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Welfare Provision Calculator

Calculate welfare facilities required under CDM 2015

How We Calculate This

Enter the number of workers on site and the project duration. The calculator applies the ratios used in the HSE Construction Welfare Standards: 1 chemical closet per 7 workers (weekly emptying, BS 6465-1), wash basins at 1 per 10 up to 50 then +1 per 20 (heavy soiling foreseeable in construction), a rest area at 1.0 m² per person (AD-B Appendix C floor-space factor, 4 m² minimum), and an estimated drinking-water volume of about 1.2 L per person per day (NHS guideline). First-aid provision follows INDG214 Table 2 for higher-hazard work: fewer than 5 workers → an appointed person; 5 to 50 → a trained first-aider; over 50 → one first-aider per 50. Separate toilets for female workers and drying facilities for projects over 2 weeks are added automatically.

Frequently Asked Questions

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Last updated: March 2026

Verified against UK standards · estimates only, confirm with your supplier.