I Built A Passive House With Solar Panels On A Suburban Lot

In 2010, my wife, Phi, and I had been thinking about building a house, and we discovered that you could build one—even in a cold place like Toronto, where we live—that could be heated almost entirely by just the sun coming through the windows. It’s called a passive house—an ultra-energy efficient house with a low reliance on mechanical systems to heat and cool it. 

I saw it as a way to help the planet and save money—and, as an engineer, a technical challenge. So I started designing a house. But I’m not an architect, and I’d never designed a house before. I showed my design to a couple of architect acquaintances and a colleague. The first one told me, basically, it was a terrible design, but he was very polite about it. Another colleague spent about four hours telling me (in a nice way), “This whole thing sucks.” So I realized I needed to start over. I found a design by Marianne Cusato, an American architect, for her New Economy Home—a 1771-square foot, two-storey home that is designed for maximum efficiency and economy. I adapted the design to our needs, with two-foot-thick walls for energy efficiency, an elevator shaft to future-proof our house, a second stair and extra entrances.

We started building in 2012. I was already planning to put solar panels on the roof, but when we looked at the microFIT program in Ontario—a now-grandfathered program in Ontario that lets participants sell electricity generated by solar panels back to the Ontario Power Authority—it made even more sense.

We’ve been living in the house since 2014. The roof looks like that of a typical suburban house but with solar panels, with a single gable to maximize the area exposed to sunlight. Our solar panel system cost about $63,000 to install—it’s much cheaper to buy solar panels now, though—and it paid for itself in about six years because we were able to sell the electricity back at such a great rate. We’re lucky, because that buy-back program no longer exists. People who install solar panels in Ontario now get a credit toward their energy bill instead—with this program and the declining cost of solar panels, it would typically take around 10 years to recoup your investment now. 

Over the course of a year, we’re producing about as much solar energy as we consume. But pretty soon we're actually going to be producing more energy than we use by lowering our consumption even further, by switching to a heat pump for heating (we are currently using electric resistance). 

In Canada, the operation of buildings—including their heating and cooling—is responsible for 18 percent of our greenhouse gas emissions. Efficient buildings are a big way to reduce our footprint. But reducing emissions is also beneficial economically for a building’s owners and its inhabitants. 

Our whole house is electrically powered—we don’t need a natural gas hookup, which is one of the biggest sources of Canada’s greenhouse gas emissions. We spend about $2,500 a year on power—we don’t have a gas bill, because we don’t use it—and that covers heating, cooling, hot water, lighting, everything. 

In the winter, we get about two-thirds of the house’s heat just from the windows. The rest is from heated floors and a couple of radiators, heated by an electric water boiler. We probably use about a quarter of the energy a typical house would for heating. We have a ground source heat pump for cooling in the summer—it takes heat from inside and dumps it into the earth below the basement.

The windows are so energy efficient that they have condensation on the outside, not on the inside like in normal houses. There’s also a significant acoustic separation between the house and the outside and we happen to live in a slightly busy area. So, it’s very quiet in the house—in the summer there’s a bit of noise from the air conditioning, but in the winter there’s none. In the winter, the air inside isn’t dry, and our house is warm—on sunny days in the winter it can easily get up to 25, with no extra heating. We generally turn on our heating system in the fall, but about two months later than most other houses.

It’s fun to design a house, though there are some stressful parts. And we’re still a ways from paying it all off. Ten years later, my advice to anyone looking at a similar project would be not to get so excited about things that you lose sight of the bottom line. But when it comes to the solar and energy efficiency aspects of our house, we have no regrets. And it’s just so comfortable to live in, and we feel so secure—because even if the power went out, the house would stay warm.