UBC Theses and Dissertations
Dwelling densification and "greenness": Hong Kong’s high-density housing and resource conservation Wong, Kam Sing
Urban dwelling densities have profound implications on the form of built environment, which in turn incurs significant effects on the patterns of resource use associated with housing construction and operational needs. Hong Kong is a compact, industrialized city with housing at very high densities. This thesis proposes and tests the hypothesis that Hong Kong's housing represents a green model of residential development which is conducive to low per capita consumption. Reducing per capita consumption is a primary greening agenda, especially for industrialized regions. "Wastes" are also increasingly seen as resources. This thesis addresses three aspects of resource use: energy, water (including "wastewater"), and materials (including solid "waste"). Hong Kong's housing development is commonly in the form of estates which are characterized by large site area measured in hectares and towers of 30-40 storeys. The current densities are 2000- 4000 residents per hectare of net site area, plot ratio of 5 and above, 1-2 square metres of communal open space per resident, and 15-20 square metres of gross floor area per resident. In contrast, the corresponding densities of North American single-family dwelling are 50-100 residents per hectare of net site area, plot ratio of less than 1, about 100 square metres of private open space per resident, and 80-100 square metres of floor area per resident. The analysis offered in this thesis shows that Hong Kong's dwelling densification is conducive to efficient centralized systems such as mass transit, sea-water flushing, and inorganic waste segregation — which consequently lead to low per capita consumption of fossil fuels and potable water and high per capita recovery of domestic solid waste. On a building level, the attached, compact dwelling configuration also leads to low per capita energy and material use associated with housing construction. However, very high "building densities" entail physical/spatial constraints on a number of greening practices, such as harnessing of ambient wind for space cooling and on-site recovery of wastewater and organic waste. A direction towards high "occupancy density" in company with moderate "building density" should be considered as a greener housing alternative in long term.
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