Bathroom Zones Explained: UK Electrical Safety Guide
Planning a bathroom renovation or installing new electrical fixtures? Understanding UK bathroom electrical zones isn't just about compliance it's about keeping your family safe. Every year, electrical accidents in bathrooms cause serious injuries that could have been prevented with proper knowledge of these regulations.
This comprehensive guide explains everything you need to know about bathroom zones, IP ratings, and where you can safely install towel rails, heaters, lights, and other electrical equipment in your bathroom.
What Are Bathroom Electrical Zones?
Bathroom electrical zones are designated areas defined by BS 7671 (IET Wiring Regulations) that determine what type of electrical equipment can be safely installed and where. These zones exist because water and electricity are a dangerous combination—the closer to water sources, the stricter the requirements.
The regulations divide your bathroom into specific zones based on proximity to water sources like baths, showers, and basins. Each zone has different rules about:
- What voltage equipment is permitted
- Minimum IP (Ingress Protection) ratings required
- Types of fixtures and appliances allowed
- Installation requirements and restrictions
The Four Bathroom Zones Explained
Let's break down each zone in detail, starting from the highest-risk area closest to water:
Zone 0 – Inside the Bath or Shower
Zone 0 is the interior of the bath tub or shower tray itself—the area that holds water during use. This is the highest-risk zone where direct water immersion occurs.
| Zone 0 Requirements | Details |
|---|---|
| Maximum Voltage | 12V AC or 30V DC (SELV only) |
| Minimum IP Rating | IPX7 (protected against immersion) |
| Permitted Equipment | SELV equipment rated IPX7 (e.g., underwater lights) |
| Prohibited Items | Mains voltage equipment, switches, sockets |
Practical examples for Zone 0:
- ✅ 12V LED underwater bath lights (IPX7 rated)
- ✅ Low voltage whirlpool jet controls
- ❌ Any mains voltage equipment
- ❌ Standard light fittings
- ❌ Towel rails or heaters
Zone 1 – Above the Bath or Shower
Zone 1 extends from the finished floor level (or top of the bath/shower tray) up to 2.25 metres high, directly above the bath or shower. This zone experiences significant water spray and steam.
| Zone 1 Requirements | Details |
|---|---|
| Maximum Voltage | 240V permitted with restrictions |
| Minimum IP Rating | IPX4 (protected against splashing) |
| Permitted Equipment | Fixed equipment rated minimum IPX4, connected via FCU |
| Height Limit | 2.25 metres from floor level |
Practical examples for Zone 1:
- ✅ IPX4 rated shower lights
- ✅ Electric showers (specifically designed for this zone)
- ✅ SELV heated mirrors
- ✅ Instantaneous water heaters (if IPX4+)
- ❌ Standard towel rails
- ❌ Plug sockets
- ❌ Switches (except pull cords)
Zone 2 – Adjacent to Bath or Shower
Zone 2 extends 0.6 metres horizontally from the outer edge of Zone 1 (the bath or shower perimeter), and vertically from floor level to 2.25 metres. This area may receive occasional splashes.
| Zone 2 Requirements | Details |
|---|---|
| Maximum Voltage | 240V permitted with restrictions |
| Minimum IP Rating | IPX4 (IPX5 if water jets used for cleaning) |
| Horizontal Extent | 0.6 metres from Zone 1 boundary |
| Permitted Equipment | Fixed equipment rated minimum IPX4 |
Practical examples for Zone 2:
- ✅ IPX4 rated towel rails
- ✅ Bathroom light fittings (IPX4)
- ✅ Shaver sockets (with isolation transformer)
- ✅ Electric towel rails with appropriate IP rating
- ✅ Extractor fans (IPX4)
- ❌ Standard 13A plug sockets
- ❌ Portable heaters
Outside Zones – The Rest of the Bathroom
Any area beyond 0.6 metres from Zone 2 and below 2.25 metres, or any area above 2.25 metres throughout the bathroom, is considered "outside zones." While safer, caution is still required.
