One of the trademarks of Tokyo's urban landscape is a lot of exterior exit stairs. For example, our hotel is almost 20 storeys and it has two exit stairs, both of which sit outside of the building. Here's a photo taken from the corridor. You can also see other buildings in the background with similar exit stair configurations.
Oftentimes these stairs will also be positioned on a building's primary elevation, making them form part of the overall architectural expression. There's no shame in doing that here. This is curious to me because it means that, on tight urban sites, you're giving up part of your frontage to egress. The alternative would be to burry it in the middle of the building and have it transfer over at some point.
In any event, my first thought when I see a lot of exterior circulation is usually that the place must have a mild climate. And indeed, this is true of Tokyo. The average January and February lows and highs are 10 degrees and 5 degrees, respectively. Snow is extremely rare here. But that doesn't seem to be what's driving this egress approach.
Because if you go up north to Sapporo, where they get upwards of 500cm of snow each year, it too has exterior exit stairs. Closer to home, there's also the example of Montreal, which is similarly known for its exterior stairs (both in its older housing stock and in some of its newer housing stock). So it can't just be a weather thing.
The more likely hypothesis is that it's simply cheaper and easier to build this way. There may also be local regulations that either directly or indirectly encourage it, beyond it just being more cost effective. Interestingly enough, though, exterior stairs don't seem to be as common in newer buildings (but this is just my anecdotal observation from the last few days).
We talk a lot these days about single-stair buildings. And I think it's clear that we need to start allowing this for larger infill projects. But Tokyo also has me wondering if we should be having a parallel conversation about more open-air exit stairs and corridors. Climate is clearly no excuse. If it can help bring down the cost of building, then it's something to consider.
