Winter is the best time for wall insulation


When it’s cold outside, you may notice more drafts and cold spots in your home. That’s the bad news. The good news is that we can use thermal imaging to see exactly how that cold air is entering your home.


Thermal images show surface-heat variations, with higher temperatures appearing as lighter colors and lower temperatures or wet areas appearing as darker colors. During the heating season, cold air entering your home shows up with a dark purple color. We can easily see gaps in wall insulation or other air leaks because the cold outdoor air stands in stark contrast to the warm, light-colored air in your home.

Here’s an example of a home, where the wall insulation was not installed at the proper density, settling over time and allowing a steady stream of cold air to enter the home at the top of each wall cavity.

Find missing wall insulation with thermal imaging.jpg

Even if you’re not ready to insulate your walls or seal other air leaks, we recommend scheduling a free insulation estimate this winter. A GreenSavers consultant will use an infrared (IR) camera to look behind your walls and ceiling as well as around your windows and doors. Any air infiltration or areas of moisture will be easy to identify, and you’ll know exactly what you need to know when it’s time to take action.

It’s worth reflecting that we can do thermal imaging with an IR camera any time of year, but we tend to get the best results during the heating season (i.e. when it’s cold outside and warm inside). For an even better understanding of how much air is leaking into your home and exactly how much insulation and air sealing we recommend, it’s best to pair thermal imaging with a blower door test. We do both as part of our home energy audit.

Why is wall insulation so important?

Of all the upgrades you can make, adding wall insulation if you don’t have wall insulation already is the single upgrade that will have the biggest impact on the overall comfort of your home. Without wall insulation, your home is like a jacket that’s left open on a cold winter day. Your jacket does a better job of keeping you warm when it’s all zipped up. In the same way, your home does a better job keeping you warm when it has a continuous thermal boundary, i.e. when you have insulation in your walls, ceiling, and crawlspace.

As recommended by the U.S. Department of Energy, we insulate walls with dense-pack cellulose, which is made of 85% recycled paper fiber treated with a fire retardant. At the proper density, cellulose wall insulation does not settle over time and provides the added benefit of air sealing your walls. Learn more about the environmentally responsible insulation materials we choose.


We typically install wall insulation from the exterior, which does not have any impact on the appearance of your home. Our standard process: (1) Remove sections of siding. (2) Drill into the sheathing and dense pack each cavity to R-15. (3) Plug holes, reinstall siding, and touch up paint.

To sum up, if you have drafts or cold spots, winter is the best time to find out why. You can schedule a free insulation estimate with thermal imaging or a full energy audit, so when you’re ready to install insulation or seal air leaks, you’ll know exactly what you need to do. Wall insulation has a huge impact - In a home without wall insulation, about 35% of heat loss occurs through the wall cavities.

Bill Hoelzer