Many of California’s existing homes and businesses waste energy in preventable ways, such as through poorly insulated walls, air leaks in the building structure, inefficient heating and cooling systems, and outdated lighting technology. The California Air Resources Board, the agency responsible for implementing AB 32, stated in its scoping plan that “expanding and strengthening existing energy efficiency programs as well as building and appliance standards” are key elements of the overall strategy to reduce statewide greenhouse gas emissions.