BS 7671 Bathroom Lighting Zones — UK Quick Reference
UK bathroom lighting is governed by BS 7671 (the IET Wiring Regulations, 18th Edition), which divides bathrooms into zones based on proximity to water. Each zone requires a specific minimum IP (Ingress Protection) rating. This quick reference explains the zones, the IP ratings required, and the most common UK installation rules.
Quick Answer
Under BS 7671, UK bathroom lighting requires IPX7 minimum in Zone 0 (inside the bath/shower), IPX4 minimum in Zone 1 (up to 2.25m above the bath rim), and IPX4 minimum in Zone 2 (0.6m outside Zone 1). Outside these zones, no specific IP rating is required, but lights must still be suitable for damp environments. All bathroom electrical work in England and Wales falls under Part P of the Building Regulations.
BS 7671 Bathroom Zones Explained
Zone 0 — Inside the Bath or Shower Tray
Location: Inside the bath itself or inside the shower basin/tray.
Minimum IP rating: IPX7 (protected against temporary immersion).
Voltage: 12V SELV (Separated Extra Low Voltage) only.
Typical fittings: Sealed LED spotlights designed for bath/shower use, pool-style luminaires, underwater LED strips.
Important: Zone 0 installations are rare in domestic bathrooms and should only be carried out by a Part P registered electrician.
Zone 1 — Above the Bath or Shower (up to 2.25m)
Location: The area directly above Zone 0, extending to 2.25 metres above the finished floor level.
Minimum IP rating: IPX4 (protected against splashing water from any direction).
Voltage: 230V permitted if RCD protected, otherwise 12V SELV.
Typical fittings: IP44 or IP65-rated LED downlights, sealed ceiling lights, shower lights.
Zone 2 — 0.6m Outside Zone 1
Location: Extends 0.6 metres horizontally outside Zone 1, up to the same 2.25m height.
Minimum IP rating: IPX4 (splash-protected).
Voltage: 230V permitted with RCD protection.
Typical fittings: Wall lights, mirror lights, IP44 ceiling lights. Many modern bathroom lights are designed for Zone 1/Zone 2 use.
Outside the Zones
Location: Anywhere more than 0.6m from the edge of the bath or shower.
Minimum IP rating: No specific requirement, but fittings should be suitable for damp environments.
Voltage: 230V with standard RCD protection.
Typical fittings: Any standard ceiling light, wall light, or pendant suitable for indoor use. IP20 fittings are acceptable here.
IP Rating Explained
The IP (Ingress Protection) code consists of two digits: the first for solid object protection (dust), the second for water protection. For bathrooms, the second digit is what matters.
| IP Rating | Protection Level | Where to Use |
|---|---|---|
| IP20 | No water protection | Outside bathroom zones only |
| IP44 | Splash-proof from all directions | Zone 1, Zone 2 |
| IP54 | Dust-protected + splash-proof | Zone 1, Zone 2 |
| IP65 | Dust-tight + low-pressure water jets | Zone 1, Zone 2, outdoor |
| IP67 | Dust-tight + temporary immersion | Zone 0, outdoor, ground level |
| IP68 | Dust-tight + permanent immersion | Underwater, pool lighting |
Part P of the Building Regulations
In England and Wales, most electrical work in bathrooms falls under Part P of the Building Regulations. This means the work must either be carried out by a registered electrician (Part P competent) or notified to Building Control before work begins.
Work that must be notified or done by a registered electrician includes:
- Installing new circuits or consumer units
- Replacing a consumer unit
- Any work in a bathroom or wet zone (except like-for-like replacement of existing lighting on an existing circuit)
- Installing electric showers, extractor fans on dedicated circuits, or heated towel rails
Replacing an existing bathroom ceiling light with a new one on the same circuit is generally considered minor work and does not require notification, but the replacement must still meet BS 7671 zone requirements.
Socket Outlets in Bathrooms
Standard 13A socket outlets are not permitted within 3 metres of a bath or shower (except shaver sockets to BS EN 61558-2-5). The only exception is a shaver socket that provides isolation through a built-in transformer.
