I tweeted this yesterday (please forgive the grammar mistake).

What it shows is a bunch of narrow urban properties ranging, for the most part, from 5 to 7 storeys. Some of them are old buildings, and some are new. Regardless, the point I wanted to make was that this is a scale and rhythm of building that does wonders for cities. They’re dense, they have a compact footprint, and they promote urban vibrancy.

And yet, it's a building type that is far too difficult to develop in many cities. It is not always the case, but oftentimes the only way to underwrite these kinds of projects is to make them ultra high-end. That's a shame. So let’s talk about this a little more, starting with what makes this urban pattern so appealing.

One key thing that narrow lots and narrow retail frontages do is increase the number of destinations within walking distance. This promotes visual interest by always showing you something new.

At the same time, there are numerous economic benefits to this urban pattern. Smaller shops lower the barrier to entry for small businesses and allow greater adaptability. Change is able to happen faster, and if one or two businesses happen to turnover on a street, it’s not the end of the world.

One way I like to think of this is in terms of shops per step.

For example, let's assume that the average walking speed is 4 km/hour and that, as a starting point, fine-grained urbanism translates into storefronts that are around 6 m wide. This would mean the average person walking on a street would see a new shop (or retail frontage) about every 9 steps.

If we instead assume a retail frontage of something like 30 m (which is five times our original 6 m), then the average person would need approximately 43 steps for every shop. This is a meaningful difference that fundamentally changes the character of a street. If you’ve ever walked on a great main street, you know this, even if you’ve never explicitly acknowledged it.

But this is only the ground floor. The other benefit of these simple, straight-up infills is that they also bring homes and offices to the same compact footprint. Density is good. It is a prerequisite for urban vibrancy. And it can be achieved simply. Strip away the facade ornament from the building examples in my tweet, and these are extruded boxes with no stepbacks to speak of.

Cities used to be adept at creating fine-grained, walkable, mixed-use streets. In fact, if you look at old photos, you'll see it was the norm. But that has become increasingly difficult for a variety of reasons, ranging from parking and servicing requirements to overall suburbanization and chain retailers demanding certain spaces. Today, in many parts of the world, these kinds of streets are by far the exception rather than the rule.

What hasn't changed, however, is our appreciation for human-scaled spaces. This raises the question: How can we create more of them going forward? How might we make more Ossington Avenues? This is especially relevant as many cities look to intensify their existing neighborhoods. More housing is essential, but there are also broader city-building opportunities that can come along with it.

The first thing to keep in mind is that developers will always have a bias toward what is most profitable and what has the least amount of risk. So if a residential apartment at grade is going to be more profitable than a cute coffee shop, developers will build the apartment. But markets and areas do change, and sometimes what didn't make sense before makes sense today.

Let's, for example, return to our discussion of Ossington Avenue. At the intersection of Ossington and Halton, there is a stacked townhouse development that was built just prior to Ossington becoming the cool-ass street that it is today. One of the ways you can tell its vintage, I think, is that it has no retail fronting onto Ossington. Instead, it has townhouse balconies that are likely to remain there until the end of time. If it were built today, I bet you that the developer would have built ground-floor retail.

But you can't really blame the developer. At the time, it likely didn't make economic sense to build retail. Few could have predicted Ossington would become what it is today. And it is this messiness and unpredictability that makes cities so great. But it's also what makes top-down planning difficult. Nobody can predict the future, and nobody knows exactly what the market will want.

As far as I know, a bunch of people didn't sit down in a boardroom and outline how they were going to transform Ossington through top-down planning. It was local change agents who started doing things. And once they had found what the market wanted, it was the people in boardrooms who reacted with, "This is too successful; we better put in place a moratorium on bars and restaurants."

What made Ossington successful was that it had the right "bones" and the ability to be transformed. It allowed for bottom-up change. And if there's one thing to take away from this post, it's that. If we want a chance at creating more Ossingtons, we should be focused on (1) creating the right preconditions in new developments and in our land-use policies, and then (2) getting out of the way through fewer rules and more flexibility.

A good land-use model to consider is that of Japan. By default, most zones are mixed-use and most low-rise residential zones allow "small shops and offices." Because, why not? Of course, not every street can be an Ossington, and not every street can support fine-grained retail. But we won't know exactly what's possible unless we allow our street frontages to evolve along with our cities.