A whopping 1/3 of all energy lost form an uninsulated home escapes through the walls… so what is one to do? Luckily, if your house is a typical wood-framed house, you can probably insulate them (more on bricks later—a tougher challenge). If your house was built in the last ten years it probably already has wall insulation, although unfortunately we run across many recently built homes with poorly installed wall insulation—and sometimes missing insulation.
Most houses built in the last century were built with a cavity in the walls. This means that there is an external wall, an internal wall and a gap between them. If the gap in your wall cavity is about two inches deep or more you can fill that gap with insulation (as seen above) and watch your heating and cooling bills decline.
Why aren’t more people talking about wall insulation? Unfortunately, the answer is that insulating wall cavities is more difficult than insulating your attic…you can air-seal and get a lot of insulation into an attic easier than into a wall. Most companies and contractors focus on the message to insulate your attic because you get a lot of bang for your buck, but if you’ve already adequately insulated your attic and you’re looking for the next step in energy efficiency cavity wall insulation might be for you.
The insulation materials used and methods employed for installation will vary depending on the construction of your house. It is a little trickier than attic insulation because even if you have wall cavities, not all homes are suitable for insulating. This can be because of the condition of the walls, or because of moisture and ventilation issues. We recommend an assessment by a BPI-accredited contractor—using a blower door, infrared camera, and checking for combustion safety—to determine the need for and best approach to insulating your walls.
For an entertaining and informative tutorial on cavity wall insulation, check out our very own Frank LaSala on the ‘Bridge Street’ program in Syracuse.