Kelly Alvarez Doran shared this article with me on Twitter earlier today. It talks about some of the work that his design studios are doing at the University of Toronto around embodied carbon. More specifically though, his studios are being tasked with figuring out how to halve the carbon emissions generated by new buildings during this decade.
And one of the big findings from his studio is exactly the title of this post: our buildings have become carbon icebergs. Here in Toronto, we tend to build a lot of below-grade parking. We recently got rid of parking minimums (which obviously needed to happen), but the market still demands it in certain areas and for certain projects. So we continue to build it.
What the above section drawings are showing is the percentage of carbon emissions resulting from the below-grade construction component in each project. And as you can see, the numbers are significant, particularly in the case of smaller mid-rise buildings where you don’t have a lot of above-grade area to grow the denominator.
Looking at 2803 Dundas Street West, which is just down the street from our Junction House project, the number is 50%! And sadly, I would guess that our project is probably only marginally better; we’re a bit taller up top, but we also have a raft slab foundation and a watertight below-grade.
This is one of the reasons why I recently tried to make the case for above-grade parking. A big part of my argument was that if we want parking that can be adapted to other uses in the future, and if we want to reduce the embodied carbon in our buildings, then we should be building “unwrapped” above-grade parking. That is, parking which isn’t hidden behind other uses.
But this is often frowned upon in planning circles and it’s not going to be feasible in smaller mid-rise buildings like the ones shown here. We’re also just talking about what is less bad. What we really ought to be doing is trying to build our cities so that people don’t need to rely so heavily on cars to get around.
Image: Ha/f Studio
Hi Brandon, this was an interesting post and agree with your carbon comments about the carbon in below grade construction. And that we really want a city where we don’t need the parking levels because cars are needed as much. What I couldn’t understand was that in the top 3 diagrames, the embodied carbon was so much higher than 50% and couldn’t understand why. Can you explain.