This two-page fact sheet provides information on how the commercial and residential building sector are responsible for more CO2 emissions annually than those of any other country except China. Most of these emissions come from the combustion of fossil fuels to provide heating, cooling and lighting, and to power appliances and electrical equipment. This documents outlines tips on how the building sector can play a major role in reducing the threat of climate change by transforming the built environment to be more energy-efficient and climate-friendly.