do not lend them-selves to extensive dayl ight ing. In day l ight ing, the more perimeter, the greater potential for introducing dayl ight. This shallow bui ld ing form which would resu l t from th is approach is contrary to two strongly determinant factors. The centra l i sed compact forms have been generated by the pressures of high urban land costs, increase in bui lding costs, business organisational requirements, e f f i c iency of systems, etc. and, in part, by an overly s imp l i s t i c energy con-servation der ivat ive to minimize the external surface area. - 159 -Figure 5.31.: Atrium vs. Highrise TIP SECTION: TOPICAL HI4H RISE SECTION : ATRIUM H i s t o r i c a l l y , the central court of a Roman house, the atrium, has been used as a dayl ighting concept by simply extending the amount of exposed wall a rea . 6 ^ However, the potential of the atrium in energy terms extends beyond for the single benefit. An atrium provides an improved c l imat ic buffer zone and thereby increases the p o s s i b i l i t y of year round use and natural ven t i l a t i on . This par t i cu la r approach is only appl icable to buildings less than about f i v e storeys. For the open courtyard, the increase use of daylight leads to a potential reduction in the l i gh t ing component (and a small reduction in cooling load). For mid to cold climates the increase in exposed surface area would have an attendant increase in heat loss. However th i s would be mo l l i f i ed to an extent by the improved microclimate. Computer simulations indicate that i f the atrium i s covered, the energy consumption w i l l be further reduced by approximately 25 per cent from the uncovered s i t u a t i o n . 6 9 - 160 -The obvious advantage of an enclosed atrium i s the combination of dayl ighting pr inc ip les with a compact bui lding form. The atrium replaces two exter ior walls with one roof, thus reducing the amount of exposed bui lding surfaces. The buffer zone created i n te rna l l y provides the opportunity for moderating solar gains, providing natural vent i l a t i on and a preheating zone for vent i l a t i on a i r . Two p o t e n t i a l c o n f l i c t s appear i n the use o f t h e c o v e r e d a t r i u m . The f i r s t i s d e a l i n g w i t h t he p o t e n t i a l c o n f l i c t between e x c e s s i v e s o l a r heat g a i n d u r i n g t he summer and t h e e x t e n t t o which any s o l a r c o n t r o l d e v i c e s w i l l r e d u c e t h e a v a i l a b i l i t y o f d a y l i g h t . Any s o l a r c o n t r o l d e v i c e s s h o u l d t h e r e f o r e be o p e r a b l e t o t h e e x t e n t o f r e s p o n d i n g t o t h e dynamic movement o f t h e sun. In t h i s a r e a t h e r e i s tremendous scope f o r i n g e n u i t y . The second problem r e l a t e s t o the i n s t i t u t i o n a l r e s t r i c t i o n s t o t h e use o f e n c l o s e d a t r i u m s . The N a t i o n a l B u i l d i n g Code c u r r e n t l y r e g u l a t e s ( s u b - s e c t i o n 3.2.9.) on openi n g s t h r o u g h f l o o r a s s e m b l i e s ( a t r i a ) as a r e s u l t o f f i r e s p r e a d p r o t e c t i o n . ^ 2 The r e s t r i c t i o n s - 162 -es sent ia l l y apply to large open spaces more than one storey high within a high r i se bu i ld ing, and l i m i t both height and access. Before development of the atrium concept can be furthered, there w i l l have to be a rev i s ion to th i s par t i cu la r section of the Bui lding Code. The issues presented in th i s section have been directed at energy and bui lding form. The emphasis has been one of ident i fy ing that energy considerations present the designer with considerable scope for innovation rather than imposition. Whatever the i n i t i a l stance the designer takes concerning form, i t w i l l create a potential which must be reinforced at the fabr ic l e v e l . - 163 -5. PLANNING LEVEL: FABRIC 5.1. Objective 5.2. Window Design Strategies 5.2.1. Exter ior: Consider Orientation 5.2.2. Exter ior Accessories: Control Solar Gain 5.2.3. Window Glass: Minimize Heat Loss, Minimize Solar Gain  and Provide Daylight 5.2.4. Inter ior Accessories: Control Natural Light 5.2.5. Inter ior : Cap i ta l i ze Upon Daylight Potential and Upon  Select ive Treatment of Solar Gains 5.3. Wall Design Strategies 5.3.1. Insulation: Minimize Heat Loss 5.3.2. Thermal Capacity: Increase Thermal Mass 5.3.3. Exter ior Colour and Texture: Reduce Heat Gains 5.4. Roof Design Strategies - 164 -5. PLANNING LEVEL: FABRIC  5.1. Objective This section outl ines energy conservation strategies for f ab r i c design that aim at a closer match between the bui lding and the prevai l ing cl imate. Fabric design involves the determination of the wall and fenestration areas of a bui ld ing and the se lect ion of the bui ld ing materials. The fabr ic es sent ia l l y separates d i f fe rent kinds of climate regimes: ^3 i ) the prevai l ing meteorological climate which can be analyzed but not control led by man, and i i ) the internal climate dictated by user comfort require-ments. Figure 5.34.: Fabric as a Cl imatic Modif ier - 165 -The bui ld ing fabr ic should act as a f i l t e r , not simply as a barr ier . The fabr ic should be considered as an operable element, dynamically involved in the act of re jec t i ng , receiving or moderating the environmental impact. The importance of f ab r i c design becomes most apparent when no appropriate measures have been taken at e a r l i e r planning stages to moderate the adverse effects of the external environment. These adverse effects may in f ac t have been i n ten s i f i ed by the inadequate treatment of the bui lding sk in. Where th i s i s the case, they then have to be modified by the mechanical systems with an attendant increase in energy use. 5.2. Window Design Strategies Over the past decades the amount of window area in o f f i c e buildings 74 has s teadi ly increased. The window i s the most c r i t i c a l factor in fabr ic design. Windows, besides providing visual transparency, have a several times higher heat loss or heat gain than wall areas. In window design a var iety of options are ava i lable to cope with the sens i t ive character of windows. The amount of window area, the or ientat ion of windows and the posit ioning are the main areas that have to be considered. - 166 -The basic functions of a window are: i ) to allow dayl ighting i i ) to provide a view i i i ) to reject summer heat gain iv) to provide winter heat gain ( i f so desired) v) to provide thermal and acoustical insu lat ion v i ) to remain a i r t i ght v i i ) to allow natural vent i l a t ion ( i f so required) The var iety of window functions makes proper window design . 75 d i f f i c u l t . No s ingle function can be i so lated without a f fect ing the other functions. This complex in ter re la t ionsh ip becomes apparent i f a pa r t i cu la r function i s overemphasized in a design. An example is the extreme reduction of window area in order to achieve a better thermal insu lat ion of the bui ld ing skin in winter. Such an over-emphasis w i l l have a drawback in other areas: dayl ighting would be cur ta i led severely and the view would be inh ib i ted. The window can be considered as a system with the fol lowing parts: i ) exter io r i i ) exter ior accessories i i i ) window glass iv) i n t e r i o r accessories v) i n t e r i o r - 167 -Figure 5.35.: The Window System \ '.I EXTER\&R Jt EXTERIOR MX£30«.\Eb J& WINDOW ALAS5. E INTERIOR ACtEi&SORltS , I INTE-|?\OR Each part of the window system offers opportunities to influence the environmental conditions of the internal space. Table 5.1. iden t i f i e s on a broad level a var iety of such opportunities and shows the i r re lat ionsh ip to the window functions. However, i t i s important to stress the fact that these relat ionships are dependent on the llocal cl imate, the time of the day and the season, and the spec i f i c design of the architectura l features. In th i s section only a few aspects of the var iety given in Table 5.1. are discussed. For each part of the window system the main design strategy i s outl ined and i t s impl icat ion i s explained. - 168 -Table 5.1.: Window System Design Solar Day- Shading Insula- A i r t i g h t Vent i - View Heating 1ighting t ion -ness l a t i on I. Exter ior Orientation to sun X X Orientation to wind X Windbrakes X X X c Ground surface X X Vegetation c X X X X II Ext. Accessories Screen c X X c Roll binds c X X c Arch, projections c/x X c Ext. shutters c X X X c Awnings c X III Glass and Frame Reduced glazing X c X X c Mult ip le glazing X Heat absorbing glass c X c Ref lect ive glass c X c Window t i l t X X Type of operation X X Thermal break X IV Int. Accessories Venetian blinds X X c Drapes c X X c Roll shades X c X c Insulating shutters X c V Inter ior Light colours c X Task 1ighting X Light controls X Thermal mass X Key: x important r e l a t i on ; pos i t ive e f fect c . re lat ion which can act counter-productive to suggested function - 169 -On the ex te r i o r , where adverse c l imat i c forces can be mitigated and benef ic ia l factors can be selected, the or ientat ion is the . c r i t i c a l var iable in making window design decisions. The exter ior accessories are best suited to support the strategy of cont ro l l i ng solar heat gain before i t enters the space. The window i t s e l f determines to a large degree.how successful the strategies of minimizing heat loss in winter and minimizing solar gain in summer can be implemented in the bui lding design. The window s i ze , i t s pos i t ion and the type of glazing are the main var iables. The internal accessories supplement the potential of the window. The main concern here i s to maximize the dayl ight potential and to regulate the attendant problems of sun glare and visual discomfort. The design of the i n t e r i o r can be used to insure that optimum benefit i s derived from the energy assets the window provides. In pa r t i cu l a r , the dayl ight potential provided by the window can be cap i ta l i zed upon with an appropriate design of the internal surfaces. For the arch i tect i t i s important to decide which strategies should be given p r i o r i t y . This decis ion must be based on e a r l i e r planning decisions in s i t e , lay-out and form design. The arch i tect must be consistant in fol lowing a par t i cu la r idea through a l l levels of design. Fa i lure to fol low each aspect through and to appreciate resu l t ing consequences w i l l lead to an unsatisfactory working environment. 