| Outside Zones Requirements | Details |
|---|---|
| Voltage | 240V permitted |
| IP Rating | No specific requirement (but IPX4 recommended) |
| Permitted Equipment | Most fixed equipment, with RCD protection |
| Special Consideration | Risk of water jets must be assessed |
Practical examples outside zones:
- ✅ Standard towel rails (still recommend IPX4)
- ✅ Bathroom light fittings
- ✅ Electric radiators
- ✅ Heated towel rails
- ✅ Shaver sockets
- ⚠️ 13A sockets (only 3+ metres from bath/shower, with RCD)
Understanding IP Ratings for Bathroom Equipment
IP (Ingress Protection) ratings tell you how well a device is protected against solid objects and water. For bathrooms, the second digit (water protection) is crucial.
IP Rating Breakdown
| IP Rating | Water Protection Level | Suitable Zones |
|---|---|---|
| IPX0 | No protection | Not suitable for bathrooms |
| IPX1 | Dripping water | Not suitable for bathrooms |
| IPX2 | Dripping water (tilted) | Not suitable for bathrooms |
| IPX3 | Spraying water | Outside zones only (limited) |
| IPX4 | Splashing water | Zones 1, 2 & outside ✓ |
| IPX5 | Water jets | All zones (not immersion) |
| IPX6 | Powerful water jets | All zones (not immersion) |
| IPX7 | Temporary immersion | Zone 0, 1, 2 & outside ✓ |
| IPX8 | Continuous immersion | All zones including Zone 0 |
Key point: The 'X' in IPX4 means the dust protection rating isn't specified. For bathrooms, you might see ratings like IP44 (protected against objects >1mm and splashing water) or IP65 (dust-tight and protected against water jets).
Where Can You Install a Towel Rail?
This is one of the most common questions we receive at Elegant Radiators. Here's the definitive answer:
Central Heating (Wet) Towel Rails
Central heating towel rails connected to your home's heating system can generally be installed in Zone 2 or outside zones. Since they don't contain electrical components, the primary concerns are:
- Adequate clearance from shower spray
- Proper pipework installation
- Accessibility for bleeding and maintenance
Electric Towel Rails
Electric towel rails have stricter requirements due to their electrical components:
| Zone | Electric Towel Rail Installation |
|---|---|
| Zone 0 | ❌ Not permitted |
| Zone 1 | ❌ Not permitted (unless specifically rated and SELV) |
| Zone 2 | ✅ Permitted if IPX4 rated, hardwired via FCU |
| Outside Zones | ✅ Permitted, still recommend IPX4, hardwired |
Important: Electric towel rails should always be:
- Hardwired (not plugged in) via a Fused Connection Unit (FCU)
- Protected by a 30mA RCD
- Installed by a qualified electrician (Part P certified)
- Minimum IPX4 rated if in Zone 2
Dual Fuel Towel Rails
Dual fuel towel rails operate on both central heating and electricity. The electric element must comply with the same regulations as fully electric rails—meaning Zone 2 or outside zones, with appropriate IP rating and hardwired installation.
Other Bathroom Electrical Equipment by Zone
Bathroom Lighting
| Zone | Lighting Requirements |
|---|---|
| Zone 0 | SELV only (max 12V), IPX7 minimum |
| Zone 1 | SELV recommended, or 240V with IPX4 minimum |
| Zone 2 | IPX4 minimum required |
| Outside | No specific IP requirement (IPX4 recommended) |
Extractor Fans
Bathroom extractor fans can be installed in Zone 1 (if IPX4+ rated) or Zone 2 and beyond. They must be connected to a suitable isolator switch and protected by RCD.
