Any home will feel toasty when you've been spending some time outside in the chilly air. But once you've been inside for awhile—or perhaps when you get a look at your heating bill—you might realize that your home isn't preserving warmth as well as it should be.

No residence will be able to completely retain all of the heat produced by your furnace or other heating system. However, if you know where your home's inefficient areas are, you can take steps to seal more warm air inside during the winter.

Air leaks are one of the most obvious causes of heat loss. Landmark Home Warranty, a company based in Salt Lake City, Utah, estimates that 38 percent of heat lost from your home escapes through cracks or openings in your walls, windows, and doors. The Department of Energy says cutting down on drafts can save you about 10 to 20 percent on your heating costs.

An energy audit, which includes a blower door test, will depressurize your home and pinpoint the locations of any leaks. You can also conduct a more basic test on your own by shutting off any gas-burning appliances, shutting all doors and windows, turning on exhaust fans such as stove vents and the bathroom ventilation, and going through the home in search of leaks. An incense stick can be a useful aid, as disruption to the smoke will show that a leak is close by.

Any openings in the home are a potential site for heat loss, since they might not be properly sealed. These include door and window frames, vents, fans, exterior water faucets, cable and phone lines, and wall-mounted air conditioners. Leaks can also form if the weatherstripping or caulk around these gaps has started to break down.

Gaps or cracks can also appear in areas where building elements come together. Heat can easily escape through openings in the corners of the home, as well as baseboards and areas where the foundation and the siding meet.

Sealing these gaps is a fairly simple proposition. Landmark Home Warranty says you can install weatherstripping on the moving parts of your doors or windows, or replace weatherstripping that has worn out. Some gaps, such as those around a window frame, can be caulked to keep out cold air.

Electrical outlets and light switches are another surprising source of heat loss. Rachel Grier, writing for the Canadian company Crest Roofing, says foam gaskets can easily and inexpensively be installed behind plate covers to prevent cold air from entering the home.

Much of a home's heat loss occurs through the walls. Tobias Roberts, writing for the sustainable home improvement site Rise, says that since walls are in physical contact with colder exterior temperatures, heat can be lost through the conduction of heat to the outside.

Improving the insulation in the walls is one way to reduce heat loss, although this can be an expensive job. Landmark Home Warranty says basement walls can be a major source of heat loss, and preventing this condition may involve finishing the basement or adding insulation to the walls. Insulating walls in other parts of the home may involve making small openings in the wall to add blown-in insulation.

Windows and doors are another common source of heat loss. Roberts says most warm air is lost through gaps and cracks around the frames. However, window glass is also a poor insulator. Replacing the windows with more efficient ones, such as triple-glazed windows, can reduce heat loss but will also be very expensive. Grier says you can use window coverings, such as heavy drapes or temporary plastic sheeting, for a more affordable option.

Since heat rises, you'll likely lose some of it through the ceilings and roof. Heat can escape through cracks and holes or poor ventilation, and is also more likely to leave your home if it is poorly insulated. The Department of Energy says any attic hatchways located above a heated space should be insulated and have weatherstripping.

You should also seal any openings into the attic, such as those made by chimneys and ducts. However, vents in the attic should not be covered by insulation.