Unwanted air infiltration makes your home uncomfortable and increases utility bills. Caulk and seal cracks and holes that allow outside air to infiltrate into your home, or conditioned air to escape from it. Look for signs of air infiltration around walls, ceilings, doors, windows, recessed ceiling lights, plumbing penetrations, and electrical switches and outlets. Use non-expanding foam insulation around doors and windows.

Inspect single-pane and old windows. Boost their efficiency with weather-stripping or replace with energy-efficient models. Select new windows with a U-factor of .30 or lower and with low-emissivity (low-E) coatings. Window coatings save energy, especially on west-facing windows. For most residential applications, low-E coatings are sufficient. They can cut heat gain by up to 25 percent without changing a window’s appearance. Consult with an energy auditor before replacing windows.