RCD Protection
All bathroom lighting circuits must be protected by a 30mA RCD (Residual Current Device). Modern consumer units installed since 2016 almost always include RCD protection on all circuits. If your consumer unit is older (pre-2008 with just MCBs and no RCD), you should not install new bathroom lighting without first upgrading the circuit protection.
Common Bathroom Lighting Mistakes
Installing IP20 Fittings in Zone 1 or 2
The most common DIY mistake is using a standard IP20 ceiling light in a bathroom. If the light is within 2.25m above the bath or 0.6m outside that area, it must be minimum IP44. Using lower-rated fittings is a Building Regulations breach and can invalidate home insurance.
Ignoring Shower Cubicle Boundaries
For shower cubicles (without a bath), Zone 1 extends to the full height of the cubicle or 2.25m above the floor, whichever is higher. Many people assume Zone 1 only applies to the ceiling directly above the shower — in fact, wall lights inside the shower cubicle are also Zone 1.
Using the Wrong Transformer for 12V Downlights
Low-voltage 12V LED downlights require a SELV (Separated Extra Low Voltage) transformer that isolates the 12V output from the mains. Standard isolating transformers may not be sufficient for Zone 0 or Zone 1 use.
Relying on Bathroom Downlights Alone
A single row of downlights above a mirror causes harsh shadows under the eyes and chin. For good bathroom lighting, combine overhead lighting with wall-mounted lights at eye level beside the mirror (or an illuminated mirror with integrated LED strips). Both should be IP44 or higher if within Zone 2.
Frequently Asked Questions
What IP rating do I need for a bathroom ceiling light?
For a bathroom ceiling light installed within Zone 1 or Zone 2 (above or within 0.6m of the bath or shower), the minimum IP rating is IP44 (splash-proof). Outside these zones, no specific IP rating is legally required, but IP44 or higher is still recommended for the humid bathroom environment.
Can I install a pendant light above a bath?
Yes, but the fitting must be IP44 or higher and installed no lower than 2.25 metres above the floor. Directly above the bath is Zone 1, which requires splash-proof rating. Most standard pendant lights are IP20 and not suitable for this location.
Is it legal to change a bathroom light myself in the UK?
Replacing a light fitting on an existing circuit with a compliant replacement is classed as minor work and does not require notification to Building Control. However, any new circuits, consumer unit changes, or work that extends the existing installation in a bathroom falls under Part P and must be done by a registered electrician or notified. When in doubt, use a Part P registered electrician.
What is the difference between IP44 and IP65?
IP44 protects against water splashed from any direction (suitable for Zones 1 and 2). IP65 protects against low-pressure water jets from any direction (suitable for direct shower spray areas and outdoor use). For most domestic bathrooms, IP44 is sufficient for ceiling lights outside the direct shower area, while IP65 is recommended inside a walk-in shower enclosure.
Do I need an electrician for bathroom lighting?
For most bathroom lighting work in England and Wales, you need a Part P registered electrician or must notify Building Control. Simple like-for-like replacement of an existing fitting on an existing circuit is generally exempt, but any new wiring, additional fittings, or consumer unit work requires a competent person. Scotland and Northern Ireland have different but broadly similar rules.
Can I use IP rating as my only guide?
IP rating is only one factor. You also need to consider voltage (230V or 12V SELV), whether the circuit is RCD protected, and whether the fitting is specifically designed for bathroom use. Always check the manufacturer's installation instructions and the BS 7671 zone for the specific location.
Shop Bathroom Lighting at Verthara
All Verthara bathroom lights are CE certified, clearly IP rated, and suitable for UK bathroom installations when used in the appropriate zone. Every order includes free UK delivery and a 3-year manufacturer warranty.
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Disclaimer: This guide is for general information only. For any bathroom electrical work beyond like-for-like lamp replacement, consult a Part P registered electrician. Regulations may change — always refer to the latest edition of BS 7671 and Building Regulations Part P for current requirements.