But not everyone can return at once: banks will have to extend practices like those used for small teams of traders during the pandemic. Shifting rotations of people will pass through giant buildings on different days, without clustering in the same areas on the same floors, to avoid spreading COVID-19. Some of the banks are implementing systems where employees will book “hot seats” on particular days and be monitored while they are sitting at them, sources said.

In some buildings, that could mean cameras that monitor a room’s occupancy level and even sensors that tell building management whether someone is sitting at a desk. “That feels a little personal,” one bank employee said about desk sensors.