Windows

Windows can account for 10% to 25% of your heating bill. During the summer, sunny windows make your air conditioner work two to three times harder. If your home has single-pane windows, consider replacing them. New double-pane windows with high-performance glass are available on the market.

COLD-CLIMATE:

Install exterior or interior storm windows; storm windows can reduce your heat loss through the windows by 25% to 50%.
Repair and weatherize your current storm windows, if necessary.
Install tight-fitting, insulating window shades on windows that feel drafty after weatherizing.
Close your curtains and shades at night; open them during the day.
Keep windows on the south side of your house clean to maximize solar gain.

WARM-CLIMATE:

Install white window shades, drapes, or blinds to reflect heat away from the house.
Close curtains on south- and west- facing windows during the day.
Install awnings on south- and west - facing windows.
Apply sun-control or other reflective films on south-facing windows to reduce solar gain.

SHOPPING TIPS:

Remember, the lower the U-value, the better the insulation. In colder climates, a U-value of 0.35 or below is recommended.
Select windows with air leakage ratings of 0.3 cubic feet per minute or less.
In temperature climates with both heating and cooling seasons, select windows with both low U-values and low solar heat gain coefficiency (SHGC) to maximize energy benefits.
Look for the ENERGY STAR and EnergyGuide labels.