BS 7671 Section 701
Bathroom electrical zones
Bathrooms and rooms containing a bath or shower are treated as special locations under BS 7671. Section 701 splits them into Zone 0, Zone 1 and Zone 2 — each with its own minimum IP rating and list of accessories that may be installed. Everything below is a plain-English summary; the wiring regs remain the authoritative document.
Zone 0
Inside the bath tub or shower tray itself.
- Minimum IP
- IP X7 (immersion)
- Allowed
- Only fixed, permanently connected equipment made for Zone 0, supplied by SELV at no more than 12 V AC or 30 V ripple-free DC, with the safety source outside the zones (Reg 701.55). Mains-voltage (230 V) equipment is not permitted.
- Not allowed
- Sockets, switches, mains-voltage accessories of any kind.
Zone 1
Above the bath/shower tray up to 2.25 m from the floor (or above the fixed shower head if higher).
- Minimum IP
- IP X4 (splash) — IP X5 if a water jet is likely (public showers).
- Allowed
- Fixed luminaires, fans and electric showers rated for Zone 1, supplied through a 30 mA RCD.
- Not allowed
- Socket-outlets of any kind, including shaver supply units.
Zone 2
0.6 m horizontally outside Zone 1, up to 2.25 m from the floor. Wash basins do not create a zone of their own under the 18th Edition.
- Minimum IP
- IP X4 minimum.
- Allowed
- Luminaires and fans rated IP X4+; shaver supply units to BS EN 61558-2-5 permitted where direct spray is unlikely.
- Not allowed
- General 13 A socket-outlets.
Outside the zones
Everywhere else in the room.
- Minimum IP
- Normal indoor rating (usually IP 20).
- Allowed
- Standard accessories are permitted. 230 V socket-outlets must be at least 3 m horizontally from the edge of Zone 1 (Reg 701.512.3), and every circuit serving the location requires 30 mA RCD protection (Reg 701.411.3.3).
- Not allowed
- —
Rules that apply to the whole room
- 30 mA RCD on every circuit serving the location — lighting, shower, towel rail, fan and any spur — Reg 701.411.3.3.
- Supplementary bonding is only required where the general RCD/main bonding conditions of Reg 701.415.2 are not all met. In most modern installations with 30 mA RCDs and effective main bonding, supplementary bonding can be omitted.
- Shaver sockets to BS EN 61558-2-5 (isolating transformer built in) are the only socket-type accessory permitted inside Zones 1 and 2.
- Pull-cord switches are the traditional in-room switch; standard rocker switches must be located outside the zones (usually just outside the door).
Adding a shaver socket, fan or downlights?
Paul can specify the correct IP rating, RCD protection and cable route for any bathroom addition, and self-certify the work under NAPIT so no separate building control notification is needed.