Air sealing homes saves energy costs. This makes so much sense but it’s rarely done and it’s something we’ve only just begun doing to homes in order to meet certain Energy Star guidelines. Air sealing is very easy and it’s something that anyone with experience using a caulking gun can do.
If you look closely in the photos you’ll see white and yellow lines at the junction of all the framing lumber. The joint between the wall plates and the plywood, joints between adjacent studs and any joint that leads to the outside are all sealed with caulking.
If you stop and think about this concept it makes so much sense. We take the time to insulate the wall cavities but we typically ignore the small gaps between the wood members that lead directly to cold (or hot) air. This simple step shows up really well when you have a house tested for air infiltration with a blower door test.
The other place that needs to be sealed are holes made in the framing for wiring and plumbing. These holes should be filled anyway in order to meet fire codes but it also makes sense from an insulation point of view. The gap between window frames and framing member should also be filled with a low expansion foam.
Once the air sealing was finished this Energy Star home was insulated with spray-in-place cellulose insulation.