Windows/Doors

Thinking about replacing your current doors or windows to save energy dollars? That's probably not the right reason to make that investment. While the types of windows and doors you have can affect your energy bills, they have far less of an impact than having your home properly sealed and insulated.

Homeowners may notice the air leaks around doors and windows, the larger leaks near the attic and the foundation have a much bigger effect on a home's energy efficiency. During the winter months, heated air escapes through the leaks near the attic, creating a "chimney" effect that draws cold outside air into the home through leaks at the foundation level. Windows and doors are generally located in areas where the air pressure is more neutral.

Windows

Another reason windows may feel leaky is because glass has less insulating value than the materials used in building a wall, so the air feels colder in front of a window. That colder air is heavier, so it falls to the floor, creating a drafty feeling. Keeping curtains closed can reduce this effect.

One old-fashioned solution is using storm windows. In fact, adding a storm window to a single-pane glass window may cut your heat loss in half and is normally more cost-effective than using a triple-pane window.

Doors

As with windows, replacing a door for energy reasons has less of an impact than making sure your home is properly sealed and insulated. Proper weatherstripping will also help you block gaps that allow indoor air to escape and outdoor air to enter.

The best insulated doors are generally made of metal with a urethane, polystyrene or fiberglass core. Wood panel and hollow core wood doors tend to be less able to insulate. Sliding glass doors tend to have the greatest heat loss, with French doors slightly more efficient because they have a tighter fit. With any type of door, the most effective way to reduce heat loss is to add a storm door (not a screen door).

To learn more about the factors affecting window and door choices, visit the Web site of the National Fenestration Rating Council.