You wouldn’t hit the slopes without your shell, right? Wearing a fleece down the hill just wouldn’t cut it. We like to think of homes the same way — you can’t just insulate your home, you have to seal it too. The insulation in your home, just like the fleece you wear, keeps the heat in. By air sealing you restrict air flow, just like a shell protects your body from the wind. Together, air sealing and insulation make the difference between a cozy home and a drafty one.

If you added up all the leaks, holes and gaps in a typical home’s envelope, it would be the equivalent of having a window open every day of the year!  (Source:


If your home feels drafty, you probably need to seal it up. Air sealing is designed to prevent unwanted air from flowing out of (or into) your home. This often occurs around windows, garage doors, recessed can lights, attics, and crawl spaces. By addressing air leakage, you also address comfort and indoor air quality issues that might be present in your home.

You can tackle air sealing on your own with a caulk gun and by adding weatherstripping. To make sure the job is done right, we recommend consulting a professional who can utilize different technologies to identify air leaks.

The illustration at right identifies the most common sources of air leakage found in the average home.


The simplest way to identify an air leak is by feeling for drafts in areas of your home that should be airtight. Have you noticed a whistling sound near your windows? Do ice dams form around your roof in the wintertime? Are there gaps at the bottom of your exterior doors? Can you feel drafts around the window or door frames? If you answered yes or I think so to any of these questions, you need to air seal.

To confirm your theories, get a home energy assessment and a certified building analyst will come to your home to use a blower door and infrared camera to identify air leaks. A blower door test de-pressurizes your home, creating an environment that makes air leaks easily identifiable. By using the infrared camera during the blower door test, building professionals can target the air leakage and measure the air infiltration rate of your home.


In some cases, a few cans of caulk and weatherstripping can do the trick. But for those of you in need of more thorough air sealing, look no further than CORE rebates.

CORE rebates: 25% of project cost up to $500
• Home Energy Assessment required
• Air infiltration levels must be measured by a blower door test before and after air sealing
• Your project must demonstrate at least a 10% air leakage reduction, as measured in CFM50 by a blower door test

Utility rebates may be available:
Aspen Electric | Holy Cross Energy | Black Hills Energy |  Glenwood Springs Electric | Xcel Energy