Such factors differ widely in character. They depend on a variety of complex, social phenomena and on options taken by numerous individuals and groups of people in times and places far distant from each other. As a result, from the perspective of a single citizen, they appear to be beyond the influence of individual choice. In many ways this perception is correct: the physical and social form of a city is something that the individual citizen can accept, not accept or even try to force, but which by himself he cannot change in the short term. It therefore constitutes his field of possibility in that given context. By this we mean the system of restraints and possibilities that decides what he can and cannot do; the sensible framework within which he may develop his objectives, and the array of opportunities on which he can base his strategies for achieving them. In so far as he attempts to enact sustainable modes of living, it also draws the limits within which he can direct his own behaviour and his own consumption choices.
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Unsustainable everyday life As it appears today, urban daily life implies an unsustainable environmental weight. On a first estimate we can say that this is true of every existing city, and every city imaginable up to now. This bitter observation is the point of departure for any other consideration on the subject. However, in the social learning process now underway, not all cities, not all urban forms are to be found at the same distance from the finish line. They are not all moving down the same track, some are demonstrating transformation dynamics that, to all intents and purposes, look negative; others are experimenting with activities and policies that may be promising. Let’s look at some examples. Cities with low population densities are intrinsically worse than those with a medium or high density, if only because of the differing demands for mobility they induce, or the differing technical, economic and environmental efficiency of each possible service idea. Contrary to pseudo-ecological cliché, on the whole it is easier to think of sustainable solutions in compact cities than in areas of less dense urbanisation. Ironically, Hong Kong could be a better starting point for sustainability than Los Angeles. The existence of certain infrastructures (separate garbage collection, gas supply networks, drainage water collection networks) makes ‘virtuous’ behaviour by citizens possible, which they would not be even with the best of intentions, if they were not present. It is useless to separate waste if it all ends up in the incinerator anyhow. Similarly, the existence of commercial activities and decentralised services tends to give vitality to a neighbourhood, while vitality starts to weaken when these services are concentrated in large suburban shopping malls. Pro-capita consumption is heavily affected by the reduced size of nuclear families: on average, one person living alone consumes more than double the amount he would consume if living in a family unit of four, at the same standard of well-being. The size of the family deeply affects the efficiency of a furnished, heated and air-conditioned domestic space, of the use of household appliances and the conservation and preparation of food. In conclusion, it is clear that the socially recognised (and so, not easily modifiable) standards of well being, strongly influence the general profile of consumption. For example, expectations for winter heating and summer air-conditioning are the result of a complex socio-cultural process. The outcome can be paradoxical, and dramatically negative in environmental terms (consider the polar temperatures in public buildings and shopping malls in many tropi64 ı SUSTAINABLE EVERYDAY