Downtown Toronto has a dense core of tall, glassy buildings along the waterfront of Lake Ontario. Outside of that, lots short single family homes sprawl out in every direction. Residents looking for something in between an expensive house and a condo in a tall, generic tower struggle to find places to live. There just aren’t a lot of these mid-sized rental buildings in the city.

And it's not just Toronto -- a similar architectural void can be found in many other North American cities, like Los Angeles, Seattle, Boston and Vancouver. And this is a big concern for urban planners -- so big, there's a term for it. The "missing middle." That moniker can be confusing, because it's not directly about middle class housing -- rather, it's about a specific range of building sizes and typologies, including: duplexes, triplexes, courtyard buildings, multi-story apartment complexes, the list goes on. Buildings like these have an outsized effect on cities, and cities without enough of these kinds of buildings often suffer from their absence.

The Missing Middle