A home's total energy efficiency results from the combination of how it is used, how it is constructed and the efficiency of its energy-consuming systems. A well-insulated home with few air leaks requires less heating and cooling. This means smaller space-conditioning equipment can be installed, saving energy and space in the home.

Energy-efficient equipment is usually more expensive than standard systems, and finding energy-efficient equipment and locating contractors familiar with its installation may take some work. However, lower utility bills, greater comfort and eligibility for a higher mortgage make installation of highly efficient systems well worth the added time and money.

Talk with your utility or state energy office about recommended efficiency ratings for the systems you plan to install.