Can I install a socket outlet in a bathroom?

Only shaver supply units with an isolating transformer to BS EN 61558-2-5 are permitted in Zone 2 or outside zones. Standard 13A socket outlets must be located outside all zones, at least 3m from Zone 1. An SELV socket outlet may be installed in Zone 2 provided the safety isolating transformer is located outside Zones 0, 1, and 2.

What zone is a shower over a bath?

The shower head area above the bath is Zone 1, extending up to 2.25m from the finished floor level. Zone 0 is inside the bath itself (below the rim). The 0.6m horizontal area measured outward from the bath perimeter at Zone 1 height is Zone 2.

Can I use a pull cord switch in a bathroom?

Yes. Ceiling-mounted pull cord switches can be installed in Zone 1 or Zone 2 provided they have a suitable IP rating for the zone — minimum IPX4 in Zones 1 and 2. They must be rated for the connected load and installed at a height that keeps the mechanism above Zone 1 (2.25m).

Do downlights in a bathroom need to be IP rated?

If positioned directly above the bath or shower (Zone 1), downlights need a minimum IP rating of IPX4. Above Zone 2, they also require IPX4. If located outside all zones (for example, in the centre of a large bathroom away from the bath), standard IP20 is acceptable, although IPX4 is recommended as good practice due to the humid environment.

What cable can be used in bathroom zones?

PVC sheathed Twin & Earth (T&E) cable can be installed in all bathroom zones. Wiring systems must be suitable for the conditions present. Cables should not cross through zones unnecessarily, and where they run within zones, they should be installed at a height above Zone 1 (above 2.25m) where practical, per Regulation 701.512.3.

Do I need Part P sign-off for bathroom electrics?

Yes. New electrical work in bathrooms is notifiable under Part P of the Building Regulations (England and Wales). This includes new circuits, replacement consumer units affecting bathroom circuits, and installing new fixed equipment such as showers, fans, or heated towel rails. Work must be carried out by a registered competent person scheme member or inspected by Building Control.

Bathroom Electrical Zones Guide

Complete guide to bathroom electrical zones 0, 1, and 2 under BS 7671 Section 701, including IP ratings, equipment selection, and installation requirements.

BS 7671Section 70118th Edition

What Are Bathroom Electrical Zones?

BS 7671 Section 701 divides bathrooms and shower rooms into defined zones that determine what electrical equipment can be installed and the IP ratings required. Understanding these zones is essential for any electrical work in a bathroom.

Bathroom zone definitions

BS 7671 Regulation 701.32

Zone	Boundary Definition	Height
Zone 0	Interior of the bath tub or shower tray	Up to the top of the bath rim or shower tray
Zone 1	Directly above Zone 0	From Zone 0 up to 2.25m from the finished floor level
Zone 2	0.6m horizontally beyond Zone 1	Up to 2.25m from the finished floor level
Outside zones	Beyond Zone 2 in all directions	Above 2.25m everywhere, and beyond 0.6m from Zone 1

Where there is no bath tray or shower tray, Zone 0 is the floor area beneath the shower head to a depth of 0.05m and Zone 1 extends 1.2m from the water outlet.

Shower Without a Tray

For walk-in showers or wet rooms without a defined shower tray, the zone boundaries are measured differently. Zone 1 extends 1.2m horizontally from the fixed water outlet (shower head position), and Zone 0 is the floor area to a depth of 0.05m below the lowest water outlet.

What IP Ratings Are Required in Each Zone?

IP (Ingress Protection) ratings define how well equipment resists water ingress. Each bathroom zone has minimum IP rating requirements to prevent electric shock.

Minimum IP ratings by bathroom zone

BS 7671 Section 701 and BS EN 60529

Zone	Minimum IP Rating	Protection Level	Notes
Zone 0	IPX7	Protection against temporary immersion	Equipment must withstand submersion to 1m for 30 minutes
Zone 1	IPX4	Protection against splashing from any direction	IPX5 required where water jets are used for cleaning (e.g., communal showers)
Zone 2	IPX4	Protection against splashing from any direction	Same as Zone 1 for splash resistance
Outside zones	General	No specific minimum for water ingress	Consider splash risk — IPX4 recommended in humid bathrooms

IP ratings comprise two digits: the first for solid object protection, the second (after 'X') for water protection.

IPX5 for Communal Areas

Where water jets are used for cleaning purposes (such as in communal showers, changing rooms, or swimming pool areas), the minimum IP rating in Zone 1 increases from IPX4 to IPX5 — protection against jets of water from any direction.

What Electrical Equipment Can I Install in Each Zone?

Each zone restricts the type of electrical equipment that can be installed. The closer to the water source, the more restrictive the requirements.