Electric Showers
Electric showers are specifically designed for Zone 1 installation. They must be:
- Minimum IPX4 rated
- Connected via a ceiling-mounted double-pole isolator
- Fed by a dedicated circuit with appropriate MCB/RCD protection
- Installed by a qualified electrician
Shaver Sockets
Shaver sockets with isolation transformers (BS EN 61558-2-5) can be installed in Zone 2 or outside zones. These contain transformers that isolate the socket from mains electricity, making them safer in bathroom environments.
Underfloor Heating
Electric underfloor heating can be installed throughout the bathroom but must:
- Have earthed metallic grid or sheath
- Be protected by 30mA RCD
- Be installed according to manufacturer specifications
Special Considerations
Wet Rooms
In wet rooms (rooms without a defined shower tray), the entire room is typically considered Zone 1 up to 2.25m high. This significantly restricts where electrical equipment can be installed. Always consult a qualified electrician for wet room installations.
Walk-In Showers
For walk-in showers without doors or screens, Zone 1 extends from the shower head/spray area. The exact zone boundaries depend on the shower configuration and should be assessed individually.
Windows Within Zones
If a window opens within Zone 1 or 2, the zones extend to include the space outside the window that could be reached by someone in the bath or shower.
Ceiling Height Considerations
Zones only extend to 2.25 metres from floor level. Above this height, requirements are relaxed, but equipment should still be suitable for humid environments.
Part P Building Regulations
Part P of the Building Regulations governs electrical work in dwellings, including bathrooms. Key points:
- Notifiable work: New circuits in bathrooms must be notified to Building Control or certified by a Part P registered electrician
- Non-notifiable work: Like-for-like replacements (same position, same type) may not require notification
- Certificate required: Electrical Installation Certificate (EIC) or Minor Works Certificate
- RCD protection: All bathroom circuits require 30mA RCD protection
Our recommendation: Always use a Part P certified electrician for any electrical work in bathrooms. This ensures compliance, safety, and provides documentation for insurance and property sales.
Common Mistakes to Avoid
Based on our experience helping thousands of customers, here are the most common bathroom zone mistakes:
- Installing standard light fittings: Using non-IP rated lights in wet areas
- Plug-in towel rails: Using portable or plug-in heaters in bathrooms
- Ignoring zone boundaries: Not measuring distances from bath/shower correctly
- DIY electrical work: Attempting electrical installations without qualifications
- Wrong IP ratings: Installing IPX3 equipment where IPX4 is required
- Forgetting about extractor fans: Not accounting for fan location when planning zones
- Wet room confusion: Not recognising that entire wet rooms may be Zone 1
How to Measure Bathroom Zones
Follow these steps to accurately determine zones in your bathroom:
- Identify water sources: Mark the position of bath, shower, and basin
- Mark Zone 0: This is simply inside the bath/shower tray
- Mark Zone 1: Measure 2.25m vertically from floor above bath/shower
- Mark Zone 2: Measure 0.6m horizontally from the edge of Zone 1
- Everything else: Areas beyond these measurements are outside zones
Pro tip: Draw a simple floor plan and mark the zones before purchasing any electrical equipment. This helps visualize where fixtures can be safely installed.
Buying Guide: What to Look For
When purchasing electrical equipment for your bathroom, check for:
- IP rating clearly stated: Should be on packaging and product label
- Compliance marks: CE/UKCA marking, relevant British Standards
- Installation instructions: Should specify suitable bathroom zones
- Warranty terms: Check if warranty covers bathroom installation
At Elegant Radiators, all our electric towel rails clearly display their IP ratings and suitable installation zones. If you're unsure about suitability for your bathroom, our team is always happy to advise.
