The EPA says over 90% of the roofs in the United States are dark colored. A dark roof absorbs heat, leading to more need for cooling or air conditioning. The alternative is a "cool roof" — a roof that does two important things: it reflects solar energy, and it also radiates heat away after it is absorbed. The EPA has a list of cool roof products that will help keep your building's cooling costs under control. Of course, one other alternative is to use a "green roof", which is even better than a cool roof. Pictured here is San Jose's West Valley Library, which uses cool roof technology.