The connotations and eco-efficiency of urban residential district

The current construction and usage of residential districts have consumed plenty of resources and energy and brought a significant amount of pressure to the ecological environment. This paper treats a residential district as an artificial ecosystem. First, the content of a residential district is discussed; then the concept of eco-efficiency applies to residential district and the original meaning of eco-efficiency is expanded. It is pointed out in this paper that residential district eco-efficiency do not only consider the economic value under unit environmental impact, but also consider the social value. The sustainable development of residential districts should rely on the relationship among natural subsystem, economic subsystem, and social subsystem.