What is the urban heat island effect?
It sounds scary and it is. The effect is a warming of cities as a result of the pavement and roof surfaces that retain heat. This makes urban centres hotter than the rural areas around them, which in turn increases energy consumption to cool down the cities. This effect can also decrease air and water quality.
One way to mitigate the heat island effect is green roofs. These insulate the building, collect rainwater, absorb heat, and can also help clean the air.
In 2009, Toronto was the first city in North America to introduce a green roof bylaw. This bylaw requires that most new developments over a certain size must have a certain percentage of green roof space.
Tridel’s Innovation Manager Subhi Alsayed was recently on a Weather Network segment about green roofs in the city. The video, which can be seen below, features shots of Tridel’s Ventus and Republic buildings as well as the Deltera-built North Toronto Collegiate Institute. Subhi spoke about the challenges of building green roofs.
“We’re seeing higher and higher multi-unit residential buildings being built in the city of Toronto,” says Subhi. “Locating a vegetated green roof at those altitudes , when you’re talking about a 75 to 80 story building, has it’s own challenges. Wind uplift and wind pressure at that altitude is higher than wind pressure at a lower elevations.”
Learn more about green roofs in Toronto: