Lyle pointed out, the key forms of decentralization were not primarily mechanical, but spatial and organizational. In order for a green economy to do more with less, proximity and multifunctional design are crucial. As permaculturalist Bill Mollison (1990) argues, oftentimes the greatest increases in a systems efficiency can be obtained by a simple spatial reorganization of its components so that processes can do more than one thing at a time. In my previous book, I explored the role of ecological infill in creating more compact urban settlements that can clean water and air, cool and insulated buildings, and provide food, energy and even industrial feedstocks. I also looked at a negative example of how spatial organization affects efficiency: suburban sprawl. Suburbanization maximizes the consumption of virtually all materials. Not only does it create needless markets for otherwise superfluous consumer durables, building materials, automobiles and infrastructure. It also separates residences from workplaces, creating the need for otherwise needless transportation (with all its attendant pollution). This wasteful development helped generate massive economic growth after WWII, but today we are beginning to pay the externalized costs of such. It is beyond the scope of this thesis to explore the role of spatial design of the built-environmentit is a major subject in its own right. But some appreciation of the central role of spatial organization in postindustrial economic efficiency is essential to understand the appropriate patterns of production and consumption of building materials. It helps us understand why reuse is so important, why regional materials are so crucial, why local production is essential, and how we might begin to create local markets for green production.