Once bodily presence has been translated into a count, a further operation becomes necessary. The number alone cannot determine how an environment should respond. It has to be given meaning through a rule.

This became apparent when establishing the occupancy threshold for Breathing Room. The proposed installation would occupy approximately 12m². An initial survey of public-space and fire-safety guidelines suggested approximately one person per square metre as a recurring, though not universal, occupancy factor. Rather than using twelve as the threshold, I set the prototype to respond at ten people, corresponding to approximately 1.2m² per person. The number was therefore not arbitrary, but neither was it a neutral measurement of how much personal space a body requires.

A wider comparison of occupancy regulations complicated this assumption.² Occupant-load calculations vary substantially according to jurisdiction and, importantly, according to the anticipated use of a space. A room in which people stand, sit, dine, circulate or gather for an exhibition may be assigned different occupancy factors. Such calculations are generally designed for operational purposes such as evacuation and fire safety rather than to determine an appropriate interpersonal distance. Before the regulation can calculate bodies, it therefore has to classify the situation in which those bodies are expected to act: room → occupancy type → assumed bodily activity → spatial allowance → occupant load

This produces a particular kind of body.

There was no universal answer when I tried to understand where my supposedly reasonable number had actually come from. Occupancy calculations change from place to place, but they also change according to what a room is expected to be for. Standing, sitting, eating, dancing, circulating, watching—different activities produce different calculations. Before a regulation can count bodies, it has to imagine what those bodies are doing.

A room becomes a type of room. A body becomes a type of body. And eventually, a person becomes +1. This is a strange transformation. The +1 does not know whether I am comfortable. It does not know whether the person beside me is my partner or a stranger. It does not know whether I want somebody closer or further away. But that does not make the +1 useless. Once I become +1, I can be added. I can contribute to a capacity. I can cross a threshold. I can make a rule happen.

I began to think of this version of the body as an operational body: not the body as it is lived, but the version of it a system needs in order to do something.