02/11/2026
On Monday, I was lucky enough to be able to assist award-winning builders and energy renovators, Bob and Kathe Tortorice with an energy audit at my client's house. My clients told me they were unable to keep their house warm enough when temperatures drop below 0, so I suggested they contact Building Alternatives, Inc. owned by Bob and Kathe. They came out on Monday for an energy audit, in which it was discovered that their house has an air-leakage rate of 9.12 ACH50.
How is this determined?
1. measure the volume of the home.
2. install the blower door in an exterior door (red contraption with fan).
3. prop open all interior doors.
4. turn on the blower door and get your readings.
The blower door measures how much air it can remove from the home at 50 pascals of pressure. 9.12 ACH50 means that, at 50 pascals of pressure, the fan would exchange 9.12 times the total air volume of the home per hour.
Modern code requires 5 ACH50 or lower, and 3 ACH50 is typically considered a high-performance home, and should be easily achievable with modern construction techniques. An ultra high-performance home (Passive House) would be required to have a rating of 0.6 ACH50.
All that to say, the home is leaky. While the blower door ran, we walked the home and identified several major leakage paths. This house is a hybrid timber/stick frame house, and wherever the large timbers met... well, anything, there was a major air leak. This could have been reduced with a properly detailed continuous exterior air barrier installed during original construction. A traditional interior air barrier wouldn't have been appropriate in this case because it would require hiding the timbers.
So what's the solution? Well, there are a few options. The most thorough solution would be to remove the exterior cladding (in this case wood clapboard and asphalt shingles), install a continuous air barrier all the way around the home, as well as continuous exterior insulation. I would recommend this IF the client already required new siding or roofing, but they don't*.
So the most reasonable first step is surprisingly simple: caulk all of the joints between the timbers and sheetrock. So that's what I'm doing, we're essentially creating an interior air seal that includes the timbers.
We also identified a couple of substantial air leaks in the form of: a chimney pe*******on through the ceiling (possibly the largest single leakage point), and a pluming access point in the upstairs bathroom. I've already spray foamed the chimney joint with a class 1 fire retardant spray foam. Next, I will install weather stripping onto the access hatch.
We will then have Building Alternatives back for another test, see how much the home has improved, and consider more remedies from there.
*If you’re ever re-roofing (particularly on vaulted ceilings) or re-siding, it’s worth considering continuous exterior insulation and air sealing details at that time
