U.S. Department of Energy - Energy Efficiency and Renewable Energy
Energy 101: Cool Roofs (Video)
Traditional dark-colored roofing materials absorb a great deal of sunlight, which in turn transfers heat to a building. Cool roofs use light-colored, highly reflective materials to regulate building temperatures without increasing electricity demand, resulting in energy savings up to 10%–15%. Cool roofs can also reduce the "heat island" effect in cities and suburbs along with associated smog and carbon emissions.
Also featured in this video are green roofs, which grow vegetation on top of a building to provide several benefits, including reduced energy use, reduced air pollution and greenhouse gas emissions, and enhanced water quality.
For more information on building technologies from the Office of Energy Efficiency and Renewable Energy, visit the Building Technologies Office website.