Bathrooms are one of the highest-risk rooms in your home when it comes to electrical safety. Water and electricity don’t mix, and the regulations around what you can and can’t install in a bathroom are stricter than in any other room. If you’re planning a bathroom renovation, adding a shower, or just want to understand the rules, here’s what you need to know.

Bathroom Electrical Zones Explained

The key concept behind bathroom electrical safety is the zoning system. Bathrooms are divided into specific zones, and the type of electrical equipment you can install depends on which zone it’s going into. These zones are defined in the BS 7671 wiring regulations (18th Edition).

Zone 0 — Inside the Bath or Shower Tray

This is the interior of the bath or shower tray itself. Only equipment rated at SELV (Separated Extra-Low Voltage) of maximum 12V can be installed here, and the transformer must be located outside Zones 0, 1 and 2. In practice, very little goes in this zone — perhaps a built-in whirlpool motor or LED bath light specifically designed for it. Everything must be rated at least IPX7 (protected against submersion).

Zone 1 — Directly Above the Bath or Shower

Zone 1 extends from the finished floor level (or the top of the bath/shower tray) up to 2.25 metres above it. Equipment installed here must be rated at least IPX4 (splash-proof) and must be suitable for the zone. This is where you’ll typically find electric showers, which are permitted in Zone 1 provided they’re designed for it. Switches are not permitted — only pull cords.

Zone 2 — The Area Surrounding Zone 1

Zone 2 extends 0.6 metres horizontally beyond Zone 1, and also includes the area above Zone 1 up to the ceiling (if the ceiling height is above 2.25m). Equipment here must be rated at least IPX4. Suitable light fittings, shaver sockets (with an isolating transformer), and extractor fans rated for the zone are all permitted.

Outside the Zones

Anything beyond Zone 2 is classed as outside the zones. Standard electrical equipment can be used here, although it’s still good practice to use splash-rated fittings given the humid environment. Standard 13A sockets are permitted outside the zones, but only if they’re at least 3 metres from the boundary of Zone 1.

What Can and Can’t Go in a Bathroom

Sockets

Standard 13A sockets are not permitted within Zones 0, 1 or 2. The only socket permitted within the zones is a shaver socket with an isolating transformer (BS EN 61558-2-5), which can go in Zone 2. If you want standard sockets — for example, for a heated towel rail on a plug or hair styling tools — they must be outside the zones and at least 3 metres from Zone 1.

Switches

Standard light switches are not permitted inside the zones. Pull cord switches are the standard solution and can be installed in Zone 1 or 2. If you want a wall-mounted switch, it must be located outside the zones — typically on the wall just outside the bathroom door.

Lighting

Bathroom lights must be IP-rated for the zone they’re installed in. Recessed LED downlights rated IP65 are the most popular choice — they’re suitable for Zones 1 and 2 and give a clean, modern look. Decorative pendants and exposed bulb fittings are generally only suitable outside the zones.

Extractor Fans

A good extractor fan is essential in any bathroom to control moisture and prevent mould. Fans installed in Zone 1 must be rated at least IPX4 and must be on a circuit protected by a 30mA RCD. Many bathroom fans are wired to come on with the light and run on for a set time after you leave — this is the most effective setup for moisture control. We’ve covered this topic in more detail in our post on getting bathroom extraction right.

Electric Showers

Electric showers are permitted in Zone 1 and must be supplied by their own dedicated circuit from the consumer unit, protected by an appropriately rated MCB and 30mA RCD. They require a separate isolation switch — usually a ceiling-mounted pull cord — which must be accessible from outside the shower area. Installation must be carried out by a qualified electrician.

Heated Towel Rails

Electric heated towel rails can be hardwired and installed in Zone 2 or outside the zones, provided they have an IP rating suitable for the zone. Hardwiring is generally preferred over a plug-in version in a bathroom, as it avoids the need for a standard socket within the zones.

Bathroom Electrics and Building Regulations

Any new electrical work in a bathroom is notifiable under Part P of the Building Regulations. This includes installing new circuits, adding or moving light fittings, installing an electric shower, adding an extractor fan, and fitting new sockets outside the zones.

The work must be carried out by a registered electrician (NAPIT, NICEIC or equivalent) or inspected and signed off by building control. Using a registered electrician means the notification is handled automatically — you don’t need to arrange a separate inspection.

Common Bathroom Electrical Mistakes

Over the years, I’ve seen plenty of bathroom electrical work that doesn’t meet regulations. Common issues include standard sockets installed inside the zones, non-IP-rated light fittings used above showers, missing or inadequate bonding, extractor fans not connected to the lighting circuit, and electric showers on undersized cables without dedicated circuits.

If you’re buying a property or renovating a bathroom and spot any of these, it’s worth having the installation checked with an EICR before using it.

Need Bathroom Electrics in Rotherham?

Whether you’re doing a full bathroom renovation or just need a fan or shower installing, I can make sure everything is done safely and to current regulations. I’m Mat from MP Electrical — a NAPIT registered electrician based in Rotherham, covering the whole of South Yorkshire.

Get a free quote or give me a call to discuss your bathroom electrical work.