The pump room, morning

At eight the pump room is at its busiest, although nothing here moves fast. Every shower in the apartments, every cup at the restaurant counter and every kettle in the studio pulls water through these pipes at once. Both teal pumps are running, the needles on the gauges have climbed, and the copper pipework ticks quietly as hot water leaves the steel tanks for the floors above.

Below the welcome lounge is the room most visitors never see and every resident depends on. The pump room is concrete from floor to ceiling, lit by a row of caged bulbs, and the back wall is a map of the building's plumbing drawn in copper and steel. Pipes rise, bend, split and disappear into the ceiling toward every floor above.

On the left two teal pumps sit on concrete plinths, each with its own column of valves and fittings climbing the wall, and red valve wheels mark where the water can be shut off. In the middle a small steel vessel hangs among the gauges. On the right two tall stainless steel tanks hold hot water for the apartments, the restaurant and the studio, next to a red expansion vessel and a grey control panel with three green lights that should always stay green.

There is no furniture here and nothing to buy. This floor is in the tower because a building without one is only a picture of a building. When a tap opens in the apartment upstairs, something down here notices. When the restaurant's kettle fills at eight in the morning, a pump answers. The gauges are the closest thing the tower has to a pulse, and the pump room is the best place to understand how all the other floors keep working.

In the tower the pump room is the first basement, directly under the welcome lounge.