How Buildings Learn: What Happens After They're Built

by Stewart Brand

Dome apostate Lloyd Kahn rediscovered verticality: “What’s good about 90-degree walls: they don’t catch dust, rain doesn’t sit on them, easy to add to; gravity, not tension, holds them in place. It’s easy to build in counters, shelves, arrange furniture, bathtubs, beds. We are 90 degrees to the earth.”16 Occupants are always intuitively oriented in rectangular buildings. (Orientation itself is a right-angle concept, the cardinal directions being at 90 degrees.) Since buildings inevitably grow, it is handy to have the five directions (including up) that rectangular buildings offer for expansion. Right-angled shapes nest and tile with each other universally, so tables fit into corners, and clothes into closets, and buildings into city lots, and lots into city blocks. Humanity’s first cities in Sumer had rectangular street grids.