I was having a conversation recently with someone who demanded to know what works. His statement was something like: Come on, Chuck. You’ve studied this stuff for years. You’re the expert. Just tell us what works already.

The question was a little like the annoying old density question—”What is the precise density necessary to create a Strong Town?”—which I’ve been asked for years, and which I long ago addressed in a post. It also danced near an important question of our time: Whose expertise matters? I’ll answer that one quickly.

In a time when society is tasked with efficiently replicating a set pattern of development, the technical professional is the expert. They can live in their hierarchical silo with their narrow but deep expertise and feel confident in simply repeating what they know how to do. That was the case during the time period immediately after World War II, in which American suburbs began to expand at an unprecedented pace. The expert-led approach accomplished what it attempted to do—create rapid growth as a way to keep us from sliding back into economic depression.

In a time when society is tasked with maturing the development pattern, of making increasingly productive use of that which has already been built, the everyday citizen becomes the expert. They are the only ones capable of understanding the fractal minutia of their own place. Technical professionals must evolve to be less like all-knowing rulers and more like humble servants. I’ve written about this extensively as well.

So, the way I would answer the question of “what works” is to start with this sketch of a mature city by the great architect Leon Krier.