Last Updated: May 17, 2021
Tracy Johnson and Kevin McKenny are an active, outdoorsy family. When she's not working as a director in healthcare information, and he's not working as a director of finance, they're biking, skiing, running, traveling, or otherwise exploring. When they decided to renovate an existing house in Toronto to retire in, they were equally adventurous.
Because they're both allergic to the toxicity inherent to many building materials, they needed to make conscious choices and make sure the home has good air quality. Moreover, says Johnson, "Power outages and ice storms over the past ten years, along with climate change, confirmed our desire to decrease our carbon footprint by building a sustainable house." In other words, the couple's goals, she adds, "were to renovate an existing house by recycling or repurposing as much of it as we could and build a healthy home—one without any high VOC-emitting products."
They researched net-zero and Passive House strategies, then realized they needed a consultant to guide them through their decision making. German Vaisman, an architect specializing in Passive House design, who was working at that time with Cool Earth Architecture Inc., not only designed their renovation but also took the couple to a Passive House conference, on a visit to a Passive House group in Minden, and three site visits to Passive Houses built between 2015 and 2017-18.
Johnson and McKenny decided to purchase a two-story, 1,200-square foot home built in 1941 in the Danforth area of Toronto and transform it into a Passive House. "We were drawn to the concept of building a net-zero house, and a Passive House seemed to be the best vehicle to do that, along with the healthiest end product to live in," Johnson says.
"The opportunity to build something different, with newer building technologies and more innovative systems and technologies, caught our attention," Johnson adds. The renovation added an ERV (energy recovery ventilator), a heat pump versus a furnace for heating and cooling, and planned solar panels for electricity to reduce their reliance on fossil fuels. The couple also realized, she says, that "The extra costs of building a Passive House did not seem out of reach."
Johnson, McKenny, and Vaisman decided to gut the existing structure's interior, retaining only its timber frame and brick veneer. They also increased the home's footprint by about 800 square feet, adding a modern extension for a living room and kitchen. The former kitchen is now the main entrance. They turned the old entry into the laundry room.
The roof, especially with the addition's extension, required additional insulation. The construction team also built a vented cavity on top of the existing roof to reduce thermal bridging. The construction team lowered the basement and cleaned out the asbestos. Because non-toxic materials were a priority, the house was insulated with dense-packed cellulose insulation. The cellulose was supplemented with Roxul/Rockwool (mineral wool insulation), Intello, Tescon Vana tape, and Aerobarrier air sealing.
The house now has an R-60 value in the walls and a higher R-value in the roof. Triple-pane windows and doors add to the home's sustainable strategies.
Despite the extension, the home qualified for EnerPHit certification. Airtightness tests were essential to obtaining the certification, says Austin Todd of CoEfficient Building Science, who the team hired to perform the tests. Lack of access to certain areas, like existing wall assemblies, and not wanting to disturb the exterior brick, Todd says, posed airtightness challenges. The Aerobarrier sealing did the trick "and got us to our goal," he adds.
The couple is proud of the fact that their renovated home uses zero fossil fuels. "We are on the grid and monitoring electricity costs for a heat pump, HRV, and heat pump hot water," Johnson says. "Back-up heat, should the electricity go out, is a Stûv fireplace." Solar panels are in the works.
One of the team's biggest challenges, says Johnson, was "finding tradespeople with experience in Passive House builds. When we sought out people without experience, we had to make sure they were willing to work differently and to change the way they work." During construction, integrating "the old house with the new extension posed some difficulties, as we had to ensure there weren't any thermal bridges," she adds. "Also, purchasing reasonably priced triple-pane windows in Canada was not possible within our budget."
The difficulties have been worth the rewards, however. The home is free from any "new house smell," Johnson says. The house is quiet. "Continuous ventilation with the use of Hepa filtration means our family's environmental allergies have lessened considerably, and we enjoy the comfort of even temperatures throughout the house in all seasons."
Since the family moved into the home in March 2020, right as the COVID-19 pandemic hit, they haven't yet hosted an open house for curious neighbors. "All of our younger friends and pedestrians who pass by are interested in what we've done," Johnson says. "The beauty and simplicity of our home impress visitors, although we don't yet have any direct converts to Passive House."
Johnson and Vaisman have, however, showcased the home and the Passive House building process at several Passive House Canada events. At these online events, Johnson not only talks about her interest in the Passive House building standard and how she worked through the phases of the project but also why she's thrilled to be living in her Passive House.
Camille LeFevre is an architecture and design writer based in the Twin Cities.