Which zone, and what that means you can fit
A bathroom is the only room in a British house where the position of a light fitting is regulated. BS 7671 Section 701 divides the room into zones by distance from the bath or shower, and each zone sets a minimum ingress protection rating. Get it wrong and the installation is non-compliant, the electrician won't certify it, and your insurer has a question to ask.
This page explains the zones in plain English, tells you what rating you need in each, and covers the parts nobody mentions until it is too late: fire rating, Part P notification, and why the fitting above your basin probably needs a higher CRI than the one above your bath.
1. The zones
| Zone | Where it is | Minimum rating |
|---|---|---|
| Zone 0 | Inside the bath itself, or inside the shower tray. Anywhere water will actually sit. | IP67, and SELV at 12V maximum |
| Zone 1 | Directly above zone 0, up to 2.25m from the finished floor. The ceiling above a bath or shower is zone 1 if the ceiling is 2.25m or lower. | IP65 in practice (IP44 is the Regulations' minimum, but anywhere a shower head can reach should be IP65) |
| Zone 2 | A 600mm band beyond zone 1 in every direction, and the 600mm radius around a basin tap. | IP44 |
| Outside the zones | Everywhere else in the room. | No IP minimum under Section 701, though IP44 is sensible in a room that gets steamy |
Two things people get wrong. First, a ceiling higher than 2.25m above a bath is not zone 1 — but the area directly above the bath up to 2.25m still is, so a pendant hanging into that space must be rated for it. Second, the 600mm around a basin tap is zone 2, which catches a great many over-mirror lights and wall lights that people assume are in the clear.
2. What the IP number actually means
Two digits. The first is protection against solids, the second against water.
| Rating | Protected against | Use it |
|---|---|---|
| IP20 | Fingers. Nothing else. No water protection at all. | Never in a bathroom zone. Fine in a cloakroom with no bath or shower. |
| IP44 | Splashing water from any direction | Zone 2 and outside the zones |
| IP65 | Low-pressure jets of water from any direction | Zone 1, and anywhere a shower head can reach |
| IP67 | Temporary immersion in water up to 1m | Zone 0 only, with SELV at 12V |
| IP68 | Continuous immersion | Usually connectors and joints rather than fittings |
There is no such thing as a partial rating. A fitting is either tested to IP65 or it is not, and "suitable for bathrooms" on a marketplace listing means nothing on its own. If a listing doesn't state a number, assume IP20.
3. Fire rating — a separate question from IP
Cutting a hole in a ceiling makes a hole in a fire barrier. If there is a habitable room, a loft or a flat above, a downlight in that ceiling should be fire rated to BS 476 Part 21 — typically 30, 60 or 90 minutes, matched to the floor construction above.
Fire rating and IP rating are independent. A fitting can be IP65 and not fire rated, or fire rated and only IP20. A bathroom downlight in a ceiling with a room above needs both. Where a fitting is not fire rated, a fire hood fitted above it in the ceiling void is the usual remedy — we sell those on the fixings and seals page.
Two more properties worth checking on a downlight: airtight (stops warm damp air being pumped into the loft, which matters more in a bathroom than anywhere) and acoustic (maintains the sound separation between flats).
4. Light quality, and why a bathroom is the hardest room to get right
The bathroom is where people examine their own face at close range. Two numbers decide whether that goes well.
- CRI — colour rendering index, how truthfully a light source shows colour against daylight. Cheap LED sits at CRI 80, which makes skin look grey and makes it genuinely difficult to shave, apply make-up or spot a rash. CRI 95 and above is the threshold where skin looks like skin. Everything in our CRI 95 and above collection meets it.
- Colour temperature — 2700K is warm and domestic, 3000K is a good general bathroom, 4000K is clinical and unforgiving. Mixing temperatures in one room is the single most common mistake in a bathroom scheme. Pick one, or buy tunable fittings and change the whole room together.
5. Where to put the light, not just what to buy
- Never light a face from directly overhead. A downlight above the basin throws every shadow downward — eye sockets, under the nose, under the chin. It is the least flattering and least useful place to put light in the whole room.
- Light the face from the sides. A vertical pair either side of the mirror, or a front-lit mirror, puts light on the face rather than on the top of the head. This is the single biggest improvement most bathrooms can make.
- A backlit mirror does not light your face. It lights the wall behind it and looks beautiful doing so. Treat it as mood lighting and add a separate task light. We put the lux figures side by side on front lit or backlit.
- Downlights: 4 in a typical 2.2 × 1.8m bathroom, spaced about 1m apart and roughly 600–800mm off the walls. Six is usually too many and creates a grid of scallops.
- Put lighting on more than one circuit. Downlights on one, mirror light on another, and ideally an amber night circuit at low level for 3am. That last one is the detail people thank us for.
6. Part P, certificates and who may do the work
In England and Wales, electrical work in a room containing a bath or shower is notifiable under Part P of the Building Regulations, as are a new circuit or a consumer unit replacement anywhere in the dwelling. In practice that means adding, moving or altering a light or a shaver socket in a bathroom is notifiable work — a straight like-for-like replacement of an existing fitting generally is not.
Notifiable work must either be carried out by an electrician registered with a competent person scheme (NICEIC, NAPIT, ELECSA and others), who self-certifies and issues the certificate, or be notified to your local authority building control before it starts. Scotland and Northern Ireland run their own building standards systems with different rules.
You should receive an Electrical Installation Certificate or a Minor Electrical Installation Works Certificate on completion, plus a Building Regulations compliance certificate for notifiable work. Keep them: you will be asked for them when you sell the house.
If you'd rather not organise any of that, our Fitted By Us packages are supplied and installed by a registered electrician with the notification and certificates included.
7. Extract, because light isn't the only thing the room needs
Approved Document F sets minimum extract rates: 15 litres per second for a bathroom, 6 l/s for a WC-only room. A humidity-sensing or continuously-running fan will do more for the life of your paint, your grout and your fittings than any other single purchase. Our extractor fans with lighting all state their rate.
Not sure?
Send us the room dimensions, the ceiling height, where the bath or shower is and what's above the ceiling, and we'll tell you what's allowed where and how many fittings you need. support@homartuk.com · 07868 375682.
This page is general guidance written to help you buy the right product. It is not a substitute for the judgement of a qualified electrician, and it is not a design for your installation. Always have bathroom electrical work carried out by a competent person.