Keeping any city from becoming an urban jungle is a perpetual challenge. That's why I'm such a fan of green roofs. Far from being fig leaves for brutal, impersonal steel and concrete, they promise not only reductions in sewer overflow and air pollution but also maintenance of biodiversity and reduced energy costs (woot woot!), and so much more. Ottawa, Toronto, Vancouver, Port Coquitlam and others have green roof by-laws on the books so that they too can enjoy simultaneous beautification and cost savings. Right under our noses (and above our heads), the City of Toronto added 7,700 square meters of green roof in 2007.
photo: courtesy of the Vancouver Sun
Well, green roofs don't have to be strictly green. If they did, they wouldn't be nearly as effective in promoting biodiversity! And they'd quickly get boring too. Nick Kerchum's green roof is a veritable garden oasis. His neighbours appear to have caught the green bug as well.
Green roofs aren't the preserve of home builders. The Hugh Garner Housing Co-operative, a 31-year-old complex located in Toronto's St. Jamestown neighbourhood, had a leaky roof about ten years ago. Rather than simply fix the roof, the co-op decided to take the opportunity to build a green roof. The roof is not only beautiful, it helps foster a stronger sense of community among residents. It is a perfect venue for gardening, chatting or even just sitting and enjoying the sunshine. It features an evaporative cooling system, flat-plate solar collectors for natural water heating and photovolatic panels for greater sustainability.
The roof is now finished, so it is available for our viewing pleasure!
You can find out more on the roof's website (yes, the green roof has its own website) here.
Green roofs come in two types: intensive and extensive. Intensive green roofs are intense - they usually feature complex design, deeper growing mediums (which allow for greater diversity of plants) and lots of recreational space. They also feature a higher price tag because designing and building them requires more time, labour and materials. Extensive green roofs tend to be simpler in design, have shallower growing mediums (and the greenery therefore tends to be more homogeneous) and may or may not have lots of room for human beings. If you're a gardening buff or host rooftop parties on a frequent basis, intensive might be the way for you to go. If you're just looking to reap the sustainability benefits of a verdant roof, your best bet is an extensive one.
Here's a video of a green roof at a farm near Ridgetown, Ontario. You may want to turn your speakers down, as the wind creates quite the noise. I'm surprised that the cameraperson doesn't fall off at any point during the 1 minute and 16 seconds of video, since that roof must have a slope of at least 30 degrees!
Research and Written by Josh Patlik, Student of International Development & Political Science at the University of Toronto.