The Quay Quarter Tower in Sydney has been just been awarded the "best new tall building" of 2023 by the Council on Tall Buildings and Urban Habitat (CTBUH). Deigned by 3XN and BVN, it's a great adaptive reuse story.
The project is a renovation and expansion of an existing 1970s building. And the team managed to retain 65% of the original structure (slabs, columns, and beams) and 95% of the original core.
This results, according to their calculation, in 12,000 tons of embodied carbon savings. The equivalent of 35,000 flights between Sydney and Melbourne. At the same time, the team managed to add 45,000 m2 of new floor area to the site by grafting new slabs onto the existing ones.
But let's get back to these carbon savings.
According to this site, there are 37 direct fights between Sydney and Melbourne each day. That's about 13,505 flights per year, meaning that the carbon savings from not fully demolishing this building (and starting fresh) are equal to about 2.6 years of people not flying back and forth between these two cities.
If you consider how long buildings typically last (this one was relatively young at under 50 years), it kind of makes buildings seem less bad. Of course, we're only talking about and comparing embodied carbon. There's also the ongoing operation of the building.
In any event, a deserving project. Congrats to the team. For more on the project, click here.
Photo via Dezeen
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