The bathroom is the one room where lighting stops being purely a matter of taste and becomes a matter of regulation. Water and electricity have never got on, so the wiring regulations split every bathroom into zones, and every fitting carries an IP rating that says how well it keeps water out. Match the rating to the zone and you can be as stylish as you like. Get it wrong and your electrician will, quite rightly, refuse to fit it.
The zones are set out in BS 7671, the UK wiring regulations (currently the 18th edition). Here’s the whole system in plain English.
The bathroom zones: a map of how wet things get
- Zone 0 is inside the bath or shower tray itself. Fully submersible territory.
- Zone 1 is directly above the bath or shower, up to 2.25m from the floor. Spray and steam central.
- Zone 2 is a 0.6m band around Zone 1, plus the area around the basin. Splash range.
- Outside the zones (older guidance called this Zone 3) is everywhere else in the room. Still steamy, but no direct water.
The IP rating: how waterproof a fitting is
IP stands for Ingress Protection. Every fitting has an IP number, like IP44 or IP65. The first digit is dust protection and the second is water protection, so IP65 means fully dust-tight and protected against water jets. For bathrooms, the second digit is the one that matters most. Here’s what each zone needs:
| Zone | Minimum IP rating | In practice |
|---|---|---|
| Zone 0 (inside bath/shower) | IP67, 12V max | Specialist low-voltage fittings only |
| Zone 1 (above bath/shower) | IP65 | Shower-rated downlights |
| Zone 2 (around bath/basin) | IP44 | IP44 wall lights, mirror lights |
| Outside the zones | No formal minimum | Any fitting, though IP44 is wise in a steamy room |
Now the fun part: lighting it well
The rules tell you what’s safe. They don’t tell you what’s flattering. Most bathrooms get one ceiling light and a shaving light, then leave you wondering why the room feels like a lift. The same three-layer thinking we use in kitchens works here too.
Ambient
Two to four IP-rated downlights, dimmable, at 3000K. Warmer than you’d expect. Bathrooms photographed in showrooms are almost never lit cool, whatever the magazines imply. Use our downlight spacing guide to work out the number.
Task: the mirror matters most
The most important light in any bathroom is the one on your face at the mirror, and a downlight above your head is the worst possible choice, throwing every shadow you don’t want at 7am. The gold standard is vertical light on either side of the mirror, from IP44 wall lights or an illuminated mirror with side panels. You’ll look better and shave or do your makeup more accurately. This one change transforms a bathroom.
Accent
LED strip under a floating vanity, a niche light in the shower, or a low-level plinth washer for a midnight-friendly glow. All available IP65-rated, and all cheaper than they look.
Three quick extras worth knowing
- Switches must be outside the room, or ceiling-mounted pull cords inside. Smart bulbs and app control sidestep this neatly.
- Extractor fans follow the same zone rules. In Zone 1 they need to be low-voltage or suitably rated and RCD-protected.
- Certification. Bathroom electrical work is notifiable under Part P of the Building Regulations in England and Wales. Use an installer registered with a competent person scheme and keep the certificate, because you’ll need it when you sell the house. Every installer on the Luxwell network qualifies, and we arrange them as part of the purchase.
See the zones drawn on a real ceiling
The bathroom room set in each of our showrooms has the zones marked out overhead, with every fitting labelled by IP rating, so the whole regulation is visible at a glance. Ten minutes in there beats an afternoon of forum threads. Find your nearest on the contact page.
