ABSTRACT
More and more energy-efficient buildings have been built since the late 1970's. Rapidly escalating fuel prices that resulted in high heating and cooling bills increased consumer demand for such buildings. Initially, home builders and energy researchers focused on improving the energy efficiency of new buildings, but great energy savings possible from retrofitting old homes were neglected. The U.S. Department of Energy addressed this earlier imbalance by requiring electric and gas utilities to offer energy conservation assistance to their residential customers.
