The science behind Toronto’s potential condo failures

Toronto may be leading all cities in North America for building condos but its boom could soon turn to crisis.

CBC Toronto has produced an investigation into what it calls "throwaway condos" - in reference to the floor-to-ceiling glass windows, which may fail 15 to 25 years after they are built. Given Toronto's massive condo stock, that could equal a lot of failures.

In simple terms, the glass window doubles as the outer wall of each unit. While it may make the building look sleek and modern from the outside, what's going on inside is cause for concern - due mostly to Toronto's seasons and temperature changes.

The freeze-thaw cycle that occurs in Toronto (and other Canadian cities who are erecting similar buildings) will eventually cause the sealant in the windows to fail, resulting in more hot & cool air getting into each unit. Condo residents will then have to crank up the heat or air conditioning to keep pace, resulting in higher energy bills. (Check out this graphic that explains how the failure happens).

Its not just the higher energy bills that owners will be stuck with - "window-walls" cost a lot more to maintain than traditional building materials in the long run and these owners will be picking up a huge maintenance tab 20-25 years down the road, according to John Straube, a building science consultant and professor in the Department of Civil Engineering and School of Architecture at the University of Waterloo.

"We have a hard time," says Straube, "thinking five years when we buy a laptop, ten years when we buy a car. With these buildings — both the skin and the mechanical systems are going to have to be redone in a 25-year time frame. The concrete structure will be there a long time but in 20, 25 years time, we are going to see a lot of scaffolding on the outside of the buildings as we replace the glazing, sealants and the glass itself."

Vancouver has had its own issues with leaky condominiums given its weather but with Toronto taking the lead in condo building and cities with similar climates like Ottawa, Montreal, Halifax and Calgary following suit, condo dwellers can expect energy and maintenance costs to skyrocket, all for the sake of living in a building that has style over substance.