Water and electricity are a dangerous combination, and bathrooms are the one room in your home where the two are guaranteed to meet. That is why the wiring regulations in BS 7671 (the IET Wiring Regulations) and Part P of the Building Regulations treat bathrooms differently from every other room.
If you are planning a bathroom renovation, upgrading your lighting, or fitting an electric shower, this guide covers everything you need to know about bathroom electrics in 2026 — the zones, the IP ratings, what counts as notifiable work, and where DIY ends and a registered electrician must take over.
Why Bathrooms Are Treated Differently
Wet skin has a much lower electrical resistance than dry skin, which means the same voltage that would give you a mild tingle in the kitchen could cause a serious — even fatal — shock in the bathroom. Add standing water, steam, and splashing into the equation and the risk increases again.
To manage this, the regulations divide every bathroom into protective zones, each with strict rules about what electrical equipment can be installed and how it must be protected.
Bathroom Zones Explained
Understanding bathroom zones electrical classifications is the foundation of any safe bathroom installation. There are four areas to know:
Zone 0 — Inside the Bath or Shower Tray
This is the interior of the bath or shower basin itself. Only equipment rated at a maximum of 12V SELV (Separated Extra-Low Voltage) is permitted here, with the transformer located outside the bathroom. In practice, almost nothing is installed in Zone 0.
IP rating required: IPX7 (protected against temporary immersion in water).
Zone 1 — Directly Above the Bath or Shower
Zone 1 extends from the finished floor level up to 2.25 metres above it, directly over the bath or shower tray. Electric showers, instantaneous water heaters and shower pumps may be fitted here provided they are suitably rated.
IP rating required: IPX4 minimum (protected against splashing from all directions). Many electricians specify IPX5 where jets of water are likely.
Zone 2 — The Area Surrounding the Bath or Shower
Zone 2 stretches 0.6 metres horizontally beyond Zone 1 and also includes the area above Zone 1 up to 2.25 metres. This zone also includes a 0.6-metre radius around a wash basin.
IP rating required: IPX4 minimum.
Outside Zones
Anything beyond Zone 2 is classified as outside the zones. Standard domestic fittings can be used here, but they must still be connected to an RCD (residual current device) rated at 30mA. Pull-cord switches and shaver supply units are common in this area.
IP Ratings for Bathroom Fittings — Quick Reference
| IP Rating | Protection Level | Suitable For |
|---|---|---|
| IPX4 | Splash-proof from any direction | Zones 1 and 2 |
| IPX5 | Low-pressure water jets | Zones 1 and 2 (wet rooms, power showers) |
| IPX7 | Temporary immersion (up to 1m) | Zone 0 |
When purchasing bathroom lighting or extractor fans, always check the IP rating on the box. If it does not have one, it does not belong in a bathroom.
What Needs a Qualified Electrician? (Part P and Notifiable Work)
Under Part P of the Building Regulations (England and Wales), most electrical work in a bathroom is classified as notifiable. That means it must be either carried out by an electrician registered with a competent person scheme (such as NICEIC), or inspected and certified by Building Control after the work is completed.
Notifiable bathroom work includes:
- Installing a new circuit (e.g. for an electric shower)
- Adding or moving a light fitting, switch or socket
- Fitting an extractor fan connected to the mains
- Any work within Zones 0, 1 or 2
The only bathroom electrical work a homeowner can legally do without notification is like-for-like replacement — for example, swapping an existing pull-cord switch for an identical one, or changing a light fitting for another with the same IP rating on an existing circuit.
If in doubt, it is always safer (and cheaper in the long run) to use a registered electrician. At F&A Electrical, every bathroom job we complete comes with the appropriate Building Regulations compliance certificate at no extra charge.
Common Bathroom Electrical Jobs and Typical London Costs
Here is a rough guide to what common bathroom electrical work costs in London in 2026:
| Job | Typical London Price |
|---|---|
| Electric shower installation (new circuit from consumer unit) | £350 – £600 |
| Extractor fan (with timer/humidity sensor) | £180 – £300 |
| Bathroom downlights (set of 4, IP65) | £250 – £400 |
| Heated towel rail (hardwired) | £150 – £250 |
| Shaver socket (transformer type) | £120 – £200 |
| Full bathroom rewire (as part of renovation) | £500 – £900 |
These are guide prices for straightforward installations. Older properties — particularly Victorian and Edwardian homes common across Hackney, Islington and Camden — may need additional work if existing wiring is not up to current standards.
Bathroom Lighting Regulations: What You Should Know
- Every light fitting within Zones 1 and 2 must carry the correct IP rating — typically IP65 for recessed downlights, IP44 minimum for other fittings.
- Standard light switches are not permitted inside the bathroom. Use pull-cord switches or fit the switch outside the door.
- 12V LED downlights are a popular choice. The transformer must be located outside Zones 0, 1 and 2 wherever possible.
- All bathroom lighting circuits must be protected by a 30mA RCD.
If you are wondering “can I install a light in my bathroom?” — you can replace a fitting on an existing circuit with a like-for-like swap, but installing a new lighting circuit or adding fittings where none existed before is notifiable work.
Safety Tips for Bathroom Electrics
- Never use portable electrical appliances (hairdryers, straighteners, phone chargers) plugged into an extension lead in the bathroom.
- Test your RCD regularly. Press the test button on your consumer unit every three months. If it does not trip, call an electrician.
- Watch for warning signs. Flickering lights, a burning smell, or a tingling sensation from taps or pipes all warrant an urgent inspection.
- Keep existing installations maintained. If your bathroom wiring has not been inspected in more than ten years, an EICR will flag any issues before they become dangerous.
- Use a registered electrician for all new work. NICEIC, NAPIT or ELECSA registration means the installer can self-certify compliance with Building Regulations.
Need Help With Bathroom Electrics in London?
F&A Electrical is NICEIC approved and carries out bathroom electrical work across North and East London, including Camden, Hackney, Islington, Tower Hamlets and Southwark. Whether you need an electric shower installation in London, new bathroom downlights, or a complete bathroom rewire, we will make sure everything is safe, compliant and certified.
Get a free, no-obligation quote — call us or use our contact form and we will get back to you the same day.
This guide is for general information only and does not replace professional advice. Electrical regulations are updated periodically — always check with a registered electrician before starting work.