Summary: Quick Reference Guide
| Equipment | Zone 0 | Zone 1 | Zone 2 | Outside |
|---|---|---|---|---|
| Electric Towel Rail | ❌ | ❌ | ✅ IPX4 | ✅ |
| Central Heating Towel Rail | ❌ | ⚠️ | ✅ | ✅ |
| Light Fitting | ✅ 12V IPX7 | ✅ IPX4 | ✅ IPX4 | ✅ |
| Extractor Fan | ❌ | ✅ IPX4 | ✅ IPX4 | ✅ |
| Shaver Socket | ❌ | ❌ | ✅ | ✅ |
| 13A Socket | ❌ | ❌ | ❌ | ✅ 3m+ |
| Electric Shower | ❌ | ✅ | ✅ | ✅ |
| Pull Cord Switch | ❌ | ✅ | ✅ | ✅ |
Frequently Asked Questions
What IP rating do I need for a towel rail in the bathroom?
For Zone 2 installation, you need minimum IPX4 (splash-proof). For outside zones, no specific rating is legally required, but we strongly recommend IPX4 for safety and longevity in humid bathroom environments. All quality bathroom towel rails should be at least IPX4 rated.
Can I install an electric towel rail myself?
Technically, you can purchase and position the towel rail yourself, but the electrical connection must be done by a qualified, Part P certified electrician. This is a legal requirement under Building Regulations. DIY electrical work in bathrooms can be dangerous and may invalidate your home insurance.
How far should a towel rail be from the shower?
An electric towel rail should be installed in Zone 2 or beyond—meaning at least 0.6 metres from the outer edge of the shower or bath. Central heating towel rails can be closer but we recommend the same distance for practical reasons like avoiding direct water spray.
What is the difference between Zone 1 and Zone 2?
Zone 1 is directly above the bath or shower, extending to 2.25m from floor level—this area receives direct water spray. Zone 2 extends 0.6m outward from Zone 1's perimeter—this area may receive occasional splashes. Zone 1 has stricter requirements for electrical equipment.
Can I have a plug socket in my bathroom?
Standard 13A plug sockets are only permitted 3 metres or more from the bath or shower, protected by RCD, and are generally not recommended in bathrooms. Shaver sockets with isolation transformers can be installed in Zone 2 or beyond and are the preferred option for bathrooms.
Do bathroom zones apply to en-suites and cloakrooms?
Yes, bathroom zones apply to any room containing a bath, shower, or similar water source, regardless of size. This includes en-suites, cloakrooms with showers, and wet rooms. Rooms with only a WC and basin have different, less restrictive requirements.
What happens above 2.25 metres height?
Above 2.25 metres from floor level, the zone restrictions don't apply in the same way. However, any electrical equipment should still be suitable for humid environments, and all bathroom circuits require RCD protection regardless of height.
Are LED lights safer in bathrooms?
LED lights can be safer because many operate on low voltage (12V or 24V SELV), making them suitable for more zones including Zone 1. However, the critical factor is the IP rating, not the bulb type. A mains voltage LED fitting needs the same IP rating as any other mains voltage light for each zone.
Do these regulations apply to Scotland and Northern Ireland?
The wiring regulations (BS 7671) apply across the UK. However, building regulations vary slightly: England and Wales use Part P, Scotland has different building standards, and Northern Ireland has its own regulations. The technical requirements for zone compliance remain consistent.
Can I install a heated mirror in Zone 1?
Yes, heated mirrors can be installed in Zone 1 if they are SELV (Safety Extra Low Voltage) and rated minimum IPX4. The transformer/power supply must be located outside Zone 1. Always check the manufacturer's specifications for zone suitability.
Need Help Choosing the Right Towel Rail?
Understanding bathroom zones is the first step to a safe and compliant bathroom heating solution. At Elegant Radiators, we offer a wide range of heated towel rails suitable for every zone, including:
- Electric towel rails with IPX4+ ratings
- Chrome towel rails for central heating systems
- Dual fuel towel rails for year-round warmth
Have questions about which towel rail is right for your bathroom? Contact our expert team or use our BTU calculator to find the perfect size for your space.
This guide is for informational purposes only. Always consult a qualified electrician for specific installation advice and ensure compliance with current regulations.
