Braham, William2023-05-222023-05-222003-01-012008-08-15https://repository.upenn.edu/handle/20.500.14332/1716This paper examines the eco-systems model that underlies the LEED Green Building Rating System, comparing it to a number of other contemporary manifestations of the same model. As attendants at Greenbuild know well, the rating system offers credit for a number of well-recognized strategies that improve resource efficiency and indoor quality. Those strategies are based on an ecological model of the building and its occupants, which views them as agents in a dynamically interconnected system of flows and exchanges. between humans, their technological activities, and the biosphere. Or, in Sim van der Ryn's apt motto of ecological design: "form follows flow." (van der Ryn 2003)Working Paper