Quick answer
Bathroom electrical zones divide the room by how close fittings are to water, to keep electrics safe. Zone 0 is inside the bath or shower tray, Zone 1 is directly above it, and Zone 2 is the area just beyond. Each zone sets a minimum IP (water-resistance) rating, and standard sockets are banned near the bath altogether.
Why zones exist
The wiring regulations treat a bathroom as a special location because the closer an electrical fitting is to water, the more protection it needs. Zoning is simply a way of mapping that risk onto the room: the splash zone right by the bath or shower demands the toughest, best-sealed fittings, while the far corner by the door can take more ordinary equipment. Get the zones right and a bathroom is perfectly safe; get them wrong and you risk a fitting that water can reach the live parts of.
Every fitting is given an IP rating — two digits describing how well it keeps out solids and water. The second digit is the one that matters in a bathroom: the higher it is, the more water the fitting can withstand. Zones tell you the minimum IP rating you must use in each part of the room.
The three zones, explained simply
Zone 0
Inside the bath itself or the shower tray — anywhere water actually collects. Only very low-voltage fittings specifically rated for full immersion (typically IPX7) belong here. In practice, almost nothing electrical goes in Zone 0.
Zone 1
The area directly above the bath or shower, up to 2.25m from the floor. Fittings here need a minimum of IPX4 (splash-proof), and any electric shower must be suitably rated and properly protected.
Zone 2
The strip extending 0.6m beyond Zone 1, and around a basin. IPX4 is the minimum here too. Shaver sockets to the relevant standard are allowed, but general 13A sockets are not.
Beyond Zone 2 — the “outside zones” area — ordinary fittings can usually be used, though everything in the room should still be on a circuit with RCD protection. Standard 13A sockets must be kept at least 3m from the edge of Zone 1.
Zone definitions and IP requirements can change between editions of the wiring regulations. Always confirm the current rules with a registered electrician or Plymouth City Council building control.
What this means for your design
Zoning quietly shapes a lot of design decisions, and it is one of the reasons a thought-through layout beats guesswork. It dictates which lights you can put over the shower, where the extractor fan can sit, whether you can have a heated mirror, and the only sensible place for a shaver socket. We factor all of this in at the design stage so the bathroom both looks right and passes muster.
- Downlights over a shower must be suitably IP-rated
- Extractor fans are positioned and rated for their zone
- Heated mirrors and demisters need the correct rating
- Sockets and shaver points go where the rules allow
Lighting over and around a shower is chosen for its zone — both for safety and a clean, even finish.
Common zoning mistakes we put right
When we strip out older Plymouth bathrooms — particularly DIY jobs or work done before the rules tightened — we sometimes find fittings in the wrong place. The usual culprits are an ordinary socket too close to the basin, a non-rated light over the shower, or a pull-cord that should have been used instead of a wall switch inside the room. Part of a proper refit is quietly correcting these so your new bathroom is safe and compliant.
This is why we always recommend a qualified electrician — see our answer on whether you need a qualified electrician. For the wider regulatory picture, our building regs guide is a useful companion read.
Frequently asked
Can I have a normal plug socket in a bathroom?
Generally no. Standard 13A sockets must be at least 3m from the edge of Zone 1. The exception is a shaver-supply unit to the relevant standard, which is allowed in certain positions.
What IP rating do I need over a shower?
Fittings in Zone 1, directly above the shower, typically need a minimum of IPX4 (splash-proof). Your electrician will confirm the right rating for the specific fitting and position.
Do light switches have to be outside the bathroom?
A pull-cord switch is the usual solution inside the room. A conventional wall switch is normally located outside the door, unless it is a suitably protected type in an allowed position.
Does a heated towel rail count?
Yes — its position and electrical supply must respect the zones. We site and wire it correctly as part of the installation. See our full bathroom installation page for how it all comes together.
Designed safe from the start
Let’s plan a bathroom that’s safe and beautiful
We design around the zoning rules so your lighting, heating and sockets are exactly where they should be — compliant, tested and certified.