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Bathroom Zones UK: What Each Zone Covers, the IP Ratings and What You Can Fit Where

Bathroom zones in the UK are set by Section 701 of BS 7671, the IET Wiring Regulations, and they decide every light, fan, shaver point and towel rail in a bathroom design. Zone 0 is the inside of the bath or shower tray. Zone 1 is the space above it up to 2.25m from the floor. Zone 2 runs a further 0.6m out. A standard 230V socket must sit at least 2.5m from the edge of zone 1. This page sets out each zone, the IP rating it needs, what can go in it, how walk-in showers change the picture, and when the work has to be notified under Part P.

Where the bathroom zone rules come from

The zones are defined in Section 701 of BS 7671, "Locations containing a bath or shower". BS 7671 is the British Standard that electricians work to, and Building Regulations Part P expects electrical work in homes to meet it. The zones are measured from the bath or shower tray, the fixed shower head and the finished floor, so they move when the layout moves. That is why they matter at the design stage: shifting a basin or shower by half a metre can decide whether a mirror light, a towel rail or a shaver point is allowed where you want it.

Zone 0: inside the bath or shower tray

Zone 0 is the space inside the bath or shower tray, the volume that holds water. Anything fitted here has to be rated at least IPX7, which means it can survive temporary immersion, and it must run at separated extra-low voltage (SELV) of no more than 12V AC or 30V ripple-free DC, with the power supply sited outside the zones. In practice that means purpose-made low-voltage bath lights and little else.

Zone 1: above the bath or tray, to 2.25m

Zone 1 is the space directly above zone 0, up to 2.25m above the floor. If the fixed shower head or another water outlet is higher than 2.25m, zone 1 rises to that height. The space under the bath also counts as zone 1, unless the bath panel can only be removed with a tool such as a screwdriver; a clip-on panel you can pull off by hand does not take the space out of the zone.

Only fixed, permanently connected equipment designed for the position can go in zone 1, and it must be at least IPX4, protected against splashing. That list includes electric showers, shower pumps, extractor fans, heated towel rails, water heaters, whirlpool bath units and suitably rated light fittings, plus SELV or PELV equipment at up to 25V AC or 60V DC. Where equipment may be hit by water jets, for example during cleaning, it needs IPX5.

Zone 2: the 0.6m band around zone 1

Zone 2 extends 0.6m horizontally beyond the edge of zone 1 and up to the same 2.25m height. It typically catches the area beside the bath where you step out, and often a basin or WC placed close to it. Equipment here also needs at least IPX4. What zone 2 rules out is 230V switchgear and socket-outlets. The exceptions are SELV supplies and shaver supply units made to BS EN 61558-2-5, which are allowed in zone 2 but never in zones 0 or 1.

Outside the zones, and the 2.5m socket rule

Beyond zone 2 the regulations relax, but they do not disappear. Standard 230V socket-outlets are allowed in a room with a bath or shower only if they are at least 2.5m horizontally from the boundary of zone 1. That figure came in with Amendment 2 to the 18th Edition in 2022; before that it was 3m, and some older guidance online still quotes 3m. In most British bathrooms, which are rarely that big, the result is the same: no ordinary sockets. Our socket height guide covers the separate rules on how high sockets sit elsewhere in the home.

Two rules apply to the whole room, whatever the zone. Every circuit serving the bathroom, or passing through zones 1 or 2, needs 30mA RCD protection, with the exception of SELV circuits. And a ceiling pull-cord switch is fine: the cord can hang into zone 1, provided the switch body itself is sited correctly.

Walk-in showers and wet rooms

Showers without a tray work differently. With no basin to measure from, zone 1 is set by the shower head: it extends 1.2m horizontally from the centre of the fixed water outlet, and there is no separate zone 2 in that arrangement. For a wet room or a walk-in shower, that 1.2m radius often covers a good part of the room, which is why lighting and heating in wet rooms tend to be IPX4 or better throughout. Our wet room regulations guide covers the waterproofing and drainage side.

IP ratings in plain English

The X in an IP rating stands in for the dust protection figure, which the bathroom zones do not specify. Designers often choose IP44 or IP65 downlights for the whole bathroom ceiling anyway, so that a later change of layout does not leave a fitting in the wrong zone.

Supplementary bonding

Older bathrooms often have green and yellow earth cables clamped to pipes and the bath. Under Regulation 701.415.2, that supplementary bonding can be left out of a new installation if every circuit in the room has 30mA RCD protection, all the final circuits meet the automatic disconnection requirements, and the metal pipework and other extraneous-conductive parts are connected to the main protective bonding. Your electrician decides this on site and records it on the certificate; do not remove existing bonding yourself.

Is bathroom electrical work notifiable under Part P?

In England, Approved Document P makes three kinds of work notifiable: a new circuit, a replacement consumer unit, and any addition or alteration to existing circuits in a special location, which includes the space around a bath or shower. Swapping a light fitting or a fan like for like is not notifiable. Most bathroom refits involve moving or adding something, so in practice they are usually notifiable, and the simplest route is to use an electrician registered with a competent person scheme, who self-certifies the work. Our Part P guide explains the schemes and what you should receive at the end, and our extractor fan regulations guide covers the ventilation rates a bathroom needs.

Designing around the zones

• Plan the layout first, then the electrics. Zones are measured from the bath, tray and shower head, so fix those before choosing lights.
• Put mirror cabinets and shaver points outside zone 1. A shaver supply unit can go in zone 2; a standard socket cannot go in the room at all unless it is 2.5m clear.
• Specify IP-rated fittings throughout if the room is small or the shower is a walk-in.
• Use a heated towel rail designed for bathrooms and have it hard-wired through a fused spur outside the zones.

For layout ideas, see our guide to designing a bathroom and our minimum bathroom size guide, or go back to the Vertigo Interiors home page.

Sources

• Sparky Safety, bathroom zones under BS 7671 Amendment 2: sparkysafety.co.uk
• GOV.UK, Approved Document P: electrical safety in dwellings: gov.uk

Checked on 1 October 2026.