The person considered by an occupancy calculation is not the person as they are encountered socially or experientially. Characteristics such as familiarity, vulnerability, discomfort, intention or interpersonal relationship are irrelevant to the calculation. What matters is that a body occupies a calculable share of space and must be able to leave under particular conditions. I refer to this as an operational body: the version of a body constructed by a system in order to perform a particular operation.

The operational body is not necessarily a false representation. Its reduction is precisely what makes the calculation useful. Fire-safety regulation cannot account for the complete lived experience of every person occupying a room. It needs bodies to become comparable enough for questions of capacity, circulation and evacuation to be calculated. In this sense, the process encountered in Breathing Room is not exceptional. Spatial environments are already organised through systems that translate bodies into operational categories.

The fire regulation needs a body that can occupy and evacuate space. My prototype needs a body that can enter, leave and be counted. Neither needs all of me. They need enough of me to operate. This changed how I understood the threshold number

Ten is not the answer to how many people belong in 12 m². Ten is the point at which this particular system has been told to respond. And somebody had to tell it.

While reading Ursula Franklin, I came across a sentence that made this suddenly uncomfortable: “And what is right is laid down beforehand, by others.”

I had been thinking about the room as responsive and interactive. Someone enters. The room notices. The room responds. It sounds almost as though the decision belongs to the room. But the room never decided that ten should matter.

I decided what the sensor should notice. I decided that an interrupted beam could stand for a person crossing a boundary. I decided that a person could become +1. I decided that ten of those ones should trigger a response. And I decided what that response should be. By the time somebody enters Breathing Room, much of what the room appears to “decide” has already been decided.