As colder weather approaches, homeowners feel a different kind of heat - high energy bills and costly repairs, often due to damage from moisture in the home.

Often the culprits are inefficient windows and doors that compromise the home's "envelope" - the fixtures and surfaces that together help regulate indoor temperatures and provide protection from the elements.

Any leak in the home's envelope hits the pocketbook hard and fast. Energy lost through windows alone can account for 10 percent to 25 percent of a household's heating bill, according to the U.S. Department of Energy.

"Now is the time to spend a little extra effort inspecting your home to make sure fixtures are in the best possible condition for combating cold, wet weather," said Joyce Richter, windows expert for Jeld-Wen, a window and door manufacturer. "Look for warping or cracks that indicate repairs or replacements are needed."

Jeld-Wen offers these additional tips:

* Use your senses to detect leaks. Hold a lighted candle near closed windows and doors. You'll see immediately if cold air is infiltrating indoors or warm air is seeping out. Feel for cold spots and look for condensation on cold surfaces. Inspect seals and weatherstrips.

* Take advantage of passive solar heating. Use insulated window coverings and close them at night. Open south-facing window coverings during the day.

* Understand how energy efficiency is measured. The most important energy efficiency rating is U-factor. This is the amount of heat flowing through a window. The lower the number, the more energy-efficient the window is.

* Consider Energy Star-qualified products. Appliances and other household products that have undergone rigorous testing will save money on energy bills during all seasons. The Environmental Protection Agency states that a typical household can save up to 30 percent on energy bills, about $400 per year, by selecting Energy Star-qualified products.

* Research the new generation of high-tech building materials. Composite materials, such as energy-efficient fiberglass doors, have become more widely available to homeowners. These materials protect against the forces of nature that cause the most worry: temperature changes, severe storms, moisture and insects.