Environmental impact

Green building practices aim to reduce the environmental impact of buildings. Buildings account for a large amount of land use, energy and water consumption, and air and atmosphere alteration. In the United States, more than 2,000,000 acres (8,100 km2) of open space, wildlife habitat, and wetlands are developed each year.

As of 2006, buildings used 40 percent of the total energy consumed in both the US and European Union. In the US, 54 percent of that percentage was consumed by residential buildings and 46 percent by commercial buildings. In 2002, buildings used approximately 68 percent of the total electricity consumed in the United States with 51 percent for residential use and 49 percent for commercial use. 38 percent of the total amount of carbon dioxide in the United States can be attributed to buildings, 21 percent from homes and 17.5 percent from commercial uses. Buildings account for 12.2 percent of the total amount of water consumed per day in the United States.

Considering these statistics, reducing the amount of natural resources buildings consume and the amount of pollution given off is seen as crucial for future sustainability, according to EPA.

The environmental impact of buildings is often underestimated, while the perceived costs of green buildings are overestimated. A recent survey by the World Business Council for Sustainable Development finds that green costs are overestimated by 300 percent, as key players in real estate and construction estimate the additional cost at 17 percent above conventional construction, more than triple the true average cost difference of about 5 percent.