Developed by the Lawrence Berkeley National Laboratory, and sponsored by the U.S. Department of Energy (DOE) and the Environmental Protection Agency (EPA), this site is designed to help homeowners find the best ways to save energy. Users enter their zip code and they see the average annual energy costs for heating, cooling, hot water, etc., for a house in their area alongside the costs for an energy-efficient house. They then enter the characteristics of their home to get their estimated energy use.

To get down to specifics, the homeowner can enter details of their current heating/cooling system, ducts, thermostat, etc., and see how various changes will impact their energy bills.