Summary
- Part T is the newest Approved Document (made 2024, applying to relevant building work from 1 October 2024): it requires suitable toilet accommodation in new non-domestic buildings and certain material changes of use — favouring single-sex toilets, with universal (self-contained, fully enclosed) toilets where space allows.
- It does not apply to dwellings — but small practices doing shop fit-outs, offices, cafés and community buildings are squarely in scope.
- Mixed-sex shared facilities are no longer acceptable in new relevant buildings except as universal toilets; the space planning consequence lands at Stage 2, not fit-out.
What the Building Safety Act requires for Part T on non-HRB jobs
Requirement T1 applies to new buildings other than dwellings, and to some material changes of use, where toilets are provided for people using the building. The policy intent is clear: single-sex toilet accommodation as the default, with universal toilets — fully enclosed, self-contained rooms with their own basin — provided in addition or, where space genuinely constrains, as the alternative.
For small commercial work — a café conversion, an office refurbishment creating a new building unit, a village hall — the design consequence is that the old economising move of a single shared lobby with mixed cubicles no longer complies for new relevant buildings. The counting rules interact with occupancy figures, so the sanitary strategy must be settled when the layout is, alongside accessible WC provision under Part M Volume 2 and BS 8300-2.
As Principal Designer (BSA), your evidence is the applicability decision (Part T has exclusions, including dwellings and some small premises), the occupancy-based provision calculation, and the layout demonstrating single-sex/universal provision. This is a young document and Building Control interpretations are still settling — recording your reasoning matters more than usual.
Key design risks and evidence needed (RIBA Stages 2–4)
- Stage 2: applicability check (new non-domestic building? relevant change of use?) and first-pass sanitary count from expected occupancy; reconcile with Part M accessible WC needs.
- Stage 3: layout showing single-sex provision and/or universal toilets with full-height enclosure and in-room basin; privacy check — no urinals or cubicle sightlines from circulation on door opening.
- Stage 4: sanitary schedule and details; universal toilet room sizes; door, lock and washbasin provision per AD T; coordination with Part G (hot water, sanitation) and Part H (drainage).
Standards and references you should be citing
- Approved Document T (2024) — provision, privacy and layout requirements for toilet accommodation in non-domestic buildings.
- BS 6465-1 — sanitary installations: scale of provision (the counting reference for appliance numbers).
- BS 8300-2:2018 — accessible sanitary facilities, alongside Approved Document M Volume 2.
- Workplace (Health, Safety and Welfare) Regulations 1992 — the parallel HSE provision requirements for workplaces.
Toilet types under Part T
| Type | Definition | When required/acceptable |
|---|---|---|
| Single-sex toilets | Separate male/female rooms; cubicles may share the single-sex room | The default provision in new relevant buildings |
| Universal toilet | Self-contained, fully enclosed room with WC and basin | In addition to single-sex; or instead where space is genuinely constrained |
| Mixed-sex shared cubicle areas | Cubicles off a shared circulation/wash area | No longer acceptable in new relevant buildings |
| Accessible WC (Part M) | Doc M compliant wheelchair-accessible WC | Required in parallel — Part T does not replace it |
Common pitfalls that catch out sole practitioners
- Treating Part T as a dwellings issue — it is the opposite: dwellings are excluded, small commercial work is in.
- Carrying a pre-2024 shared-facility layout into a new-build café or office scheme and losing a plan check on it.
- Universal toilets drawn as standard cubicles with a basin outside — 'self-contained and fully enclosed' means full-height walls, own basin, own door.
- Forgetting that Part M accessible provision is additional to, not satisfied by, Part T universal toilets in most layouts.
Frequently asked questions
Does Part T apply to houses or flats?
No — dwellings are outside Part T. It applies to new buildings other than dwellings (offices, shops, cafés, community buildings) and certain material changes of use, where toilets are provided for building users. Domestic sanitary provision remains a Part G and Part M matter.
Can a small café provide just one unisex toilet?
Where only a single toilet is provided because of the building's size, a universal toilet — fully enclosed with its own basin — is the compliant form. What Part T rules out in new relevant buildings is mixed-sex cubicle areas sharing circulation and wash spaces. Record the space-constraint reasoning in your tracker.
Track this natively instead of in Word templates
PD Pathway gives small practices an automated Parts A–T relevant-requirements tracker, stage-by-stage Principal Designer checklists and one-click compliance documents — built strictly for non-HRB projects. First project free, then from £10 per project or £99/yr unlimited.