The first step in tightening up your home is finding the air leaks that need to be sealed. Why? A 1/16th-inch unsealed crack around a window can let in as much cold air as leaving the window open three inches!
The chart at right shows the primary places outside air infiltrates your home. Most are easy to fix with some inexpensive weatherizing materials:
If you’re not sure where to start, try Alliant Energy’s My Home Comfort Check Up energy audit - this free analysis will help you pinpoint energy wasters and learn how to improve your home's efficiency. You can choose the options that fit your needs and your lifestyle.
Measuring existing insulation
Before you head to the home store or call a contractor, you’ll need to measure the amount of existing insulation. To find out, you'll need a flashlight, a ruler, a screwdriver and maybe a ladder.
Blower door tests
If you’re not sure where to start weatherizing, a blower door test - performed by a certified energy auditor - can be a great investment in tightening up your home.
All windows and doors are closed, and a variable-speed fan is installed in the front door with a special air-tight seal. As the fan is turned on, the energy auditor will monitor the flow of air through the fan, as well as the air pressure inside your home.
Because your home is sealed and evenly pressurized, it’s easy to find out exactly where air leaks are occurring. While you’d probably expect to find drafts around windows and doors, you might be surprised to learn how much air can leak around electrical outlets and plumbing pipes.
A blower door test will cost around $200-$500, depending on the size of your home. If you follow the advice you receive for weatherizing, you could recoup the cost of the test in energy savings in as little as two years.