When Toronto’s Green Roof Dream Becomes a Nightmare.

istock_000000132606xsmallToronto City Council has mandated that as of January 2010, all new construction must have a certain percentage of the roof designated as a GREEN Roof. While the idea sounds great at the onset, I am pessimistic…as usual:

Developers are often short sighted. They know that they have a finite time to build and sell the property, making their profit as quickly as possible. Some are often known to take shortcuts and seldom see themselves involved in the property twenty years from completion. Most intend to be completely finished with the property within five years. (I often have to console Buyers who are looking for attention from their Builders and tell them that when buying new, “ By the time you get to closing, you have to realize that most Builders are working on the third or forth project down the line”).

That being the case, what happens when those GREEN Oasis’ have to be attended to 20 years from now?  Roofs are exposed to the elements and need constant maintenance at the best of times; add in to the mix that there will be roots and added weight of growing materials.

GREEN Roofs are a great dream but I pity the Condominium Corporation and their Board of Directors 20 years from now when they have to re-roof and replace what was originally built. Are GREEN Roofs a short term dream(20 years) or a nightmare?

Bob Aaron wrote an article on the same topic. Check it out!

Related Articles:

Common Sense is missed at City Council

City of Toronto on Canada Day Weekend

Sustainable Urban Design on Toronto’s Waterfront

Voting in Municipal Elections…

6 Replies to “When Toronto’s Green Roof Dream Becomes a Nightmare.”

  1. This is a fantastic idea however i have often thought of it slightly differently, that is each home or office should have acertain roof space dedicated to solar panels and each new home should have a built in composter.

    Each home/office with a solar panel will then be calcualted to see how much energy is produced annually and the homeowner / office will have the same amount as a tax deduction from their income. This way we save twice and help the national energy problem.

    So I am in support of the current ruling by the City Council.

  2. Richard, you present my view exactly. I look out from my home to a distant condo and see large trees on the roof and wonder what would happen in some of the severe wind storms we get if trees went over the edge? Big stink in the media but heck, trees on front yards collapse or big branches break off. If we allow that a roof needs replacement every 20 or so years, what do you do with mature vegetation, strip it off and start over? The tree huggers would go crazy. The costs to strip a green roof of all vegetation and materials are going to double the costs of the demolition part. Sorry, I love the idea of green roofs but I do not see them as practical. Plant a garden or forest on the ground and you just maintain it but plant it on a roof and you must kill it every 20 or so years? Makes no sense. Solar makes a much better alternative. Politicians do not think things out and are very short sighted.

    1. Hi, I am a Water Resource Engineer and don’t mean to be crude it seems you don’t fully understand the purpose of a green roof. Green roofs are not for beauty or biological diversity they are a form of infrastructure. To your point about trees on roofs, you are right, they are not practical, however trees are a very uncommon roof vegetative media and are usually implemented only at the request of the architect for their aesthetic appeal. Most vegetated roofs consist of grasses as there purpose is for storm water infrastructure (not mature plant). They do require maintenance (as all plants do), but should not require demolition and reconstruction after 20 years if the roof is built properly from the start. The zoning bylaw that the city implemented is a form of climate resilience in the coming years. Typically storm water infrastructure is the responsibility of the city (a multi billion dollar budget already), and it doesn’t seem unreasonable to enforce a very minimal amount of support from developers working on new construction projects that are one of the main contributors to the problem in the first place. I just think that developers should do their research before criticizing.

  3. So far, it’s like preaching to the choir. Think of all of the older condos that have to do major repairs because of leaks into underground parking as joints deteriorate, and that’s at ground level. Barry has enumerated some of the scary parts (tree going over the edge from 40 stories up?)…
    Solar panels would be a much better idea.
    Short term gain for long term pain…

    Guess this is par for the course for the pols at city hall (think of that great idea to double the land tansfer tax).
    The province is not far behind with harmonized tax grab.

  4. I lived in a building that had a garden over a portion of the parking and it has been an ongoing major project for the Corporation. I wonder if Buildings that already have GREEN Roofs (or gardens over the Building membranes) were ever part of this decision by Toronto City Council.

  5. Don’t want trees to fly over the edge of the building? Then don’t plant trees. Tree huggers don’t care about ripping up individual plants, they are concerned about the overall environmental state. If green roofs help save the environment but require maintenance or replacing every 20 years (I’ve heard it’s more like 40 years though) I still think that’s a better option. My condo building has gardens on several of our rooftop surfaces. Some are raised beds, and some are at foot level. I am in support of green roofs.

    Imagine taking your children strawberry picking… on the roof of your condo building!

Leave a Reply

Your email address will not be published. Required fields are marked *