According to the U.S. Green Buildings Council, existing buildings and new construction can impact our air quality, health, waste produced, and many other factors that affect our daily lives. For example, buildings account for 65 percent of our nation's electricity consumption. Therefore, incorporating green building features in new construction and in planned renovations will result in ongoing benefits to the environment.
Green building practices integrate efficient materials and appliances, water conservation measures, indoor air quality, and other strategies to create a structure that requires less input from natural resources. Certifications such as Energy Star, Leadership in Energy and Environmental Design (LEED), and others can verify that homes built following green practices use less water and energy than those built with standard practices.
If you're simply looking for ways to make your existing home more efficient, Energy Star offers many resources, including a Do-It-Yourself Guide to Home Sealing.