Permitted equipment by zone

BS 7671 Regulation 701.55 and 701.512.3

Zone	Permitted Equipment	Voltage / Supply	Key Restrictions
Zone 0	Fixed SELV equipment only (e.g., chromotherapy lights)	12V AC / 30V DC SELV maximum	Safety isolating transformer must be outside Zones 0, 1, and 2
Zone 1	SELV devices, fixed water heaters, electric showers, shower pumps (IPX4+)	SELV or 230V for fixed current-using equipment	No switchgear except SELV switches; no socket outlets
Zone 2	All Zone 1 items plus luminaires, fans, shaver sockets (BS EN 61558-2-5), heated towel rails	230V with 30mA RCD protection	Shaver sockets must have isolating transformer
Outside zones	Most equipment permitted with appropriate IP rating	230V with 30mA RCD protection	Standard 13A sockets must be 3m+ from Zone 1

Electric Shower Installation

Electric showers in Zone 1 must be a fixed, permanently connected appliance — not plug-in. The unit must have a suitable IP rating (minimum IPX4) and be supplied by a dedicated circuit with 30mA RCD protection. The isolator switch should be accessible from outside the bathroom or be a ceiling-mounted pull cord.

Do Bathrooms Need RCD Protection?

RCD protection is mandatory for all circuits serving a bathroom or shower room, regardless of which zone the equipment is installed in.

Regulation 701.411.3.3 requires that every circuit serving a location containing a bath or shower is protected by a 30mA RCD. This applies to all circuits — lighting, power, heating, and ventilation — not just those with accessories within the zones. There are no exceptions for fixed equipment.

RCD protection requirements for bathrooms

BS 7671 Regulation 701.411.3.3

Circuit Type	RCD Required	Rating	Notes
Lighting	Yes	30mA	Including circuits outside zones
Electric shower	Yes	30mA	Dedicated circuit required
Heated towel rail	Yes	30mA	Fused connection unit or RCBO
Extractor fan	Yes	30mA	Often on lighting circuit
Shaver socket	Yes	30mA	Isolating transformer provides additional protection
Underfloor heating	Yes	30mA	Electric UFH in bathroom zones

Circuits that merely pass through the bathroom (e.g., to another room) also require 30mA RCD protection.

No Exceptions

Unlike some other special locations, there is no exemption from RCD protection for fixed equipment in bathrooms. Even a dedicated cooker-type circuit for a towel rail must have 30mA RCD protection when it serves a bathroom location.

Is Supplementary Bonding Still Required in Bathrooms?

Amendment 2 of BS 7671 introduced conditions under which supplementary bonding in bathrooms can be omitted, but the requirements must be carefully verified.

Under Regulation 701.415.2, supplementary bonding within a bathroom can be omitted where all of the following conditions are satisfied:

Conditions for omitting supplementary bonding

BS 7671 Regulation 701.415.2

Condition	Requirement	How to Verify
RCD protection	All circuits in the bathroom have 30mA RCD protection	Check consumer unit — all bathroom circuits on RCD/RCBO
Disconnection times	Automatic disconnection times per Regulation 411.3.2 are met	Verify Zs values are within limits for all circuits
Main bonding	All extraneous-conductive-parts are connected to main protective bonding	Confirm bonding to gas, water, and any other metallic services

When in Doubt, Bond

If you cannot verify that all three conditions are met — for example, if Zs values are marginal or the installation is old and the main bonding is uncertain — install supplementary bonding. The cost of bonding conductors is negligible compared to the safety risk. Use 4mm² copper between simultaneously accessible exposed and extraneous conductive parts.

What Are the Key BS 7671 Regulations for Bathrooms?

A quick reference to the most important regulation numbers you need when designing or inspecting bathroom electrical installations.

Key BS 7671 bathroom regulations

BS 7671:2018+A2:2022 Section 701

Regulation	Subject	Summary
701.1	Scope	Applies to all rooms containing a bath or shower, including shower rooms without a bath
701.32	Classification of zones	Defines Zones 0, 1, and 2 boundaries and dimensions
701.411.3.3	RCD protection	30mA RCD required for all circuits serving the bathroom location
701.415.2	Supplementary bonding	Conditions under which supplementary bonding may be omitted
701.512.3	Wiring systems	Cable installation requirements within zones — routing and concealment
701.55	Other equipment	Restrictions on switchgear, socket outlets, and accessories by zone

Always refer to the full regulation text. This table provides a summary for quick reference only.

EICR Inspections — Bathroom Checklist

When carrying out an EICR in a bathroom, check: zone classification is correct, all circuits have 30mA RCD protection, equipment IP ratings match the zone, supplementary bonding is present (or conditions for omission are met), and all accessories are suitable for the environment. Missing RCD protection on bathroom circuits is typically coded C2.

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