"Greening of housing areas in Sweden is often associated with the construction of new residential areas, such as eco-villages or urban districts with peak technology. If however, the environmental impacts of the whole sector is to be reduced, specific "greening strategies" for the existing built environment have to be developed (Svane, 1999). In Swedish eco-villages is co-operation among the residents necessary for the management of technical systems, e.g. heating or sewage. Co-operation is a part of the greening strategy and it is both a necessity and a goal which creates relations in the village that reminds of the sociologist Tönnies' concept "Gemeinschaft" (see e.g. Asplund, 1991). In two urban districts now under construction, "Hammarby Sjöstad" in Stockholm and "Bo01" in southern Sweden, the strategy is different. There, the ambition is to create green housing where Tönnies' idea of "Gesellschaft" relations between residents will suffice. Technical systems managed by professionals, for instance solar cells and local heating plants, will reduce environmental impacts without demanding co-operation among the residents. What, then could a greening strategy for existing multi-family housing look like? Is it a theme for co-operation among residents and with the manager, or is it rather a technical matter? The main purpose of my research project, "Environmental Practice and Robustness in the Small Neighbourhood", is to develop strategies that gradually decrease the environmental impact from existing Swedish housing. Several different kinds of measures could be include in such a strategy."