It’s easy to think of the built environment as (relatively) static, as fixed, as unchanging. To do so discounts the whole building, that is, the building in its entirety. We must learn to see buildings four-dimensionally. To understand our buildings, we must travel with them through time—both through centuries and through seconds.

The above sign is a rare one because the four-dimensional building so often operates in a kind of permanent pantomime, hiding its inactivity, its off-peak periods, its resting state behind a façade of liveliness. That feeling of walking through a lobby early in the morning, a grocery store late at night, a stadium after the last fans have left—that quiet feeling of intrusion, of behind-the-scenesness, that is the building at rest. This is different from abandonment (which is death? coma? When is a building dead?); the restful building still has a feeling of low-level activity, a buzz of preparedness about it. The building is inactive, but ready to be active again.

We are constrained by our biases, our modernist tendencies for perfect lines and clean geometries. Nothing is perfect; less is clean. Like our bodies, like our world, our buildings have a cycle to them, an ebb and a flow. We learn the cycle when we see four-dimensionally, when we can look forward as clearly as we look back. Doing so is necessary to understand not just how our world looks, but the processes by which our world operates.