Back in 2016, the New York Times published an article where it cited that at least 40% of the buildings in Manhattan could not be built today because they don't conform to the city's zoning code for one or more reasons. These reasons might include too much density (FSI / FAR), too many units, inadequate setback requirements, or something else.

This is a tricky number to estimate as most cities don't track it, but I asked Gemini and Claude to try for Toronto, and they returned 70-80% and 45-55%, respectively. Claude's estimate seems to be lower because it assumed that all of the subdivided single-family houses are now legal because of the new multiplex permissions.

I don't know about that, but the point is that there's a meaningful, non-zero quantity of buildings in our cities that we decided to make illegal, and generally difficult, or impossible to build again. The thing that I'm most interested in dissecting is: why?

Here's one way to look at it. My follow-up question to both AI models was: What percentage of buildings within a Heritage Conservation District would you say are illegal to build in Toronto today? And both models agreed that the number is 90%+, and probably very close to 100%.

Heritage Conservation Districts are a way of saying "these buildings and this urbanism is so good, that it's worth preserving through extra layers of planning protection." But at the same time, our other policies say, "you shall never build anything like this ever again." It's incoherent.

A more coherent approach might be to call them Heritage Renewal Districts where we instead codify the following: "this district is now illegal based on our current planning rules and so the objective is to tear it all down and replace it with new, approved buildings." Sounds like blasphemy, doesn't it? So then why block more of it?

If it's worth conserving, then it's worth building more of. What ought to be obvious is that we need more rather than less planning flexibility, and we need to legalize the things that have been proven to work, like traditional fine-grained patterns of city-building.

Cover photo by Ayman Hallak on Unsplash