7^ In th i s context the re lat ionsh ip between the design strategies has to be considered. The importance of maximizing dayl ight ing has been emphasized e a r l i e r . However several measures important in - 170 -cont ro l l i ng solar gain reduce the dayl ight potent ia l . Obviously designing for dayl ight has i t s impl icat ion on the way one deals with solar gain in summer. Therefore the designer has to be aware of the p r i o r i t y he is a t t r ibu t ing to the dayl ighting strategy, and of the consequences associated with such a decis ion. In the case above, solar control should e i ther not be used in a design which emphasized dayl ight ing, or i t should be integrated in such a way that the day-l i g h t potential i s not reduced. An operable louver-system that changes i t s angle according to the sun and r e f l e c t s d i f fuse l i g h t into the space would be such a so lut ion. Spec i f ic recommendations can only be given in a wel l-def ined s i tuat ion and when the p r i o r i t i e s are eva luated. 7 7 In any case the f i n a l design requires reassessment of the tota l window system, since the effect of implementing a combination of strategies is d i f fe rent from that which can be predicted for each s ingly. 5.2.1. Exter ior : Consider Orientation Consideration of or ientat ion i s an important factor i n designing windows. The importance of or ientat ion has already been mentioned under the heading "Bui ld ing Form." The same pr inc ip les discussed:there apply to window design. Because of the. summer sun's higher and more northerly path across the sky, a south facing window gets no d i rect sun at sunrise or 78 sunset. At noon the sun intercepts the windows at a glancing angle. The projected window area is reduced and much of the l i g h t and heat i s re f lec ted . This high pos it ion of the summer sun permits l i t t l e - 171 -bui lding overhangs to t o t a l l y shade the window. The lower winter sun, however, is permitted to penetrate the window at a more d i rect angle and thus provide more solar rad iat ion. This i s i l l u s t r a t e d in Figure 5.36. Figure 5.36.: Sun Angles on South Facing Window By comparison an east or west facing window receives the summer sun for more hours of the day and at a more d i rec t angle than southern exposures. Therefore east and west windows are more d i f f i c u l t to shade. In winter, however, an east or west facing window receives the sun obl iquely and for less than half the number of hours the sun i s above the horizon. As a consequence windows should be smaller on the east and west facades. If windows are provided, the designer must be aware of the problems of excessive solar gains and shade the windows at the c r i t i c a l times. North facing windows receive no d i rect sun in the winter and only a short period during the day in summer. The influence of solar radiat ion 79 is not marked. Strategies to prevent heat loss dominate. WINTER , suis SUMMER SUN - 172 -5.2.2. Exter ior Accessories: Control Solar Gain Exter ior accessories are arch i tectura l elements that are used to reduce the solar radiat ion on a bui ld ing. The energy performance of the window system can be substant ia l ly improved with external accessories, as the cooling load of. o f f i c e a i r -condi t ioners i s reduced 80 by shading devices. The strategy of cont ro l l i ng solar gains through windows is pa r t i cu l a r l y e f f ec t i ve , since such heat gains represent 81 the major part of the cooling load. The basic p r inc ip le of solar control i s to intercept the sun's energy from entering the bui lding in summer and to l e t i t in during 82 periods when solar gain i s desired. The design of the solar control accessories must be based on the sunpath which changes both in a l t i tude and azimuth over time. The designer must determine with a heliodon or so lar shading masks, 'the amount of shading desired and at what times of the year and day i t is needed. With th i s information i t i s possible to design shading devices in optimum shape and s ize 84 for each or ientat ion. The shading devices would change according to t he i r or ientat ion and the d i f fe rent facades would not look a l i k e . Table 5.2. gives an overview of the exter ior accessories. It also i den t i f i e s b r i e f l y the main advantages and disadvantages. - 173 -Table 5.2.: Exter ior Accessories Advantage Disadvantage screens reduce^ s o l a r heat gain view and concurrent shading give$ daytime privacy reduces, d i r e c t & r e f l e c t e d glare reduce* s o l a r benefit i n winter reduce* daylight interference with outs wing window interference with window cleaning r o l l - b l i n d s easy and i n d i v i d u a l l y adjustable to reduce s o l a r heat gain when ...desired i n s u l a t i o n p o t e n t i a l at night impair d a y l i g h t i n g severely obstruct view maintenance required a r c h i t e c t u r a l projections: h o r i z o n t a l v e r t i c a l eggcrate intercept summer sun e f f e c t i v e l y on S, SW, SE - facade allow winter s o l a r gains allow view out possible s h e l t e r f o r facade can be used as access platform i n t e r c e p t sun e f f e c t i v e l y on east and west facades reduce^ glare provide wind s h e l t e r f o r facade p a r t i c u l a r y e f f e c t i v e on SE,SW -exposures during summer allow winter 3olar gain on S,SW,SE facades combine e f f e c t s of h o r i z o n t a l and v e r t i c a l devices can be used as balcony or loggia reduce daylight p o t e n t i a l l i t t l e e f f e c t on E and W - facades possible impediment i n summer f o r v e r t i c a l heat movement on facade c o l l e c t dust and d i r t reduce daylight p o t e n t i a l only p a r t i a l l y e f f e c t i v e i f f i x e d possible obstruction of view possible impediment to wind, cleanii reduce daylighting p o t e n t i a l sub-s t a n t i a l l y may lead to c e l l u l a r c a v i t i e s on facade and impair v e r t i c a l move-ment of a i r i n summer shutters reduce s o l a r heat gain on any , or i e n t a t i o n can be managed by users i n d i v i d . protection from r a i n and storm acts as an i n s u l a t o r at night reduce daylight p o t e n t i a l substan-t i a l l y and obstruct view high maintenance cost require* operable windows d i f f i c u l t to integrate i n t a l l builc awnings reduce s o l a r heat gain on any exposure protect window from r a i n removable i n winter reduces da y l i g h t i n g p o t e n t i a l high maintenance cost due to l i t t l e d u r a b i l i t y view p a r t i a l l y r e s t r i c t e d only f e a s i b l e on low p r o f i l e b u i l -dings ( p o t e n t i a l wind damage) - 174 -It i s obvious that most solar control devices reduce the dayl ight potent ia l . In such cases i t i s pa r t i cu l a r l y important to ensure that optimum benefit i s taken from the ava i lab le dayl ight, for instance by 85 l i g h t colours of the i n t e r i o r . Currently attempts are made to develop window systems that use solar control and provide dayl ighting simultaneously. Louvers, t i l t e d at a.variable angle, are very e f f i c i e n t in th i s respect.(see Figure 5 .27) . 