would allow us to satisfy more basic human needs with far fewer resources. It would ostensibly also allow us to fit human economic activities within natural processes without disrupting them. But all this would entail fundamental changes in the form, content and driving forces of the economythe subject of Designing the Green Economy. Part and parcel of this dematerialization are the two other characteristics of authentic postindustrial development: detoxification and decentralization. Detoxification means the production and use of more benign materialsmaterials that are not only healthier, but that can also be cycled and recycled in closed loops, and eventually safely returned to nature as compost. Closed loop organization saves resources and thus helps dematerialize. Decentralization is a tendency of advanced economic development that we already see in energy technologiesfor example, the decline of the massive generation utilities like Ontario Hydro. Decentralization is also visible in more subtle ways in manufacturing processes; but more radical forms of it are necessary to establish tight loops of production and consumption, to make waste into a resource, and to make the most of regional materials. Decentralization is, however, also important because new forms of qualitative wealth based on service (and on the direct production for human need) must necessarily be community-based. Community participation is, in a sense, a technical necessity for achieving new levels of eco-efficiency. The purpose of this study is to look at the role of building materials in an ecological economy, and to consider the practical ways by which dematerialization might take placeand is taking placein the building industry. A related question is: what would a building industry based in servicethe key attribute of postindustrial green economylook like? This, of course, goes far beyond constructionsince it has major