Bathroom Zones Explained: What Can Go Where in a UK Bathroom

Bathroom zones are areas around the bath and shower, defined in the IET Wiring Regulations (BS 7671), that set which electrical fittings can go where and how water-resistant they must be. Zone 0 is inside the bath or shower tray, zone 1 is the space directly above it up to 2.25m, and zone 2 extends 0.6m beyond zone 1. Anything further away is outside the zones, though the whole room still has extra rules.

The zones only matter because water and electricity don't mix. They decide the IP rating a light needs, where a fan can sit and why there's no ordinary socket next to the basin, and our bathroom fitting in Kettering team plans every electrical position around them before the first pipe is moved.

Zone 0: inside the bath or shower

Zone 0 is the interior of the bath or shower tray, the part that can hold water. In a wet room or level-access shower, it covers the shower floor area where water collects.

Only equipment designed to be submerged can go here. It must be rated at least IPX7 and run at extra-low voltage, typically 12V, with the transformer or power supply located outside the zones. In practice, very little goes in zone 0 in a home bathroom beyond specialist bath lighting.

Zone 1: directly above the bath or shower

Zone 1 is the space above zone 0, up to a height of 2.25m from the floor (or higher if the fixed shower head is higher). It follows the footprint of the bath or tray straight up.

Fittings here must be rated at least IPX4, and IPX5 where water jets are likely to be used, for example for cleaning. Typical zone 1 items are:

• Shower-rated downlights in the ceiling above the shower, where the ceiling falls within the zone

• An electric shower unit, which is designed for this position

• An extractor fan rated for the zone, where it sits above the shower

Zone 2: the area around the bath or shower

Zone 2 extends 0.6m horizontally beyond the edge of zone 1, and up to 2.25m high. In a small bathroom, zone 2 often takes in the basin area and the space next to the toilet.

Fittings in zone 2 must be rated at least IPX4. A shaver supply unit (the specific socket for razors and toothbrushes, built to its own safety standard) can go in zone 2 as long as it is out of the reach of direct shower spray.

Outside the zones

Beyond zone 2, there are no zone-specific IP ratings. A bathroom is still classed as a special location, though, so some rules apply across the whole room:

• Sockets: standard socket outlets must be at least 2.5m horizontally from the edge of zone 1. In most UK bathrooms that rules them out entirely, which is why a shaver unit is the usual answer.

• RCD protection: all circuits serving the bathroom must be protected by a 30mA residual current device.

• Switches: light switches are usually outside the room or a ceiling pull cord inside it, so no one touches a wall switch with wet hands.

Bathroom lighting by zone

Lighting is where zones affect most bathroom designs. A simple way to plan it:

• Over the shower or bath: IPX4 or better (IPX5 if jets could reach it). Low-voltage, shower-rated downlights are common.

• Over the basin and mirror: check whether it falls in zone 2. If it does, IPX4 minimum. Illuminated mirrors are normally sold with the rating stated.

• General ceiling lights away from the bath and shower: outside the zones, although many people choose IP-rated fittings anyway because of steam.

Heated towel rails, underfloor heating and extractor fans all follow the same logic: check the zone, then check the fitting's IP rating and the manufacturer's installation instructions.

Who can do bathroom electrical work?

Electrical work in a bathroom must be done to BS 7671 and signed off. In England, building regulations Part P covers electrical safety in homes, and the simplest route is a registered electrician in a government-approved competent person scheme, who can self-certify the work and issue the certificate.

When we fit a bathroom, the electrical side is carried out and certified by a registered electrician as part of the job. Keep the certificate. Buyers' solicitors ask for it when you sell, and it's part of what makes a new bathroom count in how much value a new bathroom adds.

Zones and bathroom layout

Zones follow the bath and shower, not the room. Moving a shower changes where zone 1 and zone 2 sit, which can move the fan, the lighting positions and the shaver point. That's why lighting and electrics are planned with the layout, before first fix, not after the tiles are up. The same thinking applies to a new en suite, where the room is small and the zones take up much of it.

Bathroom zone questions, answered

Is there still a zone 3?

No. Older wiring regulations had a zone 3, but it was removed from BS 7671 in 2008. Anything beyond zone 2 is now simply outside the zones.

Can I have a normal socket in a bathroom?

Only if it is at least 2.5m horizontally from zone 1, which few UK bathrooms allow. A shaver supply unit is the standard alternative.

Does a light outside the zones need an IP rating?

The regulations don't require one outside the zones, but steam and condensation reach the whole room, so a rated fitting is a sensible choice.

Our own team designs and fits bathrooms across Kettering and Northamptonshire, including bathroom fitting in Northampton, and every electrical item is placed to suit its zone and certified by a registered electrician. You can see one of our finished rooms in our bathroom fitting project in Corby.