8 6 87 Figure 5.37.: Solar Control and Daylight Penetration *.S 3 1.5 O 1.5 6m 45" 3 1.5 0 IS I I —I 1 1— 1 , 1 1 1 1 1 TRAPITIONAC SOLAR CONTROL REDUCES PA.yj.l6WT POTENTIAL NO SOLAR CONTROL. SOLA It CCWTROL AND BEAM DAY LI4.HTIN4 - 175 -5.2.3. Window Glass: Minimize Heat Loss, Minimize Solar Gain and  Provide Daylight The amount of window area, the or ientat ion and posit ioning of the window determine tb a large degree the heat losses and heat gains of a bui ld ing. Optimum Window Area The determination of the optimum window area, is a complex design problem. Most energy conservation manuals c a l l for a reduction of the window area because of i t s attendant problems of heat loss and Q Q on heat gains. ' Yet, the thermal ef fects of window area must be assessed in combination with other variables such as o r ientat ion , shading devices, glazing materials, and thermal resistance. Inter-actions among these variables have to be assessed for d i f fe rent window areas. In addit ion, and probably most important, the potential gains and.losses associated with the use of daylight must be evaluated. Whereas thermal performance might suggest an advantage in small windows, dayl ighting considerations make the optimum window area 90 91 s i g n i f i c an t l y larger. A detai led computer study by Kusada demonstrates that there is a range of window sizes occupying 25 to 50% of the window wall which can minimize yearly operating costs for an 92 93 c o f f i ce bui ld ing located in a climate s im i la r to Washington, D.C. ' ' " However, care should be taken when general iz ing from th i s re su l t . In Figure 5.38. the ef fects of the window area on the annual energy consumption for heating, cooling and l i gh t ing is i l l u s t r a t e d . The values given are based on a l a t i tude of 30 . - 176 -Figure 5.38.: Energy Consumption and Window Area "=150 '•• heating • cooling —heating and cooling 0.1 0.2 0.3 0.4 FRACTION O F G L A S S ON THE WALL Annual energy consumption for heating, cooling, and lighting per unit area of floor as a function of amount of window on the wall for a south facing room with surface to volume ratio of 1l: 0.33. The total energy consumption shows a well defined minimum when the window area is 25% of the wall area. The windows are shaded from direct sun from March through September. Several trade-offs occur in Figure 5.38. when the f ract ion of glass on the wall i s increased. At f i r s t the re l iance on a r t i f i c i a l l i gh t ing decreases sharply, and so does the tota l energy consumption. The l a t t e r reduction comes from a lowering of the cooling cost due to the reduction of internal heat generated by the a r t i f i c i a l l i g h t i ng . Further increase of the window area resu l t in an increase of the cooling and heating cost, and an attendant increase of the tota l energy consumption. The total energy consumption for a south facing room shows a well defined minimum when the window area i s 25% of the wall area. This result i s useful only in qua l i t a t i ve terms, since each par t i cu la r bui lding has to be assessed in i t s context. - 177 -Optimum Posit ioning Increasing window area does not necessari ly mean better day-l i gh t i ng . The posit ion of the window i s important in th is respect.. Generally i t i s most advantageous to posit ion a window as high as possible in the wall to ensure greater penetration. Glazed facad'e spandrels below the window s i l l do not contribute s i g n i f i c an t l y to the dayl ight in an o f f i c e . From an energy e f f i c i ency point of view 96 there is no need to design windows that reach from f l oo r to- f l oo r . However i t i s important to ensure that a view i s provided for o f f i ce workers in standing and s i t t i n g pos it ions, since a view i s an 97 98 integral element in a good working environment. ' Figure 5.39.: Posit ioning of the Window in the Wall CURTAIN - WALL PARTIALLY ALAZED ELEMENT - VJALU L . o : •SECTION ELEVATION - 178 -Selection of Glazing The select ion of the appropriate type of glass has a s i gn i f i c an t e f fect on the window performance. There are numerous technical manuals, manufacturers spec i f icat ions and standard ca lcu lat ion procedures that can 99 help the arch i tect in his decis ion. The appl icat ion of s ing le , double or t r i p l e glazing and the use of solar control glasses must be evaluated for each par t i cu la r case. However, some general pr inc ip les should be kept in mind. Orientation must be recognized as an important factor in deter-mining the type of glass. Situations should be analyzed i nd i v i dua l l y , to determine whether d i f fe rent glazing types should be used on d i f fe rent exposures. Currently, for instance, so lar control glass i s often used on a l l facades of an o f f i ce bu i ld ing , even i f there is l i t t l e need to protect the north exposure from solar rad iat ion. The se lect ion of the glazing type ef fects d i f fe rent window functions d i f f e ren t l y . The interplay of several factors must be considered. An example i s the use of solar control glasses. The se lect ive character i s t i c s of glass are used to control solar gain. A spec i f i c solar r e f l e c t i v e glass rejects 58% of the incident solar rad iat ion. Only 14% are. transmitted through the glass. This e f fec t i ve solar con t ro l , however, i s brought at the expense of the dayl ight penetration, which is reduced to a mere 40%. In th i s case dayl ighting cannot be used extensively and a r t i f i c i a l l i gh t ing has to compensate for the inadequate i l l uminat ion . But a r t i f i c i a l l i g h t i n g increases the cooling load and the shading e f fect of the r e f l e c t i v e glass is p a r t i a l l y o f f set i f tota l energy consumption is analyzed. - 179 -Figure 5.40.: Effect of Solar Control Glasses CLEAR 4LAS5 .SOLA* REFLECTIVE A LASS SOLAR ABSORBING A I. ASS .fcmw CLEAR FLOAT 4LASS 6 CLEAR ^LAS5 W'TH & mm ANTI SUN FLOAT SOLAR CONTROL FILM This indicates that the designer has to be aware of the consequences when select ing a spec i f i c type of glass and that he or she must cons istent ly fo l low a chosen idea. 5.2.4. _ Inter ior Accessories: Control Natural Light The e f fec t i ve regulation of natural l i g h t i s the p r inc ip le function of the i n t e r i o r accessories. Whereas solar rad iat ion i s contro l led most e f f e c t i ve l y outside the bu i ld ing, dayl ight i s regulated most conveniently at the inner side of the bui lding sk in. Inter ior accessories allow easy a c c e s s i b i l i t y and management as outside conditions change or as the user requirements of the i n te r i o r change. The strategy of cont ro l l ing natural l i gh t i s important in two aspects: F i r s t , the - 180 -i n te r i o r accessories can be used to control glare and d i rect sunlight f a l l i n g upon occupants. Second, devices such as r e f l e c t i v e bl inds can be used to project l i g h t into space, using the c e i l i n g and the walls as a d i f fuse r e f l e c t o r . ^ 5.2.5. Inter ior : Cap i ta l i ze Upon Daylight Potential and Upon  Select ive Treatment of Solar Gains Design strategies for the i n t e r i o r ensure that optimum benefit i s derived from the energy assets the window provides. In th i s context two areas are important: dayl ight and solar gains. Daylight The surface reflectances of the i n t e r i o r space determine to what degree the dayl ight potential provided by strategies at e a r l i e r plan-ning levels can be u t i l i z e d . An i n te r i o r with Tight colours on c e i l i n g , wa l l s , f l oo r and furn i ture and interspersed randomly with darker spots has a tremendous pos i t ive influence on the i l luminat ion 102 qual i ty of a space. It leads to considerable energy savings, since dayl ight i s adequate for more hours of the operation time. It has been estimated by Tamblyn that a change from dark i n t e r i o r colours to 2 bright ones can resu l t in a reduction, of power of 10 Watt per m (1 W a t t / f t 2 ) . 1 0 3 - 181 -Figure 5.41.: Inter ior Lighting TASK U4HTIN ANP AM8IENT 6£AM PAVLI^HTIN4 IN OFFICE. WITH HI4H SURFACE REFLECTANCES Solar Gains If solar gains are to be transmitted through the f a b r i c , a buffer zone has to be created between the bui lding skin and the occupied space, in which the solar gain can be trapped. The incoming energy then has to be d i s t r ibuted beyond the v i c i n i t y of the window, e i ther by mechanical a i r c i r cu l a t i on system or by natural heat convection. In th i s context the thermal mass of the bui lding has to be taken into .104 account. - 182 -Figure 5.42.: Buffer Zone and Solar Gains VIINTER SUMMER - 183 -5.3. Wall Design Strategies Walls are much less sens i t ive to heat gain or heat loss than windows, therefore, wall design is generally a secondary consideration. However, i f the wall area is large and therefore the window area smal l , wall design becomes more important. Wall design strategies deal with the fol lowing character i s t i c s of wal l s : 5.3.1. Insulation: Minimize Heat Loss 105 In cold climates heat loss through walls i s considerable. Insulation is t r a d i t i o n a l l y used to minimize th i s heat loss. Generally speaking th i s i s one of the cheapest and most e f fect i ve ways of energy conservation. The optimum insulat ion can be determined as 1 r\c presented in Figure 5.43. Figure 5.43.: Optimizing Insulation Thickness i). insu lat ion i i ) thermal capacity i i i ) colour and texture THERHAL RESISTANCE. - 184 -However, in buildings with high internal gains i t i s not always c lear whether the main problem i s one of heating or cool ing. Therefore, more insu lat ion is not always advisable as Spielvogel points out, since in some instances the concern might be to l e t excess heat d i ss ipate from the b u i l d i n g . ^ As the energy conservation strategies which aim at a reduction of the internal heat gains are implemented, the balance is sh i f ted towards heating, and insulat ion assumes more importance. The choice of i n t e r i o r or exter ior insu lat ion has an ef fect on the thermal performance of a bu i ld ing. Inter ior insulat ion excludes the wall elements with a high thermal capacity, such as br ick or concrete. Exter ior insu lat ion encloses the thermal mass of a structure with a continuous layer of in su lat ion. A consequence of using exter ior insu lat ion i s that the bui ld ing shel l i s not d i r e c t l y responsive to the heating plant. There i s a time delay before the internal surface temperature slowly r i ses a f ter the heating is turned on. In th i s context a further strategy can be outl ined that deals with thermal capacity. 