Bathroom Electrics: IP Zones, Electric Showers, Shaver Sockets, and the Section 701 Rules
Bathrooms are the most regulated electrical environment in a domestic property. This guide explains the zone system, what you can and cannot install where, and what all bathroom electrical work in 2026 must comply with.
Dan Stevens
NAPIT Registered Electrician
The Zone System: Zones 0, 1 and 2
BS 7671:2018+A2 Section 701 defines three zones in bathrooms and shower rooms. Each zone has minimum IP (Ingress Protection) requirements for electrical equipment:
| Zone | Location | Min. IP Rating | What's Permitted |
|---|---|---|---|
| Zone 0 | Inside the bath or shower tray | IPX7 | SELV equipment only (12V max). Purpose-built waterproof speakers, LED strips rated IPX7. |
| Zone 1 | Above bath/shower tray to 2.25m; the shower area including enclosure | IPX4 | IPX4-rated luminaires, electric showers (fixed permanently wired), SELV equipment. |
| Zone 2 | 600mm horizontally from Zone 1; above bath outside Zone 1 | IPX4 | IPX4 luminaires, shaver sockets (BS EN 61558-2-5), heated towel rails. |
Outside all three zones — typically the wall area more than 600mm from any water source — standard electrical accessories are permitted, provided they are RCD-protected. No standard 13A socket outlets are permitted inside Zones 0, 1 or 2 under any circumstances.
Electric Shower Wiring
An electric shower requires a dedicated radial circuit from the consumer unit — it cannot share a circuit with other loads. Typical specifications:
- 7.5–8.5kW shower: 6mm² cable, 40A RCBO at the consumer unit, 45A double-pole pull-cord switch within the bathroom
- 9.5–10.5kW shower: 10mm² cable, 45A or 50A RCBO, 50A double-pole isolator switch
- Over 10.5kW: 10mm² cable minimum, 50A RCBO — check the shower's installation manual for exact rating
The pull-cord switch or double-pole isolator must be positioned outside Zone 1 and out of reach of a person using the shower. The shower unit itself is a Zone 1 appliance and must carry at minimum an IPX4 rating — most modern electric showers are IPX5.
Supplementary bonding: since the 17th Edition Amendment 1 (2011), supplementary equipotential bonding within the bathroom is not required if the main protective bonding to the property's water and gas pipes is in place and all circuits in the bathroom are RCD-protected. If the main bonding is absent or old circuits without RCD protection are present, supplementary bonding of all exposed metalwork (bath taps, pipework) is still required.
Shaver Sockets
A shaver socket is the only socket outlet permitted inside a bathroom. It must be a BS EN 61558-2-5 shaver supply unit incorporating an isolating transformer — this limits fault current and provides galvanic isolation from the mains. Standard 13A sockets are not permitted anywhere in Zones 0, 1 or 2.
Shaver sockets are Zone 2 accessories and must be positioned at least 600mm horizontally from the bath or shower. Like-for-like replacement of an existing shaver socket is not notifiable under Part P. Installing a new one requires a Part P registered electrician.
Heated Towel Rails
Electric heated towel rails are wired via a fused connection unit (FCU) — they must not have a standard plug and socket. The FCU is typically positioned outside Zone 1, with the flex to the towel rail entering Zone 2 or Zone 1 if the towel rail is inside those zones.
Options for switching a heated towel rail:
- Unswitched FCU — towel rail is always live (common for bathrooms without a time-controlled bathroom circuit)
- Switched FCU outside the bathroom — switch on the landing or outside the door; FCU inside feeds the towel rail
- Pull-cord switch in the bathroom — double-pole pull-cord switch (not rocker-type) positioned outside Zone 1
- Thermostat or timer — the towel rail's own built-in thermostat controls temperature; external timer at the consumer unit or spur controls on/off
Bathroom Lighting Rules
All bathroom lighting must comply with the zone IP requirements above. Practical guidance:
- Ceiling roses with pendant bulbs are not suitable — use sealed IP-rated fittings
- LED downlights directly above a bath or shower must be IPX4 minimum (Zone 1). Fire-rated downlights with IPX4 ratings are widely available
- Bathroom light switches must be pull-cord type if inside the bathroom, or a standard rocker switch outside the room
- All bathroom lighting circuits must be RCD-protected (32mA or 30mA RCD or RCBO at the consumer unit)
Part P: What Needs to Be Notified
All of the following require a Part P registered electrician or Building Control notification:
- Installing a new electric shower circuit
- Adding any new circuit in a bathroom (towel rail, additional lighting circuit)
- Installing a new shaver socket where no socket existed before
- Any rewiring within a bathroom
The following are not notifiable (like-for-like replacements):
- Replacing an existing light fitting with one of the same type on the same circuit
- Replacing an existing shaver socket like-for-like
- Replacing an existing pull-cord switch like-for-like
Bathroom Electrics Costs in Somerset 2026
Electric Shower (new circuit)
from £280
Shaver Socket
from £80
Towel Rail Wiring
from £120
Bathroom Lighting Circuit
from £180
Indicative prices ex VAT. Actual cost depends on access, cable runs, and consumer unit capacity. Call for a firm quote.
Bathroom Electrical Work in Somerset
DS Electrical carries out all bathroom electrical work to BS 7671 Section 701, with full Part P notification and completion certificate. Electric showers, towel rails, shaver sockets, IP-rated lighting — all covered across Wells, Bath, Shepton Mallet, Frome and surrounding Somerset.