Bathroom Electrical Regulations UK: What You Can and Can't Install

Why Bathrooms Have Special Electrical Rules

Water and electricity don't mix. UK regulations (BS 7671) set strict requirements for bathroom electrical installations to protect you from electric shock.

Bathroom Zones Explained

Bathrooms are divided into zones based on distance from water sources:

Zone 0 - Inside Bath or Shower

Location: Inside the bath tub or shower tray

What's allowed:

• Only SELV (12V max) equipment rated IPX7
• Practically nothing in domestic settings

Examples:

• Specialist underwater lights only

Zone 1 - Above Bath/Shower

Location: Directly above the bath or shower to 2.25m height

What's allowed:

• IPX4 rated equipment (splash-proof minimum)
• Electric showers (with appropriate rating)
• Instantaneous water heaters
• SELV lighting only (12V supply outside bathroom)

Not allowed:

• Standard light fittings
• Sockets
• Switches (except pull cords)

Zone 2 - Around the Bath/Shower

Location: 0.6m from edge of zone 1, to 2.25m height

What's allowed:

• IPX4 rated equipment
• Shaver sockets (with isolation transformer)
• Light fittings (IP44 minimum)
• Fans with appropriate rating

Not allowed:

• 13A sockets
• Standard switches

Outside Zones

Location: More than 0.6m from zone 1, and above 2.25m anywhere

What's allowed:

• Most electrical equipment (common sense applies)
• Sockets (3m from edge of zone 0)
• Light switches
• