I was recently introduced to the work of Brenda Case Scheer – specifically a journal article she wrote called The Anatomy of Sprawl. If you’re the kind of person who enjoys geeking out about cities, this is for you. (Thank you Oliver.)

What she does in the article is break down the various components / layers of a city according to the rate in which they change. Her “spatio-temporal urban hierarchy” includes: site (slowest rate of change), superstructure, infill, buildings, and objects (fastest rate of change).

The way to think about this is that the bottom layers of a city – the paths and roads we have chosen to establish – are incredibly persistent. They don’t change all that often.

On the other hand, buildings do change. Old ones get demolished. New ones get built. There’s a cycle. They too probably feel pretty persistent in many cases, but in comparison to our roads, they change far more frequently.

The reason why all of this has bearing is because the paths we choose to carve out at the very beginning will ultimately dictate the kind of city that gets built and rebuilt over time.

The rectangular grid of Manhattan was planned out in 1811. Central Park was missing from this original plan, but it did establish the street network and ownership lots that are now so central to the identity of New York City. That was a 200+ year decision.

It seems to have worked out just fine for New York. But what if you’re in a position where the existing street network is viewed as failing and/or inappropriate for the future success of the city? 

Well that’s where things get interesting. Now you need to dig down to some of those base layers and work on changing the (frequently) unchangeable.