In an era of U.S. energy abundance, the persistently high energy bills paid by low-income households is troubling. After decades of weatherization and bill-payment programs, low-income households still spend a higher percent of their income on electricity and gas bills than any other income group. Their energy burden is not declining, and it remains persistently high in particular geographies such as the South, rural America, and minority communities.

This paper reviews empirical data from evaluations of the influence of residential energy efficiency retrofits on indoor environmental quality conditions and self-reported thermal comfort and health. Data were extracted from 36 studies described in 44 papers plus two reports. Nearly all reviewed studies were performed in Europe or United States. Most studies evaluated retrofits of homes with low-income occupants. Indoor radon and formaldehyde concentrations tended to increase after retrofits that did not add whole-house mechanical ventilation.

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.