Bathroom Electrics: IP Zones, Electric Showers, Shaver Sockets, and the Section 701 Rules

The Zone System: Zones 0, 1 and 2

BS 7671:2018+A4:2026 Section 701 defines three zones in bathrooms and shower rooms. Each zone has minimum IP (Ingress Protection) requirements for electrical equipment:

Outside the zones, other electrical accessories are permitted provided they are RCD-protected, but ordinary 230 V sockets must still be at least 2.5 m horizontally from the edge of zone 1. 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 close to the bath or shower is notifiable under Part P.

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
• Every circuit serving the bathroom must be protected by a 30mA RCD (RCD or RCBO at the consumer unit)

Part P: What Needs to Be Notified

All of the following are notifiable under Part P (a registered installer who self-certifies, a registered third-party certifier, or a building control notice before work starts):

• 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 addition or alteration to circuits close to the bath or shower

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

How We Price Bathroom Electrics in Mid Somerset

We don't publish a price list for bathroom work, because no two bathrooms are the same. The price depends on the access, the cable runs and how much capacity your consumer unit has, as well as what you are adding. We look at the job first, then give you a fixed written quote. Ask for a quote.

Frequently Asked Questions