Proper insulation is only one part of creating an energy efficient home. To reduce your heating and cooling bills and help maintain your home’s internal air temperature, you also need to seal air leaks.

Even if the attic, walls, and plumbing in your home are well-insulated, if the areas surrounding fixtures, doors, and windows are not properly sealed from drafts your insulation will be less effective. Sealing off drafts and stopping air leaks can improve your home’s energy efficiency. Air sealing your home is not difficult and can be a worthwhile investment for any homeowner.

Air Sealing Basics

Drafts allow cold air into the home or warm air out, making the HVAC systems work harder to maintain the temperature of the inside air.

Areas of your home where you may need to improve air sealing include:

• Attic, particularly gaps in existing insulation
• Doors
• Electrical outlets
• Fireplaces and chimneys
• Interior wall and ceiling joints and joists
• Places where plumbing, ductwork and electrical enters the home from the outside
• Windows.

Sealing leaks in these areas can reduce your utility bills and make your home more comfortable. You can seal many air leaks with expanding spray-foam and other simple techniques.

You can check for air leaks yourself using a tool like a candle or leak detector. You can also hire a contractor to perform a home energy audit, which will give you a more precise idea of where you need to reduce leaks in your home.

Air Sealing Home Doors and Windows

Doors and windows are obvious areas to check for and stop air leaks.

Sealing off door and window leaks is fairly easy; adding weather stripping around the edges of doors and windows will reduce leaks. If your windows are drafty, installing a window insulation kit or hanging heavy drapes can reduce drafts. Double-paned windows also help reduce heat gain and loss, as will door sweeps and draft guards.

In addition to leaks around the edges of windows and doors, the framing that holds these items in the wall may also be poorly sealed. You can fix this by removing the sill and front trim, and then adding insulation inside the framing space. The trim can be reinstalled with caulking to further seal the window and door edges.

Air Duct Sealing

Leaky air ducts can also increase your energy costs. As air is forced through your ductwork, it can escape through small gaps or holes. In the average house, up to 20 percent of hot or cold air may be lost this way, according to the U.S. Department of Energy. Adding duct sealing or insulation can reduce heat loss and improve energy efficiency.

Sealing Electrical and Plumbing Entrances

The points where plumbing and electrical wires enter your home from the outside can also allow outside air into your home. Sealing around the run with spray foam can help reduce drafts and air leaks. You may also consider insulating cold water pipes in unheated areas to prevent freezing.