The question was prompted by a CBC News story titled "Welcome to the 15-minute neighbourhood" about Ottawa's plan to manage growth by thickening up its existing neighborhoods instead of expanding outward into farther-flung suburbs. But a quick Google search turns up other examples of the concept: visions for 15-minute neighborhoods in Boulder and 20-minute neighborhoods from Portland to Detroit and beyond.

In Ottawa, they're calling it "intensification," and the intent is to bring the necessities of life within easier reach of residents, both existing and new, without having to build a lot of costly new infrastructure. Ottawa is trying to do what Minneapolis planner Paul Mogush memorably describes as: “Put the stuff closer together so it's easier to get to the stuff.”

And the time for this approach is long overdue. All across North America, we have bankrupted our cities and states by putting the “stuff” ever farther apart, and then building huge networks of roads and pipes to connect it. Our cities have ballooned in physical size far faster than they've grown in population, and face ever-mounting maintenance costs for all that pavement, at the same time as residents clamor for yet more roads to deal with congestion caused by all the driving we’ve forced ourselves to do.

The intent of the 15-minute neighborhood movement is to break out of this mobility trap—the vicious cycle of driving ever longer distances to get to the same things—and get back to building places around the most ancient, versatile, guaranteed-to-always-be-relevant transportation method there is: two legs. (And for those with disabilities, let's be clear that building for two legs and building for two wheels can and should go hand in hand.)

The massive response to our Facebook post makes it obvious to us that the 15-minute neighborhood principle has tons of appeal. But how do you get there? Especially if your city is already laid out in such a way that many existing places fall far short of that 15-minute ideal?

We compiled this list of 7 rules for what a city of 15-minute neighborhoods needs, with links to some of our best articles over the years. And these aren't just for planners or developers—you'll see in here that there are things an average citizen can also do to bring their neighborhood a bit closer to being a 15-minute neighborhood.

1. Bring back the neighborhood school.