5.3.2. Thermal Capacity: Increase Thermal Mass Walls with great thermal capacity (capabi l i ty to store heat) are c l a s s i f i e d heavyweight, whereas walls with l i t t l e thermal capacity are l ightweight. Heavyweight elements of a structure can be used to absorb heat gains from internal sources and. from trapped solar rad iat ion. Later, when the surrounding temperature i s colder than the wall temperature, the heat re-radiates into the space. The - 185 -greater the thermal capacity i s , the larger i s the time delay. This p r inc ip le can be used advantageously for passive so lar heating in o f f i c e buildings in w i n t e r . ^ 8 ' ^ Even more a t t rac t i ve is the use of the reverse p r i n c i p l e in summer. During summer nights r e l a t i v e l y cold outdoor a i r is vent i la ted (natural ly or mechanically) through a bui lding with a high thermal capacity in order to pre-cool the structure. During the day then, the structure i s capable of absorbing the excessive heat gains of the o f f i ce space. Figure 5.44.: Pre-Cooling of an Off ice S t r u c t u r e 1 1 0 THERMAL PERFORMANCE In order to take advantage of the opportunities for heat storage, the thermal capacity of the structure must be increased. This w i l l have a marked influence on o f f i ce bui lding design, because current design pract ice uses often l ightweight materials. - 186 -5.3.3. Exter ior Colour and Texture: Reduce Heat Gains The exter ior colour and texture of the bu i ld ing skin can be used to control solar r a d i a t i o n . ^ Heat gains experienced on dark 1 1 2 surfaces are as much as 50 Cabove ambient temperature. Light coloured surfaces r e f l e c t more l i g h t and heat than dark surfaces. For buildings with high internal gains i t i s most desirable to reduce solar gains during the summer. It becomes important to assess which surfaces are exposed to the sun at which times and what colour they have. On east and south oriented surfaces, l i g h t colours 113 are recommended to reduce the high solar gains. In the ear ly morning th i s heat on the east facade could be used to el iminate the 114 morning c h i l l . However, the continuous high so lar gains un t i l the early afternoon would resu l t in an overheating of the eastern oriented o f f i c e spaces during the warmest part of the day. In cases where the bu i ld ing ' s exter ior colour i s unfavourably determined by other than thermal considerations, the negative ef fects of so lar gain can be compensated for by a vent i lated facade construct ion, as i den t i f i ed in Figure 5.45. This e f fec t i ve wall design removes heat from the facade by natural a i r flow. In winter, 115 the cav i ty functions as a buffer zone and moderates heat losses. - 187 -Figure 5.45.: Venti lated and Insulated Facade Construction The fabr ic texture can be used in a manner s im i la r to colours to reduce heat gains in summer. Smooth surfaces tend to be more r e f l e c t i v e than rough surfaces and therefore support the character-i s t i c s of l i g h t coloured surfaces. So, l i g h t coloured smooth surfaces should be used on the south and east facades. - 188 -5.4. Roof Design Strategies Strategies for the. roof design are the same as those discussed under wall design.: However, d i f fe rent character i s t i c s become important, because the roof is a horizontal bui lding element. Since warm a i r i s r i s i n g , the winter heat losses through horizontal bui lding elements are more pronounced.than those through ve r t i ca l elements. In addit ion, the greatest solar gains in summer are experienced on horizontal surfaces. This indicates the importance of providing adequate insu lat ion on the roof in order to minimize heat losses and heat gains. Figure 5.46.: Measured Solar Radiation Data for Vancouver, Horizontal And Vert ica l Surfaces. It i s advantageous to select l i g h t colours that reject most of the incident solar radiat ion in summer. In winter, the sun angle is very Tow and horizontal surfaces receive l i t t l e solar energy that could be used to of f set the heat losses. Light colours are then advantageous because they minimize the radiat ing heat loss during - 189 -winter nights, whereas dark colours would increase the outgoing nighttime rad iat ion. The issues presented in th i s section have been directed at fabr design and energy e f f i c i ency . It has been emphasized that design decisions made at e a r l i e r planning levels can be cap i ta l i zed upon with an appropriate f ab r i c design. However, the arch i tect must be consistent in fol lowing a par t i cu la r idea through a l l planning level in order to ensure energy e f f i c iency and a good working environment. This approach requires a close co-operation between the arch i tects and engineers. - 190 -6. NOTES Notes to section 1. Introduction 1. Kurt Braendle, Sbren Christensen and Peter Renschler, Energiebewusstes Bauen (Stuttgart: Koch, 1979), P. 9. 2. Amos Rapoport, House, Form and Culture (Englewood C l i f f s : P rent ice -Ha l l , 1969). Notes to section 2. S i te 3. Ray J . Cole, "Energy Conservation Design F i l e , " AIBC-Forum, June 1979, p. 9. 4. ASHRAE, ASHRAE Handbook of Fundamentals 1972 (New York: American Society of Heating, Refr igerating and Air-Condit ioning Engineers, 1974). 5. The degree of var ia t ion d i f f e r s with each c l imat ic element. For instance, the sun path; is not s i t e s pec i f i c . The postion of the sun r e l a t i ve to the bui ld ing can be determined for a l l la t i tudes and times by the sun path diagram. Wind patterns, however, are strongly influenced by the immediate surroundings. Surrounding buildings can have such an ef fect on wind patterns that the condition on a spec i f i c s i t e i s very d i f fe rent from the data supplied by the nearest meteorological s ta t ion. 6. Ray J . Cole, "Energy Conservation Design F i l e , " AIBC-Forum, July 1979, p. 9. 7. Ib id . , p. 11. 8. F.W. Keith, "A Solar Heating and Cooling System for an Of f ice Building and Energy Conservation Program," Proceedings  of IEEE Annual Technical Conference in At lanta , Ga.,  20 Ap r i l 1978 (New York: IEEE, 1978), p. 4. 9. R.C. Basford, "Design Appl icat ion Using Solar Energy to Control Environment in a Major Off ice Bu i ld ing, " ASHRAE  Transactions 82 (February 1976), pp. .814-821. 10. John F. Ross, "Arct ic/Subarct ic Urban Housing: Response to the Northern Climates" (Master Arch. Thesis, Univers ity of B r i t i s h Columbia, 1977), p. 74. - 191 -11. Frank Bridgers, "Solar Energy Appl icat ion to Large Bui ld ings, " Energy Use Management, Proceedings of the International Conference in Tucson, Arizona, October 24-28 1977, vo l . 1 (Elmsford, NY: Pergamon Press, 1977), p. 329. 12. Ralph L. Knowles, Energy and Form (Cambridge, Mass.: MIT-Press, 1974). 13. Ralph L. Knowles, "Solar Energy, Bui ld ing, and the Law," Energy Conservation Through Building Design, ed. D. Watson. (New York: McGraw-Hill, 1979), pp. 230-244. 14. Ralph L. Knowles, "Solar Access and Urban Form," AIA-Journal, February 1980, p. 43. 15. Francesco N. Arumi, "Computer-Aided Energy Design for Bui ld ings, " Energy Conservation Through Building Design, ed. Donald Watson (New York: McGraw-Hill, 1979), p. 154. 16. Ralph L. Knowles, "Solar Access and Urban Form," AIA-Journal, February 1980, p. 47. 17. See also l a t e r section 4.5. Daylighting Design. 18. After Knowles, op. c i t . , p. 46. 19. American Inst i tute of Architects Research Corporation, Energy Conservation in Buildilng Design (Washington, D.C: AIA, 1974). 20. See Appendix B, "Sect ion" and " De t a i l " sheet. . 21. Ray J . Cole, op. c i t . , p. 13. 22. L isa Heschong, Thermal Delight in Architecture (Cambridge, Mass.: MIT-Press, 1979), p. 66. 23. This can be evaluated by various methods. The use of the heliodon allows the arch i tect to determine in a pract ica l way the influence of solar rad ia t ion. It can be analyzed which parts of a s i t e are shaded by surrounding bui ldings.at c r i t i c a l times or, on the other hand, how long the shadow cast of the proposed design w i l l be. Wind tunnels can be used to analyze the ef fect of wind in dense urban areas. The use of arch i tectura l models in wind tunnels i s pa r t i cu l a r l y valuable for large s ize projects in Central Business D i s t r i c t s , where wind flow patterns often cannot be predicted with reasonable accuracy on the basis of ex i st ing c l imat ic data. - 192 -Notes to Section 3. LAY-OUT 24. Kurt Braendle et a l t e r i , op. c i t . , p. 9. 