Bathroom electrical zones and IP ratings explained
The closer a fitting is to water, the higher its protection rating has to be.
Lighting is one of the most important parts of a bathroom design — and one of the most regulated.
Key takeaways
BS 7671 divides bathrooms into zones 0, 1 and 2, plus everything outside them.
IP ratings describe protection against solids (first digit) and water (second digit).
Zone 0 needs at least IPX7 and low voltage; zone 1 at least IPX4 (IPX5 for jets); zone 2 at least IPX4.
All bathroom circuits need 30 mA RCD protection.
Most bathroom electrical work is notifiable under Part P and should be done by a registered electrician.
The zones
What the bathroom zones mean
| Zone | Where it is | Minimum rating |
|---|---|---|
| Zone 0 | Inside the bath or shower tray | IPX7, 12 V SELV only |
| Zone 1 | Above the bath or shower up to 2.25 m | IPX4 (IPX5 where jets are used) |
| Zone 2 | 60 cm around zone 1 and the basin, up to 2.25 m | IPX4 |
| Outside zones | The rest of the room | No specific rating; IP44 recommended |
IP ratings
How to read an IP rating
An IP rating has two digits. The first (0–6) covers solid objects and dust; the second (0–8) covers water, from drips to full immersion. IP44 protects against splashes from any direction; IP65 against water jets; IP67 against temporary immersion. An 'X' means the item was not tested for that category.
Design
Lighting a bathroom within the rules
- Downlights over the shower must be suitable for zone 1.
- Lit niches and LED strips in wet areas need the right rating and low-voltage drivers placed safely.
- Illuminated mirrors are usually designed for zone 2.
- Sockets are only allowed at least 3 m from zone 1; shaver points to BS EN 61558-2-5 are the exception.
Lit niches feature in many of our projects, such as A Glow Behind the Glass and Bronze and Brass.
Part P
Part P and who can do the work
New circuits and most work in bathrooms are notifiable. A registered electrician can self-certify and notify building control, giving you a certificate for your records. See also building regulations for bathrooms.
FAQ
Frequently asked questions
IPX4 is the minimum in zones 1 and 2; IP65 is common above showers; IPX7 for anything inside the bath or tray.
Only at least 3 metres from zone 1. Shaver sockets to the correct standard are allowed closer.
Yes for new circuits and most bathroom work, which is notifiable under Part P.
Yes, if they are low voltage, correctly rated and the driver is installed outside the wet zones.
Sources
Sources and further reading
Related services: bathroom design, luxury bathrooms. Related projects: A Glow Behind the Glass, Bronze and Brass, The Long Niche.
