I was in the mood for some light reading before bed earlier this week, and so I pulled out this comparative critique of Euclidean zoning. Many of you are probably familiar with how single-use zoning works. It is the dominant form of zoning in North America and it is predicated on the idea of "everything in its place." Meaning, land uses are best off when they are segregated and put into distinct zones: commercial here, industrial over there, residential in these areas, and so on.

But there are a whole host of arguments for why this is bad cities. Among other things, it makes them less sustainable, because typically you need to drive between zones when you want to do things. It makes them less resilient, because you've now created monocultures. And it also encourages segregation, because if this zone is only for 2-acre single-family lots, then only people who can afford a 2-acre lot get to live there.

I'm sure that many of you are already aware of these arguments. So what I found most interesting from this light bedtime reading was the comparison to the French model of urbanism. One of the key differences in cities such as Paris is that the French have historically preferred to zone for structures over uses. In other words, aesthetics and how buildings look have long been a priority, but what happens inside of them has been less of one.

The result is an incredible mix of uses that makes the city what it is today. And this is perhaps the great irony of Paris. Its visual harmony might make you believe that "everything is in its place." But really things are often all over the place -- as they should be in a city. Adding to this irony is the fact that many single-use cities do not actually appear very orderly, even though they're kind of supposed to by design.

I thought this was an interesting way of looking at these two different models of urbanism. It makes the case that not everything needs to be in its place; maybe it just needs to look that way and the rest will figure itself out.