There are rules about the maximum number of people who can work in one room. Of course, it depends a great deal on what the work is - the layout, furniture, fixtures and fittings required, but the basic calculation is - the volume of the room (when empty) divided by the number of people working in it should be at least 11 cubic metres (with 3.0m taken as the maximum height, even if the ceiling is higher than this). This calculation can be found in the Workplace (Health, Safety and Welfare) Regulations 1992 Approved Code of Practice.
The rule of thumb is that workrooms should have enough space to allow you to get to and from your workstations and to easily move within the room.
And within the room workstations should be arranged so that any task can be done safely and comfortably. You shouldn’t need to bend or stretch unduly, so work materials and frequently used equipment or controls should be within easy reach. You should be able to stand at your workstation and have freedom of movement. And when seated your lower back should be supported and you should be able to work with your feet comfortably placed flat on the floor, or be given a footrest if this is not possible.