Skip to content

Canadian Urbanism Uncovered

Bus shelters to show off green roof tech

Read more articles by

At least 6 bus shelters across the city have sprouted green roofs this week as part of a cute STM marketing campaign.

At least the STM has got something in this vein worth promoting: in 2008 the STM installed a 10,000 square foot green roof atop a new garage built in the Ahuntsic-Cartierville borough.

Green roofs can help insulate a building and provide savings on heating and cooling. Also interesting for a garage, green roofs can help with sound-proofing : by some estimates a 12-cm substrate can reduce noise by 40 decibels. The plant covering can also reduce wear on the structure, although the weight of a green roof (45 lbs per square foot) can be a concern to those who dream of a green roof on an older buildings (in comparison, snow weighs about 15 lbs per cubic foot).

From an environmental perspective, green roofs are absorbent, reducing the amount of rain water that winds up in our combined-sewer sewage treatment system (pretty much all the rain and snow that falls on the island gets the same treatment process as our toilet water). Green roofs also reduce urban heat-island effects and help filter particulate pollution out of the air (again, relevant for a garage). For a ton more information about the qualitative and quantitative benefits of green roofs, see “green roofs for healthy cities.

Even though I question whether the STM really needs to prove they’re “green”, it will be nice to see a patch of grass in the landscape, even if it’s above our heads. Hm, I wonder what would happen if we tossed in some wildflower seeds?



  1. I don’t think the point is that the STM needs to prove its “green”; it’s to market the STM as a service that appeals to people concerned with “being green.” Seems OK to me.

    Also, in the following sentence, are the units correct (i.e., one is lbs per sq. ft. and the other is lbs per cub. ft.)? “The plant covering can also reduce wear on the structure, although the weight of a green roof (45 lbs per square foot) can be a concern to those who dream of a green roof on an older buildings (in comparison, snow weighs about 15 lbs per cubic foot).”

    Forty-five decibels, eh? I should plant some grass above my ceiling and below my floor!

  2. Don’t know why the STM continually wastes money on things that don’t do a damn thing. You want to improve our city’s air, plant some trees, not temporary grass patches that will just go away whenever the STM finds an advertiser to pay them for the space.

    Want to reduce fraud? A one-time investment in unhoppable turnstiles would have been a much better idea than hiring small armies of ticket inspectors in faux-cop uniforms and paying them salaries in perpetuity. In fact, unhoppable turnstiles are pretty much better than Opus, which only succeeded in making our bus passes less resistant to wear and tear, our boarding queues slower, and did nothing for fraud… it pretty much served only to highlight that the people running the STM are idiots.

    Idiots who probably hired a consultant who told them about greenwashing. I don’t really believe they’d have the brains to figure it out on their own.

  3. And speaking of units, how about some metric ones please?

  4. The units are correct (though not metric, being from the american-based organization green roofs for healthy cities). The weight of thegarden is measured by square foot of garden space because isn’t necessarily a foot deep as well.

    To put it another way, the garden weighs about as much as a 1-meter layer of snow. And in the winter, the weight of the garden substrate be added to any snow buildup.

  5. In Toronto they came up with a better green roof for a bus shelter, the roof contains a solar cell, during the day it charges a battery, during the night there are lights in the shelter that come on using power from the battery,

    Grass has a big problem, it needs water, and if you have a hot dry summer, you end up with the grass dying, or you need a truck to go around and water the shelters. After the grass dies, you have a bunch of weeds taking over, until they rip it out and put in new grass.

  6. Oh, and a beautiful green roof on the STM garage off Cremazie. Thanks for pointing it out, Spacing.

  7. I absolutely agree that green roofs are FANTASTIC for the environment. They are a morale builder when people can enjoy them from an office, hospital, etc. In the right settings and environments, they make perfect sense. In this application…time will tell.

  8. I don’t think that these are meant to have any practical application. They’re as Niomi stated: cute marketing. The STM will probably only make a dozen or so.

    The new abribus were one of the 5 Shuko. The winning design can be found here:

    They’re quite nice: modular, solar-powered, and have the ability to tazer taggers and scratchitti ‘artists’ (I wish!).

  9. @ Alannah: Rather than wildflowers, I was thinking of some other seeds!

  10. Yes, grass needs water. Which is why most green roofs (of this scale and depth) don’t use grass. They use drought-resistant succulent plants, mostly sedum.

    Sedum, once established, can survive for a week or two with no rain. It will go dormant (like grass will), but perks back up with the next rainfall.

  11. Montreal bus shelters are filthy. And a great many date from the early-1970s when the STM’s colour scheme was brown and white. Nothing wrong with those designs. I kind of like them, better than the look of this current design, eco-friendly or not. The problem is they’re grimy and grafitti-laden. It’s almost like you could pick up a disease being in one! I at one time spotted a STM employee power-washing a shelter on Decarie and was shocked – shocked – the commission even paid this much attention to them. Of course even the larger & (relatively) newer shelters at places like Villa Maria are filthy.

Leave a Reply

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