Toronto First North American City to Require Green Roofs

Toronto is making history. The first city in North American to require green roofs on new developments moves into the third phase of its Green Roof Bylaw on April 30, 2012.

Adopted in 2009, the bylaw required the environmentally friendly roofs on residential, commercial and institutional buildings starting in 2010. Now, with the addition of industrial developments, all new buildings with a minimum Gross Floor Area of 2,000 square meters will be required to devote 20-60 percent of Available Roof Space to vegetation.

Aside from the pollution-scrubbing gift of rooftop parks, the greenery pays off in lower utility bills.  Two American green roofs give an idea of potential savings. The Chicago City Hall installed a green roof in 2000 and now saves $5,000 a year. New York’s Con Edison Green Roof absorbs 30 percent of the rainwater that falls on it. It also reduces heat loss by 34 percent in winter and heat gain by 84 percent in summer.

Thanks to the bylaw, Torontonians have access to an urban oasis on City Hall’s podium roof. They can check out the gardens atop the YMCA of Greater Toronto. If they buy a unit in the Hugh Garner Housing Co-operative, they can enjoy the largest green roof in Canada. They can also visit other green roofs, such as those on ESRI Canada, Duca Financial Services, and Ryerson and York Universities.

Other cities considering green roof bylaws will find a lot of helpful resources on Toronto’s website. These include policy development, benefits of green roofs, bylaw language, and construction standards.

Developers have not all embraced the new bylaw, citing increased costs. However, the marketing pluses of a green roof like the one at the Toronto City Hall, coupled with utilities savings and environmental pluses, is gradually gaining converts.

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Photo of ESRI Canada's green roof from emmlalala via Flickr Creative Commons


Carole H.
Carole H6 years ago

the greener the better - great - thanks

Amber Beasley
Amber Beasley6 years ago

awesome! I wish that were required EVERYWHERE!

Sam Kroll
Samantha Kroll7 years ago

This is awesome! I hope we see this in the US soon, it would be so amazing for the enviorment, economy, even those without food if they grew food plants!

Arild Warud

This is great,thanks Toronto.

Tami C.
Tami Co7 years ago

So nice of them to take such great care of their own envrionment, yet, have no problems running a pipeline through the US to the Gulf, carrying the dirtiest type of fuel. Let us deal with the problems, should they arise, problem is no one has any plans in place on how to handle a disaster if one should occur, it would be outright devestating to our country not theirs, should we build now and deal with the disaster as it unfolds,or think ahead, address possible problems and how to fix them and then build...this pipeline would pose more of a threat then BP mess, just think how nice it will be to have this, accident waiting to happen, running through our backyards..... Good grief...
Good for them for going green, shame on them for not having the same respect for this country.

Marie W.
Marie W7 years ago

Somedays you need laws to get people to do things.

Brenda Morales
Brenda Morales7 years ago

I think this is a great idea. It could be a new way to have community gardens, too. My son and I were both talking about why we have so many black roofs, which absorbs the heat. I wonder if we will ever move to both vegetation and lighter, more reflective roof colors.

Valarie Snell
Valarie Snell7 years ago


ida w.
Ida Nga Sze W7 years ago

we need that in hotter places like hong kong as well.

Stefanie D.
Stefanie D.7 years ago

as to any relevance of reflective capacity of the lost/absent/reduced ice caps... it is near nil... because in WINTER, the all ice caps are fully in the DARK the entire time anyway.
in SPRING/AUTUMN, they are less contributing because they are at the shallowest inclination from the sun so reflection will vary by very little.
it is only SUMMER where a steeper incline that more reflection and absorption occur in proportion to solar light intensities, but this REDUCTION ONLY is lost on the EDGES of the polar caps, not further towards the poles.

keeping in mind, polar caps were not iced anyway for a long time as far back as the 1300/1400 A.D. Polar seas were ice-free (if not reduced nearly so), and Antarctica was at one time tropical anyway, even if more recently only partially frozen.