If you run a construction site in the UK, welfare isn't optional and it isn't vague. Schedule 2 of the Construction (Design and Management) Regulations 2015 lists exactly what has to be provided, and the HSE inspects against it. Here's what it says, in plain English, and what it means for your site.
Suitable and sufficient toilets, ventilated, kept clean, with separate facilities for men and women unless each toilet is in a lockable room. "Sufficient" scales with crew size: one toilet doesn't cover a twenty-person site.
Wash basins with hot and cold (or warm) running water, soap and a way to dry hands, close to the toilets and to any changing areas. If the work is particularly dirty or involves hazardous substances, showers may be needed.
Wholesome drinking water, clearly marked, with cups unless it's a fountain. Bottled water on a hot day is a gesture, not a system.
Somewhere to change if workers wear special clothing, and somewhere secure to store their own clothes and site gear. Wet gear needs somewhere to dry.
A rest area with tables and seating for the number of people likely to use it at once, a way to boil water, and a way to prepare or heat food. In practice: a canteen with a kettle and a microwave, out of the weather.
The contractor in control of the site must provide the facilities, but responsibility runs wider than most people think. Under CDM 2015 the client has a duty to ensure welfare arrangements are in place before work starts, and the principal contractor carries it through the build. "The client wouldn't pay for welfare" is not a defence anyone has successfully run.
Yes. The requirement is proportionate, not optional. A two-person, two-day job doesn't need a 16ft cabin, but the crew still needs access to a toilet, washing and rest facilities. Sometimes that's genuinely arranged with a nearby premises, in writing, actually available, not a vague nod towards the petrol station. Where it can't be, a compact unit like our 6ft welfare box is the honest answer, and often cheaper than the argument with an inspector.
Welfare failures are among the most common enforcement notices on small sites precisely because they're the easiest thing to check: an inspector can see within two minutes of arriving whether a site takes it seriously.
A self-contained welfare unit puts the whole Schedule 2 list in one box: chemical toilet, hot water hand wash, canteen with kettle and microwave, drying and storage space, powered by its own generator so it works on sites with no mains. Delivery, servicing and waste are handled through the hire, which also deals with the "kept clean" requirement without anyone on your crew drawing the short straw. See the units, or get a fixed weekly price for your site.
This guide is a plain-English summary, not legal advice. The regulations themselves are on legislation.gov.uk (CDM 2015, Schedule 2) and HSE guidance is at hse.gov.uk.