25. An exception are sky l ights . However th i s appl icat ion i s l im i ted to low-r ise buildings with no more than two storeys, or to top f l oo r s . 26. Lay-out sketch a) i s the standard pract ice fo r h igh-r i se bui ld ings. The Bentall Centre developement i s such an example in Vancouver. Lay-out b) i s increasingly used, because i t offers the advantage of accommodating more than 4 prestigious corner o f f i ce s on a f l oo r . The o f f i c e bui lding at 1285 West Pender Street in Vancouver, designed by A. Erickson, is such an example. Lay-out c) i s typ ica l for o f f i c e developement in the 50's in Europe. The atrium lay-out d) i s now becoming more popular. 27. . -. , " A t r i a North Off ice Complex, Toronto," The Canadian Arch i tec t , February 1980, p. 18. 28. Roger T. Tamblyn, "Towards Zero Energy in Bui ldings, " speech held at the Conference "Energy, E f f i c iency and the Bottom L ine, " Vancouver, B.C., 25 October 1979. 29. Large glass areas, however, represent a s i gn i f i can t acoustical problem in o f f i ce s . Any sounds generated within the o f f i c e environment w i l l be ref lected to adjacent workstations. Good o f f i c e acoustics require the space to be very sound absorptive. For more information see D.A. P a o l e t t i , "Acoust ic, Impl icat ions of Passive Solar Building Design," in Proceedings  of the 4th National Passive Solar Conference, October 3, 4, 5 1979 in Kansas C i t y , Miss., vol 4. (Newark, Delaware: American Section of International Solar Energy Society, 1979), pp. 438-442. 30. See also Appendix B. 31. Tom L. Peyton, "Energy Management in Commercial Bui ld ings, " American Society of C i v i l Engineers.Issues Journal 103 (January 1977), pp. 31-35. 32. Braendle et a l t e r i , op. c i t . , p. 9. 33. Further re s t r i c t i on s are imposed by the National Building Code. 34. Fred S. Dubin and Chalmers G. Long, Energy Conservation Standards (New York: McGraw-Hill, 1978), p. 25. - 193 -35. Neil 0. Mil bank, "Energy Savings and Peak Power Reduction Through the U t i l i z a t i o n of Natural Ven t i l a t i on , " Energy and Buildings 1 (1977), pp. 85-88. 36. Royal Architectura l Inst i tute of Canada, ed., Energy Conservation Design Resource Handbook (Ottawa, RAIC, 1979). 37. This concept can be reversed in winter and of fers the potential for passive solar heating. Notes to Section 4. FORM 38. Compare e.g. the Crown L i f e Bu i ld ing, 1500 West Georgia: 24,200 m2 Pac i f i c Centre, new tower: 27,870 m2 Off ice Bui ld ing, 800 Burrard: 21,650 m2 see also: Greater Vancouver Regional D i s t r i c t , "Downtown Off ice Space," Quarterly Review (October 1979), p. 10. 39. Transmission includes conduction and rad ia t ion. However, heat losses by radiat ion are quite i n s i gn i f i can t and therefore not s p e c i f i c a l l y dealt with in th i s sect ion. 40. Dome-shaped bui lding forms would enclose even more volume with the same surface area as a cube. 41. This temperature corresponds to the 2.5% value of the average annual minimum temperature. 42. The maximum U,-value of 2.0 W/m2 C is assumed according to the table i n : W. Tao, "The ASHRAE Energy Standard for New Bui ldings: A Digest," Architectural Record, October 1976, p. 144. 43. Canada National Research Counci l , Associate Committee on the National Building Code, Measures for Energy  Conservation in New Buildings 1978 (Ottawa: NRCC, 1978), p. 17. 44. F r i t z Reuter, "Entwicklungstendenzen der Gebaeudetechnik im Bureauhausbau," Bauwelt 67 (Heft 14, 1976), p. 445, indicates ten storeys as the maximum bui lding height where natural vent i l a t ion is feas ib le . 45. Despite the above f igure by Reuter i t i s generally assumed that natural ven t i l a t i on i s r e s t r i c ted to buildings up to 4-6 storeys. 46. Lothar Rouvel, "Wir t schaft l iche Kombination von Anlagekomponenten fur die in tegr ie r te Energieversorgung von Gebauden", Elektrowaerme International 32 (March 1974), p. 79. - 194 -Dubin, op. c i t . , p. 154. K.J. L inton, "Case History: Energy Conservation," The Canadian  A rch i tect , March 1977, p. 46. ASHRAE, ASHRAE Handbook of Fundamentals 1972 (New York: ASHRAE, 1972). See National Bui lding Code 1977, supplement. Edward Mazria, The Passive Solar Energy Book (Emmaus, Pa.: Rondale Press, 1979), p. 11. Personal communication R.J. Cole. The comparison is based on solar data for the 21st of June in Vancouver. 80% fenestration and double glazing is assumed. Heat storage capacity is not taken into account. - . , "Rainbow's End," Progressive Arch i tecture, Apr i l 1980, pp. 98-105. Dubin, op. c i t . , p. 25. Province of B r i t i s h Columbia, op. c i t . , p. 17. However, heating space with the a r t i f i c i a l l i gh t i ng system is probably the most i n e f f i c i e n t use of energy, yet a report by Ross shows that in the Pac i f i c Northwest during 1974 l i gh t ing has been used extensively for heating purposes. This was only possible because e l e c t r i c i t y has been p len t i f u l and r e l a t i v e l y low in cost. Since then the s i tuat ion has changed dramatical ly. Ris ing:prices for energy requires a re-examination of the wasteful pract ice of the 70's. See Donald Ross, "O f f i ce Lighting and Energy Conservation," E l e c t r i c Consultant 91 (September 1975), p. 27. Richard G. Ste in, Architecture and Energy (Garden C i t y , N.Y.: Anchor/DoubTeday, 1978), p. 124. Calculat ions are based on values given by Gerhard Soel lner, "Beleuchtung, Klimatisierung und Energiehaushalt von Gebaeuden," Detail 4 (1976), pp. 465-471. Kunio Matsuura, "Turning-off Line in Perimeter Areas for Saving Lighting Energy in S ide-L i t O f f i ce s , " Energy and  Buildings 2 (1979), pp. 19-26. Stephen Selkowitz, " E f fec t i ve Lighting in Bui ld ings, " Lighting  Design and Appl icat ion (February 1979). - 195 -62. See also Appendix A. 63. Arthur Rosenfeld and Stephen Selkowitz, "Beam Dayl ighting: An A l ternat ive I l lumination Technique," Energy and  Buildings 1 (1977), pp. 43-50. 64. < v 7 : - ' \ } s . "Two New Energy Sources," Architectural Record, October. 1979, pp. 87-96. 65. Marguerite V i l l e c c o , "Strategies of Daylight Design," AIA-Journal , September 1979, p. 72. 66. R.N. Helms, I l lumination Engineering for Energy E f f i c i en t Luminous Environment (New York: P rent i ce -Ha l l , T980T 67. Scott Matthews and Peter Calthorpe, "Daylight as a Central Determinant of Design," AIA-Journal, September 1979, pp. 86-92. 68. Max H. Leu, "Wohnungsbau der Ant ike, " term paper, Swiss Federal Inst i tute of Technology, School of Arch i tecture, Zuerich, 1974, p. 58. 69. Matthews and Calthorpe, op. c i t . , p. 87. 70. Peter Calthorpe, "More than just Energy," Progressive Architecture, Ap r i l 1980, pp. 117-121. 71. , - - - ' , "Solar Nexus," Progressive Arch i tecture, Apr i l 1980, pp. 126-129. 72. See also: Canadian Wood Counci l , F i re Protective Design: Openings Through Floor Assemblies (At r iums] - ' (Ottawa: Canadian Wood Counci l , 1977), p. 1-7. Notes to Section 5. FABRIC 73. Ray J . Cole, op. c i t . , (January 1979), p. 18. 73b. John F. Ross, "Arct ic -Subarct ic Urban Housing," (Master Arch. Thesis, UBC, 1977), p. 146. 74. See also Chapter III: the development of windows. 75. Peter Manning, ed., Off ice Design: A Study of Environment, the Pi1kington Research Unit (Liverpool: Univers ity of L iverpool , 1965). 76. Ray. J . Cole, op. c i t . , (January 1980), p. 11. - 196 -77. Tamani Kusuda and Berlinda Lowenhaupt Co l l i n s , S impl i f ied Analysis of Thermal and Lighting Character i st ics  of Windows: Two Case Studies, .NBS Building Science Series 109 (Washington, D.C: Department of Commerce, 1978), p. 45. 78. Lyal l Addleson, Sunlight Geometry, Building Technology Notes (England: Brunei! Univers i ty, 1973). 79. S. Robert Hastings and Richard W. Crenshaw, Window Design Strategies to Conserve Energy, NBS Building Science Series 104 (Washington, D.C: Department of Commerce, 1977), p. 1-24. 80. Ernst Danz, Sun Protection (New York: Praeger, 1967). 81. See Figure 5.19.: Heat Gains in Off ice Buildings. 82. A. Olgyay and V ictor Olgyay, Solar Control and Shading Devices (Princeton, N.J.: Princeton Univers ity Press, 1957). 83. In a heliodon the posit ion of the sun can be simulated so as to determine shaded areas on the bui ld ing. Solar shading masks were developed by Olgyay in order to allow the designer to assess the effects of the sun and the shading devices. 84. For more detai led information see B. Ewing Walkley and John I. Y e l l o t t , "Energy Conservation Through the Use of Exter ior Shading, of Fenestration," ASHRAE . Transactions 82 (part I, 1976), pp. 703-733. 85. See section 5.2.5. Inter ior . 86. See also section 4.5.2. Window and Daylight. 87. David Baker, "Daylighting Design for a New State Of f ice Bui lding in San Jose, C a l i f o r n i a , " in Proceedings of the  4th National Passive Solar Conference, Oct. 3-5,  1979 in Kansas C i t y , vo l . 4 (Newark, Delaware: American Section of the International Solar Energy Society, 1979), p. 414. 88. J.K. Page, "The Optimization of Building Shape to Conserve Energy," Journal of Arch. Research 3 (September 1974), pp. 20-28. 