With the high growth urbanization and increasing new urban population, the huge demand for infrastructures and dwellings has become a great challenge for the sustainable development in Chinese cities. The building sector shares one fourth of total energy consumption in the country and plays an important role in reducing the energy consumption and the consequential greenhouse gas (GHG) emissions. Some policies have been issued for promoting the low carbon sustainable development in China's buildings.

People spend most of their time inside buildings, and buildings are responsible for approximately one third of total direct and indirect energy-related worldwide carbon emissions. Likewise, buildings in the U.S. account for about 40% of total U.S. energy consumption. Future building development will be driven not only by emerging challenges such as vulnerability to a changing climate and resource scarcity, but also by disruptive innovations and societal changes.

The built environment accounts for approximately forty percent of the total energy consumption in developed countries. Because buildings have a long life, the greatest opportunity for energy reduction in the built environment will come from energy conservation in the existing building stock. An overview of the policy challenges presented by the built environment, with an emphasis on existing facilities, is accompanied by a discussion of specific technologies that may have the potential to reduce energy use.