Energy-efficient buildings, whether new or existing, lessen our nation's energy use.
Essential to Efficiency
Buildings consume 40 percent of all energy used in the United States and are responsible for nearly 40 percent of domestic carbon dioxide emissions. Efficient buildings reduce the speed and severity of global warming, lessen demand on the power grid, decrease stress on natural gas supplies, improve local air quality and save consumers money. Efficient features may be either embedded in new buildings or added to existing buildings through energy retrofits.
New Buildings
The design phase of a new building is the best opportunity to embed long-term energy savings into the building. Major improvements in building efficiency are often accomplished through stronger efficiency requirements in building codes. More on building codes.
Existing Buildings
With less than 1.5 percent of the U.S. building stock built new each year, improving existing buildings is critical to improving building efficiency overall. Energy retrofits, which upgrade equipment and seal the envelope of existing buildings, can save building inhabitants up to 20 percent on their utility bills. Still, participation in retrofit programs remains low. Financial support and technical assistance from all levels of government can help drive energy efficiency retrofits.

Dana C. Christensen is Associate Laboratory Director for Energy and Engineering Sciences Directorate at