89. General Services Administrat ion, Energy Conservation Design Guidelines for New Off ice Buildings (Washington, DTCl G.S.A., 1975). 90. See previous section 4.5. Daylighting Design. - 197 -91. Kusuda, op. c i t . , p. 45. 92. For a study case in Aust in, Texas i t was concluded that the optimum window area ranges from 10% to 40% of the wall area depending on various factors . See Francesco Arumi, "Day: Lighting as a Factor in Optimizing the Energy Performance of Bui ldings, " Energy and Buildings 1 (1977), pp. 175-182. 93. R.T. Tamblyn, op. c i t . , from Toronto indicated in his speech "Toward Zero Energy in Buildings" that 25% window area i s the optimum in many s i tuat ions . 94. Soel lner, op. c i t . , p. 467, concludes in his study that from a thermal point of view, su f f i c i en t insu lat ion values in cold climates can only be achieved i f the window area is not larger than 20% of the tota l wall area. However, he does not f u l l y recognize the benefits dayl ighting can provide. 95. Arumi, op. c i t . , p. 181. 96. F loo r - to - f l oo r windows are often used to express corporate image or "prest ige. " This is ref lected in the current market s i tuat ion. The value of o f f i c e space i s raised with increasing window area. As a consequence, developers presently f ind i t more economical to consider "prest ige" c r i t e r i a rather than energy e f f i c iency c r i t e r i a . Hence the large window areas on a l l facades of o f f i c e bui ldings. However glazed spandrels can be useful i f designed as a solar co l l e c to r . This p r inc ip le has been used in the competition, Appendix B. 97. Lawrence Wheeler, The Off ice Environment (New York: ISD Inc., 1969). 98. Ernest Wotton, "Some Considerations Af fect ing the Inclusion of Windows in Off ice Facades," Lighting Design and  Appl icat ion (February 1976), pp. 32^40. 99. ASHRAE Handbook, op. c i t . 100. After PiTkington Glass L td . , Toronto Company Spec i f icat ions. 101. See Figure 5.27. Beam Daylighting. 1 0 2 - - , "Qual ity Lighting with Fewer Watts," Architectura l Record, Mid - August 1975, p.113. 103. R.T. Tamblyn, op. c i t . (Conference). 104. See also fol lowing section 5.3.2. Thermal Capacity. - 198 -105. Kuhlmann attr ibutes 20% of the tota l heat loss to the heat loss of walls for an average o f f i c e bui ld ing. As mentioned e a r l i e r th i s f igure depends largely on the amount of windows in the wall area. See A. Kuhlmann, "Rat ione l le r Energieeinsatz-der Status Quo und Moeglichkeiten," Bauwelt 67 (Heft 47, 1976), pp. 1470-1473. 106. H.H. Swyter, "Vollwaermeschutz," Detai l 1 (no . l , 1975), p. 10. 107. "We have long been under the impression that some insu lat ion in buildings is good and that more is better. This generally holds true for res ident ia l bui ld ings, but is not necessari ly true for commercial, indust r ia l and i n s t i t u t i ona l bui ld ings. ...For buildings having internal or solar heat gains higher than 1 Watt per square foot, lower "U" values w i l l not necessari ly reduce energy consumption over the course of the year and w i l l usually increase energy consumption. Due to the wide d i ve r s i t y of bui lding types, internal gains, system types and operating condit ions, no rules of thumb can be used to establ ish "U" values that w i l l resu l t in minimum energy consumption." Lawrence G. Spielvogel, "More Insulation Can Increase Energy Consumption," ASHRAE Journal (January 1974), pp. 61-63. 108. Some examples are given in Research and Design, "Passive Technology," AIA-Research Corporation, Research and  Design 2 (January 1979), pp. 16-20. 109. However the arch i tect has to consider that the occupation time of the o f f i c e buildings para l le l s the hours of maximum solar rad ia t ion , and r e l a t i v e l y l i t t l e heat is required for operation during nights. Bridgers argues therefore that act ive systems are more economical, and the larger they are the more economical they become. See Frank Bridgers, "Solar Energy Appl ications to Large Bui ld ings, " Energy Use Management, Proceedings of the International Conference in '. Tucson, Arizona, 24-28 October 1977, volume 1 (New York: Pergamon, 1977), pp. 329-343. 110. See A l lan Temko, " C a l i f o r n i a ' s New Generation of Energy E f f i c i en t State Bui ld ings, " AIA-Journal, December 1977, pp. 50-56. 111. Loren W. Neubauer, "The Semi-Solar Low Cost House Saves Energy Through Environmental Or ientat ion, " IAHS Proceedings. International Symposium on Housing Problems 1976, 112. C.R. Crocker, Influence of Orientation on Exter ior Cladding, CBD 126 (Ottawa: NRC, 1970). - 199 -113. Theoret ica l ly , absorption coef f i c ient s of 0.1 can be achieved with white i"finishings. In pract ice, d i r t accumulation allows only 0.3 for white and 0.5 for l i g h t colours. See Dubin, op. c i t . , p. 177. 114. Gerhard Soel lner, op. c i t . , p. 470. 115. This p r inc ip le is commonly used for roof construction. See also Hellmuth Kanis, "Schutzschirme der Waermedaemmungzweite Schale ueber dem Gebaeude und vor die Wand," Detai l 1 (no. 1, 1975), pp. 11-14. 116. R.J. Cole, op. c i t . (January 1980), p. 15. CHAPTER VI: CONCLUSIONS - 201 -CHAPTER IV: CONCLUSIONS This thesis shows that arch i tectura l decisions have a considerable ef fect on the tota l energy use of the i ndus t r i a l i zed nations. What is more, is that the a r ch i t ec t ' s decisions establ i sh a pattern of energy consumption that is carr ied forward for decades. There i s a great necessity for architects to design o f f i ces in a way that they need less energy and provide a better environ-ment for working than i t i s the case today. Energy conservation i s an opportunity to achieve both. This thesis presents the conceptual framework for the i n -troduction of energy considerations into the design of o f f i c e b u i l -digns. However, substantial energy savings can be achieved when the energy e f f i c iency problem is viewed in a wider context. The ana-l y s i s of broad planning issues, such as energy consumption for trans-portat ion, shows the need to re-think settlement patterns and work -home re lat ionsh ips. Decentralized settlement patterns and mixed use developments in which a var iety of a c t i v i t i e s are combined together within a bui lding complex o f fe r a great potential in improving ener-gy e f f i c i ency . Within the indiv idual o f f i c e buildings substantial improve-ments in energy e f f i c iency can be made. Improvements can be achie-ved by energy management decisions in the personal and operational area, fo r instance in changing c lothing habits or minimizing the hours of operation of the technical support systems. - 202 -However th i s thesis focuses on the improvements of bui lding design from a designer 's point of view. Five basic energy conser-vation strategies are introduced and examined at the planning l e -vel of s i t e , lay-out, form and f ab r i c : i ) control internal heat gains i i ) control solar heat gains i i i ) minimize heat losses iv) optimize natural vent i l a t ion v) maximize dayl ight capab i l i t i e s of the bui lding The general object ive of strategies for energy e f f i c i e n t o f f i c e de-sign i s to improve bui lding design in a way that desired indoor space conditions are provided and maintained with a minimum amount of energy. This study shows that the strategies present the arch i tect with considerable scope for innovation rather than imposition. Con-servation strategies are appl icable in a l l planning stages. If de-sign decisions on one level are predetermined by r e s t r i c t i on s which are outside the influence of the designer, appropriate s t r a -tegies for energy conservation can be chosen at the fol lowing plan-ning levels to compensate for the omission at the higher l e ve l ( s ) . Different strategies can lead to good design solut ions. There i s more than one s ingle solut ion for each problem. However, the arch i tect must be aware of the consequences of his decisions. The factors causing the energy use in o f f i c e buildings are i n te r re -lated. Any design decisions in th i s complex system w i l l a f fec t the in ter re lat ionsh ip of the factors , which in turn lead to a d i f fe rent - 203 -de f i n i t i on of the design problem. /It i s essential for the designer to be consistent in his design approach. Once a par t i cu la r s t ra te -gy is adopted, i t s consequences have to be recognized and dealt with through a l l leve l s of design. Table 6.1. summarizes schematically the energy conservation strategies given in the second part of th i s thes is . It must be em-phasized that part icu lary the strategy to maximize dayl ighting is important, since increased dayl ighting reduces the problems associa-ted with internal heat gains. _^  ._ _ ; ,, .  