Our Important First Steps: Air Sealing and Insulation
By Marwan Daar
We moved into the Pocket a couple years ago and noticed that our home struggled mightily to stay warm during winter. On particularly cold days, the temperature would not be able to get above 17-18 degrees C despite the furnace running non-stop. We also discovered some particularly bad drafts on the main floor. Our gas bills during these months were horrendous (around $500/month). In early 2023, we decided to take action. We figured that air sealing would provide a good amount of improvement for relatively little cost and invasiveness. We learned about the Canada Greener Homes Grant and went to work getting a pre-retrofit energy assessment.
Our energy advisor (who now works at Goldfinch Energy) was shocked at how drafty our house was. The readings from the fan blower test were literally off the chart. The biggest offender was an incorrectly installed range hood in the kitchen. Using some creativity, we were able to put together a makeshift seal on the range hood and perform another test a week or two later. This time, the blower door test provided interpretable readings. The results still showed an air exchange rate of over 15 air changes per hour (at 50 pascals), which is quite high!
Based on other measurements and modeling, our total annual energy consumption was estimated at 196 GJ/year
Our first order of business was to properly fix the range hood, beyond the quick fix we had done. The contractor we hired discovered some very poorly installed ductwork and a poorly sealed vent on the outside of the house. After addressing this, we moved onto air sealing. After unsuccessful attempts to find a someone to do this, we contacted Paul Dowsett (the Pocket Change Retrofit Coach) for advice. He put us in touch with Goldfinch Energy, who in turn recommended the team at Core Contracting Group, with whom we went ahead in December 2023. The CORE team was great and did an efficient job (they use a door blower to help detect the drafts). They also advised us that we should add insulation to the exterior walls, as we had virtually zero insulation. This would not only improve the thermal insulation of the home, but would also reduce air leakage, as the physical material used to insulate would limit air flow. And given our balloon framing, the airflow was already very unrestricted to begin with.
They recommended dense-pack cellulose as an effective solution with minimal invasiveness (you create holes in the walls and pump the cellulose into the cavities). Given that our home was built with balloon framing, there was also a fair amount of work needed to seal off various cavities. After learning that the Canada Greener Homes grant would likely cover a substantial portion of the involved costs, we decided to go ahead with the recommendations, which were implemented in April 2024. In addition to the exterior walls, some other insulation was done (including a ceiling and topping off the insulation in the attic).
Given that the air sealing was done in December 2023 and the exterior wall insulation in April 2024, we had 3-4 months to experience the benefits of air sealing vs the benefits of air sealing + insulation. The air sealing made a marked difference, but the insulation was a real gamechanger. April was early enough in the year that we still had days below 5 degrees. The warmth was now more even throughout the entire home, even in our bedroom on the second floor, which previously got very cold due to the three exterior walls (and a ceiling right below the flat portion of the roof). The home also seems to retain its heat for much longer without the furnace having to run full time. Moreover, the insulation has dramatically improved our summer experience. That same bedroom upstairs is now much cooler, which has improved our sleep!
Our post retrofit audit showed a very good improvement, both on air exchanges (which is now about 2.5 times less), and energy usage (estimated to be about half of what it was).
The air sealing cost around $900 and the insulation (including all the prep work and plastering) was about $12,000 (these figures include tax). Our energy advisor has estimated that we may get up to a $9,000 rebate, which is very welcome news! We’re keen to see how well our home holds up next winter and are expecting our energy bills to be saner. And now that our home is well insulated, we can start thinking about using heat pump technology, which has the dual benefit of using electricity rather than gas, and of being able to produce more energy (in the form of heat) than it consumes from the grid, thanks to the thermodynamic wonders of the refrigeration cycle!
Our plan moving forward involves educating ourselves about heat pump technology and how it can be used to replace a gas furnace and/or gas boiler, as well as looking into the various loan options out there (e.g. Canada Greener Home Loan, or the Home Energy Loan Program) and any upcoming grant programs. When we’re ready to move forward, we plan to hire someone to help us select an optimal solution and help us implement it.
