Regulation 10 of the Workplace, (Health Safety and Welfare) Regulations 1992 states the following with regards to room dimensions and space requirements:
Every room where persons work shall have sufficient floor area, height and unoccupied space for purposes of health, safety and welfare.
The associated Approved Code of Practice and Guidance goes on to state:
Workrooms should have enough free space to allow people to get to and from workstations and to move within the room, with ease. The number of people who may work in any particular room at any one time will depend not only on the size of the room, but on the space taken up by furniture, fittings, equipment, and on the layout of the room. Workrooms, except those where people only work for short periods, should be of sufficient height (from floor to ceiling) over most of the room to enable safe access to workstations. In older buildings with obstructions such as low beams the obstruction should be clearly marked.
The total volume of the room, when empty, divided by the number of people normally working in it should be at least 11 cubic metres. In making this calculation a room or part of a room which is more than 3.0m high should be counted as 3.0m high. The figure of 11 cubic metres per person is a minimum and may be insufficient if, for example, much of the room is taken up by furniture etc.
The figure of 11 cubic metres does not apply to:
In a typical room, where the ceiling is 2.4m high, a floor area of 4.6m2 (for example 2.0 x 2.3m) will be needed to provide a space of 11 cubic metres. Where the ceiling is 3.0m high or higher the minimum floor area will be 3.7m2 (for example 2.0 x 1.85m). (These floor areas are only for illustrative purposes and are approximate).
The floor space per person indicated above will not always give sufficient unoccupied space, as required by the Regulation. Rooms may need to be larger, or to have fewer people working in them, than indicated in those paragraphs, depending on such factors as the contents and layout of the room and the nature of the work. Where space is limited careful planning of the workplace is particularly important.
L24: Workplace Health, Safety and Welfare Regulations 1992: Approved Code of Practice, ISBN 9780717604135, priced at £5.75.
A free booklet is also available: INDG244, Workplace Health, Safety and Welfare a Short Guide. This leaflet can be downloaded online.