It i s essential to consider the interplay between the bui lding design, the mechanical and e l e c t r i c a l system design, and the control system design. The area of mechanical and e l e c t r i c a l systems design bears con-siderable potential for further energy savings. Research has focused predominantely on the e f f i c iency improvements of the sub-systems and i t s parts alone. Now i t i s widely recognized that substantial impro-vements in energy e f f i c iency can be attained by understanding these sub-systems and how they are integrated in the bui ld ing design as a whole. Further studies in th i s f i e l d are essential to both arch i tects and engineers. The area of bui ld ing controls was only b r i e f l y discussed in th i s thesis. Further research is needed to determine which types and means of controls are best suited and to what extent par t i c ipat ion of the bui lding users should (and can) be integrated in th i s concept. Since i t i s people who use energy, i t i s probable that the education of - 204 -people to conserve energy is Ithe most successful way to improve over-a l l energy e f f i c i ency . Obviously ' c o s t ' i s an important factor in o f f i c e bui ld ing design. However, i t would be fallaceous to base a l l design decis ions, especia l ly those with respect to energy consumption, on the present market s i tua t ion . Some design decisions may appear 'uneconomical' i f viewed only from today's market s i t ua t i on , because tax and incentive schemes have relegated energy e f f i c iency to a r e l a t i v e l y low p r i o r i t y . However, energy costs w i l l continue to increase and w i l l eventually no longer be transferable to tenants and ult imately to the publ ic. Low operating cost and energy e f f i c iency w i l l be essent ia l . Further energy conservation measures previously considered not v iable w i l l become eco-nomical. In th i s respect less conventional methods, such as the use of a l ternat ive technologies and renewable enrgy sources w i l l gain in im-portance. Table 6.1.: Summary 205 o cr cQ < LL Lu sir < o ss-•z 5 _> s < Lis I-T i z -4 at fc j/S 2 ic 5 < z X fc 3 UJ Z o vfl C> 111 => p ^ I .1 2 3 < o UJ X z 3 5 ID O cr o K < - J « U < < UJ 3 °_ I s Lu 0_ 5 o LU-LL. LU ^ i i vB -1 0T z; V) LU V 0) i< L U C LU O L u X VST Z 5 cQ = — Q b j U J £ X 2. 2 X X 1 I 11 3 z < d 8 fll 1— O < o < 2T UJ UJ I-UJ </» KA O J 7Z O s -o £ «/ LU bU o m 3 s < * < o tJ LU O . u O O LU X < < z : Ui > 1— o v-T. O O < z : < < Ui O < •< NT °^ S m o ,<n 1-< LU <J"> LU o Ul Q-o. < a* m - 206 PART THREE: REFERENCE MATTER - 207 -BIBLIOGRAPHY 1. REFERENCE .MATERIAL CITED 2. SOURCES CONSULTED - 208 -1. REFERENCE MATERIAL CITED Addleson, L y a l l . Sunlight and Daylight. Building Technology Notes. • England: Brunei 1 Univers i ty, 1973. Alexander, Christopher; Ishikawa, S.; and S i l v e r s t e i n , M. A Pattern  Language: Towns - Buildings - Construction. New York: Ox-ford University Press, 1976. American Inst i tute of Architects Research Corporation. "Passive Technology." Research and Design 2 (January 1979), pp.l6-2o. . Energy Conservation in Building Design. Washington, D.C: AIA - Research Corporation, 1974. American Society of Heating, Refr igerat ing, and A i r - Conditioning En-gineers. ASHRAE Handbook of Fundamentals 1972. New York: ASHRAE, 1972. Architects Journal. Handbook of Fundamentals. London: Architects Journal. 1971. Architectural Record. "Two New Energy Sources." 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"Sonnerschutz und Moderne Bauphysik." In Planning and Construction in Conformity with the Climate. CIB-Symposium Vienna, 20-21 October 1976. "Vienna: Tech-n ica l Univers i ty, 1976. Wright, G and Achenback, P., ed. Energy Conservation in Bui ldings. New York: S c i e n t i f i c American Pub l icat ion, 1974. Y e l l o t t , John I. " U t i l i z a t i o n of Sun and Sky Radiation for Heating and Cooling of Bui ld ings. " ASHRAE Journal (December 1973), - 227 APPENDIX A: CLIMATIC ELEMENTS - 228 -APPENDIX A: CLIMATIC ELEMENTS Appendix A i s intended to give a short overview of the basic character i s t i c s of c l imat ic elements which af fect the energy consumption of o f f i c e bui ldings. I am greatly indebted to the author, Dr. Ray Cole, for the use of th i s text. It has been published in the AIBC-Forum, June 1979 and is part of an "Energy Conscious Design F i l e . " For further information on c l imat ic elements the reader is referred to the bibliography. - 229 -aibc forum june/1979 Dr. Ray Co le CLIMATIC ELEMENTS The main climatic elements affecting the energy consumpt ion of buildings: (0 solar radiation (ii) air temperture (iii) wind (iv) atmospher ic radiation (v) precipitation Solar Radiation Solar radiation always constitutes a heat gain to buildings and thereby leads to a reduced heating requirement during the winter and an increased cool ing requirement dur ing the summer. Solar radiation can be related quantitatively to: (i) The solar output of radiation which descr ibes the upper limit of available radiation. (ii) The earth/sun relationship which descr ibes the geometr ic and time variability of solar radiation. (iii) The state of the atmosphere which descr ibes the degree of attenuation by scattering and absorpt ion. These factors provide the broad framework for describing the incident solar radiation. The exposure of the various surfaces of the building envelope to the solar path exercises final control over the amount and distribution of solar radiation over the building. The amount of solar radiation received at the site is therefore dependent upon: (i) Latitude - the effect of latitude is two-fold. Firstly at higher latitudes the angle of incidence of the sun's rays is lower and consequently the intensity of solar radiation on a horizontal surface is lower. Secondly the path of the sun's rays through the atmosphere is longer and more energy is absorbed and scattered by atmospheric constituents. (Figure 2a). Figure 2a (ii) Altitude - intensity of solar radiation received o n the earth's surface increases with height above sea level because less is attenuated by the atmosphere. (Figure 2b). S O L A R ALT ITUDE ANGLE Figure 2b - 230 -(iii) Topography - in higher latitudes, the intensity of radiation received at a certain location is governed by the inclination of the surface and direction of the slope. (Figure 2c). Figure 2c The direct solar radiation beam is depleted as it passes through the atmosphere. A proportion of the scattered radiation reaches the earth's surface. This is of a diffuse nature and comes from the entire sky vault. The solar radiation incident upon the building envelope is therefore, in itself, characterized by three components : (i) Direct Solar Radiation -which is the remaining portion of the extra-terrestrial radiation after attenuation by the atmospheric constituents. This arrives as parallel beam, obeying the laws of solar geometry. (Figure 3). (ii) Diffuse Sky Solar Radiation -which results from scattering by the atmospher ic constituents. This arrives from the sky vault but is not uniformly distributed. (iii) Ground Reflected Solar Radiation - which results from solar radiation incident upon surrounding surfaces reflected Figure 3 onto the building surface. This is farily uniformly distributed. During cloudy condit ions the direct component is reduced. Whereas the total solar radiation remains reasonably constant for partially c loudy condit ions, during fully overcast condit ions the amount of total solar radiation is reduced. Under these conditions the directional characteristics of solar radiation diminish, i.e., similar amounts of solar energy fall on different building surfaces. The measurement of solar radiation requires relatively sophisticated instrumentation and recording equipment. It is therefore not a common ly observed parameter. Of those stations which measure solar radiation, the measurement is limited to the total' or global ' (i.e., Direct plus Diffuse Sky) solar radiation on a horizontal plane. Computat ion techniques exist which can separate this data into its direct and diffuse components and transform the horizontal data to that applicable to inclined surfaces. For stations where solar radiation is not measured, it is possible to use either the more common ly observed hours of bright sunshine or c loud cover in combinat ion with theoretical models of clear sky radiation to predict the incident solar radiation. - 231 -In response to recent interests in solar energy, university and research g roups have begun actively increasing the solar data bank. Air temperature A fter solar radiation, air temperature is the most important climatic element influencing the energy consumed in buildings. Temperature is primarily a function of incoming solar radiation. S ince incoming solar radiation is a function of latitude, temperature is also a funcation of latitude. If the earth were homogeneous there would be a relatively close correlation between temperature and latitude. However, air temperature is modified by several other factors such as altitude, presence of water and vegetation, wind, etc. The sky condit ion, whether it is clear or cloudy will influence the diurnal pattern - during clear sky condit ions the variation throughout the twenty-four hour period will be considerable and during overcast condit ions the temperature will be relatively stable. Air temperature is the most widely measured of all the climate elements and is generally recorded in a Stevenson Screen at a height of 1.1m above grass. The Degree-Days Value is primarily a meteorological statistic compi led from many years of observations of air temperatures at meteorolgical stations. The number of degree-days in the design heating season is calculated by taking the difference between the mean daily external air temperature and a predetermined internal base temperature and summing all the negative components over a specified period of time (i.e. if the external air temperature is above the base temperature this value is excluded from the summation.) One Degree-Day then, is a mean daily temperature of 1 °C below the specified base temperature. (Figure 4). T I M E HRS a. 5 >'-y-vy\'';'-:,;1' degree'" day.'--T I M E HRS 24 . 1 ^i^degree^ day 24 U T I M E HRS. THE C O N C E P T OF D E G R E E DAYS Figure 4 If a c o m m o n base temperature is used, the conventional degree-day total is simply a convenient way of descr ibing the severity of the climate from the heating engineers points of view. Similarly to other climatic parameters, the Degree-Days Value varies with location (latitude, proximity to coast, altitude, heat island effects, etc.) - 232 -Ml I Depending upon the geographical location of the site, there is a considerable distinction between the duration and severity of the heating season. The annual Degree-Day Value cannot distinguish between short, co ld, or longer, milder winters, and thereby gives no indication of the distribution of temperature variation over the time span embrac ing the degree-day total. Reference should be made to monthly degree-day totals. Atmospheric Radiation n the absence of an atmosphere the earth would be subject to temperatures in excess of 80°C during the day and -140°C during the night. Atmospher ic radiation originates from constituents within the atmosphere. The intensity of the radiation emitted at any wave-length is dependent upon the partial pressure of the constituents, their temperature and their thickness. Water vapour and carbon dioxide are the principle constituents with respect to atmospheric radiation, the former being by far the most important. As would be expected, c louds are powerful sources of atmospher ic radiation and will therefore always increase the amount of radiation relative to the clear sky condit ion. The prevention of the excessive outward radiation is termed the 'atmospheric green-house effect! The effect of atmospheric radiation is most pronounced in the case of horizontal surfaces exposed to an unobstructed sky vault. During clear sky condit ions the excessive outgoing radiation to the sky vault leads to a significant drop in the temperature of the surface below that of the air. This increases the internal/external temperature differential and thereby increases the heat loss. Precipitation General ly speaking, any cool ing of water-saturated air will result in some form of precipitation. The cool ing can be the result of vertical j ! air movement and changes in air j temperatures on a macro-scale, or i i caused by topographical characterist ics of the landscape. I It is extremely difficult to determine the cool ing effect of rain falling i against a building. However, in co ld | ' climate areas, a great deal of the winter precipitation occurs in the j I form of snow. S n o w significantly alters the reflectivity of the ground to i solar radiation (albedo], and thereby > \ increasing the amount of solar ; j radiation reflected upon inclined ! | building surfaces. I I Wind W ind has generally a ' cool ing effect on buildings. During the summer , wind induced , , ventilation can reduce j the need for mechanica l cool ing. | Dur ing the winter, wind leads to an ! , increased convective loss from I | building surfaces and an increased j | 1 infiltration. : j j Winds have a characteristic air ! < mass, that is they can be recognized as a coherent mass of a particular temperature and humidity. These temperature and humidity characteristics of an air mass are largely determined by the area from which it c o m e s and are modified en route by the areas over which it : passes. Air masses from continental • interiors will be less humid than those which have passed over oceans, air masses from the north will generally be colder than those from the south. Regions generally c o m e under the influence of many different air masses at different times of year. The macro or regional scale air masses are affected and modif ied by the underlying topography, giving rise to considerable local variation: (i) increase in wind velocity with altitude (ii) higher wind velocities on slopes facing wind - increasing with distance up the slope - 233 -(iii) funnelling of wind up valleys Wind speed varies with height above the ground. The variation depends upon the roughness of the surface and for the earth there are an infinite number of possibilities. To simplify the position, the earth can be divided into three types of surfaces: ' (i) flat open or sea (ii) rough wooded (iii) urban The height in which the variation takes place (the boundary layer) as well as the curve of variation differs from the three types of terrain. (Figure 5). Most measurements of wind made by the meteorolgical network are at a height of 10 m above the surface on airfields which are usually in areas of open country. The equivalent wind speed would occu r at a height of about 3 0 m in rough country nearby or about 5 0 m in the centre of a large urban development. It is important to appreciate this velocity gradient when interpreting wind data. At the edges of developed areas, the velocity profile is that appropriate to the type of land over which the wind has blown. It only becomes the velocity profile of, say, an urban centre after passing over a considerable distance of urban development. Apart from the prevailing wind condit ions, localized wind phenomena can also occur which either reinforce or oppose the regional condit ions. Urban centre Rough wooded Open country country or sea Figure 5 - 234 -APPENDIX B: COMPETITION FOR LOW ENERGY BUILDING DESIGN L.E.B.D.A. C o m p e t i t i o n In e a r l y 1979 t h e Government o f Canada, r e p r e s e n t e d by t h e M i n i s t e r o f e r g y , Mines and Resources and t h e M i n i s t e r o f P u b l i c Works, spon-s o r e d t h e Low Energy B u i l d i n g Design Award C o m p e t i t i o n . The f o l l o w i n g p r o j e c t i s the work o f t h e d e s i g n team G e r a r d Wagner, Howard R i c e - J o n e s , V i v i a n e Hotz and Max Leu. The j u r y awarded t h i s p r o j e c t a 'Honourable M e n t i o n 1 . 1 COMMONLY 80kwhArtfyr FOR LIGHTING passive measures active measures NIYIHIIE RITURIL LIGHT IHCHEISE «(tU»il I ]GMT CCURTYIRD INCREISES M'URIl LIGuTIHG "ITHOOT SACRIFICING tHE EFfi t tE*-C or »•£ CO-FIft tUlLDING PUHD1N6 HISS E1TERID* C'lOING NMN 116x1 SURFICEISNOU.LIGHT entreatrj SOIL,ROC«I RE-FLECTS 11G"T INTO BOWS HIRROSS PEVPENOICULIR IO Gll/Frj E1TERI0O N H L S IRE USED IS L IG"T REFLECTORS W6r 40w BEDuC ! ION OF ENERGY CDN-SUHfllON IT INCREASING HITURIL LIGHT.REDUCTION OF COOLING 1010 RT I ONE RING IRIIF 1CI11 LIGHT LEVELS NITURH LIGHT IS STIMULATING RT I IS FLUCTUITIONS THUS KEEPING THE MCUPINIS IN TOUCH NIIH THE NITURH ENVIRONMENT IRT IF ICIIL LIGHT CREIIES PSYCHOLOGICII INO PHTSIO-LOGIC1L TENSIONS RESULTING IN INCREISED IBSENlEEISH IND UNEISINFSS T© CREATE mm FyiMCT»^LLYinri WLATOli NINOrnJS E1TENO TO 11SHT COL CURE!) CF ll 1NG "Kit" IILONS CEILING TO ICI IS LIG«T REFLECTOR 2 ENERGY SOURCES limited oil,gas supply 3 WASTED ENERGY for excess comfort USE 0» RthFNIBLE EN'BG' • MTONOflEC'RIC 'ONER IND SOLI" ENERGY IRE BOTH CIEIN IND RENENIBLE • NELLS IRE USED f OR K I T -INS RT E H R I C T I N 6 HEII FRO" THE GRPUNDNITER IND COOt INS BT INTRODUCING O C E S 5 "€IT FRO" THE flulioiHG INTO T K GROUND-NITER > HOT SIORIGE I INK REDUCES ENERGY CONSUMPTION *I STORING SURPLVS ENERGY SUNINt Dl»l|«l FO> USE •I NIGHT IND IS CHIRGEO it THE K i t RUHR COTRES-IOR UNIT INO SOtlR Hil l • COLO NITER CHHLEO DURING HOURS Of 10* ENERGY COSIS IS USED DURING HOURS Of HIGH ENERBY COSTS 25 I SUHHER THE COVERED RUT OPEN PIRRING NEEDS NO HEIT1NG OR WENIILITIfM I HE TEHPERITUPf IS SET TO l« ICCEPIIBLE RIN6E • INDIVIDUAL 10JUST"FtT Ci RE HIDE BT CLOTHING THE CPURTTIRO •PROVIDES NITUaiL "l 1GHI THUS S U I N G ENf-HGY IND •GREIH' INCREISING THE ItJlLITT Of THE NORKING EHVIRONHENI 8Y PROVIDING INVITING GREENSPICE •IS HIRHEO RY SPUR KIT TRIPPEO >Y THE GLISS ROOF ME IT LOSS FRO" THE tUUOIH IND USED NIRH IIR •II ICIS IS I NODES* I ING ICWE INO II HINlHWES ENERGY C0NSUHPT10N •IS COOL DURING SUWHER i t NITURIL rtNllllIION 4 SEASONAL CHANGES OF CLIMATE passive measures active measures SOIIR PINELS SUPPLEHENT HEII IND PROVIDE DOMESTIC HOT NITER COHMONLY ?00KNH/N,2/YEIR USED L _ j ON CO\D SUNNf BITS SOUR PIMfLS PROVIDE MIRPLUS HEII IS Mono FOR CIOUJT OifS HEAT LOSS passive measures active measures ! 1 REDUCE NORTH TO I POINT USE NITVRIL GRIOE TO MINIMIZE RORTKIST IND HpRTHNESt EXPOSURE INSULTING EIRTH 5^-IRFIS «1TF> THE SIM NEC«*N|t*l REQUIREMENTS I 0»« I ID*' THUS NO R E K I T I I 6 NECESSIR' PUNP SURPLUS M?II TO COLDER IBEIS USING IK RELIIIWIY NIRH EIRTH IS J KIT SIM GUSi »00» JRIP5 SOUR HEII SOLID PIXELS MtSttCE HE IT LOSS BUHDING HEII LOSS HEITS COURT YMD ho CO cn HEAT GAIN passive measures active measures NO KIT 61 IN IGllNST BERI - 240 -

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