Posted By Richard Mathews
I don't know about any industry averages but see this extract from the Workplace (Health, Safety and Welfare) Regulations and the HSE ACoP and Guidance.
Regulation 10 Room dimensions and space
(1) Every room where persons work shall have sufficient floor area, height and unoccupied space for purposes of health, safety and welfare.
(2) It shall be sufficient compliance with this regulation in a workplace which is not a new workplace, a modification, an extension or a conversion and which, immediately before this regulation came into force in respect of it, was subject to the provisions of the Factories Act 1961, if the workplace does not contravene the provisions of Part I of Schedule 1.
Minimum space
76 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.
77 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 3.0 m high should be counted as 3.0 m 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.
78 The figure of 11 cubic metres referred to in paragraph 77 does not apply to:
(a) retail sales kiosks, attendants' shelters, machine control cabs or similar small structures, where space is necessarily limited; or
(b) rooms being used for lectures, meetings and similar purposes.
79 In a typical room, where the ceiling is 2.4 m high, a floor area of 4.6 m2 (for example 2.0 × 2.3 m) will be needed to provide a space of 11 m3. Where the ceiling is 3.0 m high or higher the minimum floor area will be 3.7 m2 (for example 2.0 × 1.85 m). (These floor areas are only for illustrative purposes and are approximate.)
80 The floor space per person indicated in paragraph 77 and 79 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.
Richard