Up where the air is clear
Leslieville attic reno gives growing family a bigger, cleaner, greener home
Luke and Marianne Windisch are pretty typical Toronto homeowners. As young newlyweds in 2012, they purchased a drafty, 1920s-era, semi-detached home in Leslieville, renovated it enough to live in, and had a baby.
They began considering a bigger renovation with plans for baby No. 2.
That’s where typical ends, though, since Marianne is a professor of building science and mechanical engineering at the University of Toronto. She knows houses from the inside out. She especially knows when one isn’t working well — and how to fix it.
“We had no insulation, air was leaking in through windows and electrical outlets, and there was a lot of thermal discomfort,” Marianne says. “To make it more comfortable, you have to tighten up the (building) envelope but also supply mechanical ventilation to compensate.”
They hired Greening Homes, based in the city’s Junction Triangle, to fulfil their plans. “They understood more than anyone else what we wanted to do,” Marianne says.
The couple’s plan for extra space was to push into the attic. They wanted to maintain the twinned appearance with the next-door semi, including the roof profile, and that meant a return trip to the city’s committee of adjustment with new design plans when their neighbours decided to also add onto their top floor.
Initially, the Windisches had planned about $250,000 for the reno. But the project “dramatically increased in scope” when they got a buy in from their neighbours and were able to build greater ceiling height and floor space in the attic, Marianne says. Ultimately, they spent about $600,000 — which also included gutting the entire house, adding insulation to the walls, new windows,
floors, HVAC, two new baths (main floor powder and third floor master), redoing the electrical, ductwork, sound proofing, and getting rid of bulkheads. The kitchen and secondfloor bathroom were put back as they were.
“We figured we were only going to do this once, so do it properly,” she says of the sevenmonth project completed in December 2017. The family lived in a nearby rental while the work was carried out.
“Yes, it’s more than we originally anticipated but basically, we have a brand new house.
“We love it. There’s lots of room — love the ceiling height, the sunlight that floods the space in the afternoon. The cross-ventilation is excellent, and it’s much healthier to live in. We get way less smoke from next door, and it’s less drafty.”
A drainwater recovery system will be an easy retrofit down the road, Marianne says.
Their new space added 600 square feet to their home, giving them 1,800-sq.-ft. and a voluminous third-floor master bedroom with 14-foot ceilings and ensuite bathroom, and a light-filled home office for Luke, the general manager for a medical device company. The second floor, with its two bedrooms and adjoining bath, is for the children: Anneka now 3 1/2 and the baby due in a couple of weeks.
With a slightly higher peaked front roofline and a flat roof extending over the back, the increased heat-island effect — more surface to catch sunlight — was alleviated by packing the flat roof with Roxul Comfort-board (for an R-value of 45), installing vents and a reflective coating.
Creating the high-performance envelope for energy efficiency and comfort was a challenge. With just 12 inches between them and neighbours to the south, and a party wall on the north, it meant gutting the house to insulate wall cavities from the inside.
Depending on the wall system, the walls were packed with either Roxul (spun mineral wool) insulation or blown cellulose, says Christopher Phillips, president of Greening Homes’, who has a master’s degree in building science.
Phillips also notes the Windisches saved approximately 4,000 kg of carbon dioxide in their insulation choices. “The big savings is choosing not to use spray foam. It’s literally the worst – the data shows you’ve used so much carbon to pro- duce the foam in order to save so little. Blown cellulose, which is chopped newsprint, is recycled and renewable, and the best thing you can use to go to less impactful carbon environment.”
Building code updates have made houses increasingly more energy efficient, he says. “This is all good, because the more airtight the less reliant we are on fossils to heat and cool. The downside is tight envelopes don’t present opportunity for good ventilation so you have to create it.”
They opted for a separate HVAC system on the third storey that allows greater control over the air on just the top floor without having to heat or cool the whole house.
Another part of the solution was to install a heat recovery ventilator that adds or removes heat from the house’s exhaust air. For instance, in winter the HRV returns cooler air which sinks to the floor where the top-storey return is located and the fresh air is picked up by the central air handling unit and redistributed to the rest of the house.
As well, clerestory windows atop the third-storey walls draw in natural light. They have a motorized open/close system and the stack effect — rising hot air that goes out windows — provides natural ventilation. On hot, humid summer days, they run air-conditioning just for the third floor.