Employers must provide toilets and washing facilities scaled to headcount, drinking water, somewhere clean to rest and eat meals, and changing, shower and drying facilities where the work requires special clothing or is dirty. That is the Workplace (Health, Safety and Welfare) Regulations 1992 in one sentence. The rest of this guide turns each duty into the numbers a building actually needs.
HSE's guidance to the Regulations sets provision by the number of people at work. Where facilities are shared by men and women, each toilet needs to be in its own lockable room. For male-only provision, urinals can substitute for some toilets, which usually reduces the footprint.
| People at work | Toilets | Wash basins |
|---|---|---|
| 1 to 5 | 1 | 1 |
| 6 to 25 | 2 | 2 |
| 26 to 50 | 3 | 3 |
| 51 to 75 | 4 | 4 |
| 76 to 100 | 5 | 5 |
| Over 100 | Roughly one more toilet and basin per additional 25 people | |
These are minimums for facilities that are readily accessible from the work area, kept clean, lit, ventilated, and supplied with hot and cold (or warm) running water, soap and a means of drying. Shift patterns matter: the numbers should work at the busiest point of the day, not on average.
Every workplace needs a suitable rest area with enough seating for the number of workers likely to use it at one time. Where workers regularly eat meals at work, there must be suitable facilities to eat them, kept clean and away from contamination risk, with a means of heating food or getting a hot drink where none is available nearby. In practice, on factory, warehouse and processing sites this duty is met with a canteen or mess room: seating for the largest break sitting, tables, a servery or kitchenette run, fridges, and hand washing on the route in. Sizing that room correctly is its own subject, covered in our staff canteen buildings guide.
Changing facilities are required where staff wear special work clothing (overalls, whites, PPE beyond the trivial) and cannot reasonably change elsewhere. They must be readily accessible, provide seating, secure storage for personal clothing, and separate rooms or separate use for men and women. Showers are expected where the work is dirty, strenuous or carries a contamination risk, and food processing sites usually need them as part of hygiene control. Where workwear gets wet in normal use, drying facilities are expected too. In building terms this becomes a changing room per sex with lockers and bench seating, showers off the changing rooms, and a heated, ventilated drying room sized to the wet-gear load.
Put the duties together and the building writes its own room schedule: WCs and basins from the headcount table above, a canteen sized to the largest sitting, changing and drying scaled to how many people wear workwear, and an accessible WC. That schedule, not the shell, is what drives the size and cost of a welfare building, which is why we quote from headcount and shift pattern rather than from floor area. See how we design, supply and install them on the staff welfare buildings page, or send us your numbers for a compliant layout and a fixed quote.
About Cabinworx. Cabinworx designs, supplies and installs steel and timber frame modular buildings across the UK, from welfare and canteen blocks to classrooms, nursery rooms and sanitary buildings. Steel cabins come in our Classic and Plus ranges, timber frame in Standard and Premier, and every building is delivered and installed on a prepared base by our team.
Staff welfare buildings: design, supply & installTell us the number of staff, the shift pattern and what the work involves. We come back with a compliant room schedule and a fixed quote, usually within two working days.