Open this magazine wide. Now picture a hole in the side of your house that’s just a little larger than the pages in your hands. Imagine the wind blowing through that hole.
The hole is real. If you were to combine all the cracks and crannies in a typical Canadian home, they’d add up to almost 1,400 square centimetres, roughly the size of 2.5 magazine pages. Combine the openings in all of Canada’s 12.9 million homes, and you’re looking at a hole 20 times larger than Parliament Hill.
Plugging that hole is the simplest way for Canada to save energy. Plugging the hole also saves money, creates jobs, cuts greenhouse-gas emissions and makes our homes more comfortable.
We also know how to fix the hole. Way back in 1977, we built a house so airtight and so well insulated that a hair dryer could have kept it warm through the winter – in Saskatchewan.
Yet despite the fact that buildings account for roughly one-third of our national energy consumption and the fact that we’re world leaders in smallbuilding energy-conservation technology, Canadians still haven’t plugged the hole. Most of our existing homes remain quite drafty, and most of our new homes fail to meet decades-old efficiency standards.
This year, however, more than a dozen high-performance homes will be completed in cities and towns across the country. These include homes built to the fast-growing Passive House standard, as well as net-zero homes designed to produce as much energy as they consume. This story is about the idea at the foundations of these homes – an idea that roamed the world for three decades before coming home like the prodigal son.
Builders have long known that heat claims the lion’s share of the energy consumed in Canadian homes: 57 percent of the total, compared with 24 percent for hot water, 13 percent for appliances and 5 percent for lighting. They’ve also known that heat escapes wherever air escapes, mostly under doors or around windows. But it wasn’t until the 1970s that builders became aware of just how much heat leaks through these gaps.