Yesterday, Austin City Council voted 10-1 in favor of a building code amendment that will allow single-stair apartment buildings up to five storeys and with 4 homes per floor. This is progress. Austin now joins Seattle, New York, and possibly other US cities in allowing this building type, which is a type that is widespread outside of North America. Paris, for instance, allows single-stair buildings up to 50m.

In all of these newly allowable cases, there's usually a requirement to sprinkler the building and cap the number of homes per floor, among other life safety requirements. What I'm not clear on, though, is how flexible these new codes are in allowing larger apartment buildings.

In my opinion, it's better (and hopefully more accurate) to think about unit maximums on a per stair basis as opposed to a per floor basis. Because that's how you create larger point-access block buildings: you cluster multiple blocks together, each with its own exit stair. Is that allowed in these building codes? I'm not exactly sure, but one would hope.

Regardless of this important detail, I continue to be impressed by Austin's willingness to drive positive change in its housing market. It makes you wonder: What the hell is taking Toronto so long? Single-stair buildings up to 6 storeys should already be permissible. We should be leading.

Cover photo by Clark Van Der Beken on Unsplash

Point access blocks (or single-stair buildings) are now an important part of today's discussions around housing supply in Canada. They are seen as a way to encourage more and different types of housing -- something we have been talking about on this blog for years. Here and here are two recent posts.

This week, I discovered the work of Conrad Speckert, who works at LGA Architectural Partners and has become a leading voice for this movement. Conrad completed his M.Arch at McGill University and, as part of his thesis project, he developed this website called Second Egress.

Since then it has grown to become a major resource for point access blocks. But most importantly, it has evolved into a catalyst for change. On April 18, 2022, he and David Hine (of David Hine Engineering) submitted this code change request to the Canadian Commission on Building and Fire Codes.

The ask: Allow a single means of egress for multi-unit residential buildings up to 6 storeys. (The current maximum is 2 storeys.) Well done, Conrad and David. This is a massively important request with far-reaching benefits, and so I would encourage all of you to check out his website and spread the word.

P.S. My second favorite part of his site is a section called Manual of Illegal Floor Plans. It's a catalog of highly livable single-stair buildings from around the world; all of which would be currently illegal to build in Canada.

We have spoken before about buildings, such as this 6-storey one in Paris, that were allowed to be built with only a single exit stair. This is noteworthy because, here in Canada, if you were to try and build an equivalent 6-storey building on an equivalent 100 square meter site, you would be required to have two exit stairs. And that would create more non-leasable space and make it even more challenging to develop such a small building.

It is for this reason that single-stair buildings have been getting an increasing amount of attention as of late. They are seen as a way of encouraging more missing middle housing.

So where are single-stair buildings currently allowed? Below is a map from Seattle-based Larch Lab showing the maximum number of storeys for point access blocks (what they call single-stair buildings) around the world. Based on this, Canada is one of the most conservative countries on the planet when it comes to required exiting (I don't want to speak for any of the grayed-out countries). It also shows that much of the world allows 6 or more storeys.

Larch Lab is a major advocate for point access blocks and they have this policy brief outlining the problem and the opportunities. One of their most interesting statistics has to do with minimum project size inflation. As recent as 2000, only about 13% of all multifamily completions in the US had more than 50 units. Today, this number has jumped to more than 55% of all new multifamily buildings, meaning we are quickly losing our ability to build small and intimate.

Point access blocks can help with this.

Of course, the reason we have exiting requirements in our building codes is because of life safety. But there's research to suggest that this level of redundancy may not be needed in certain buildings. According to the above policy brief, the average death rate (caused by a building) in point access block countries like Switzerland, France, Italy and Germany, is significantly lower than that of the US. On top of this, almost no countries in the EU require buildings less than 28m tall to be sprinklered. The US does.

All of this said, I don't think that single-stair buildings are a silver bullet for missing middle housing. It is just one important ingredient in a complicated recipe. And as evidence of this, we can look to Seattle. The 2018 Seattle Building Code allows point access blocks up to 6 storeys, which is a rare occurrence in the US. However, the city appears to be still working on missing middle reform. Presumably other ingredients are still -- missing.

Image: Larch Lab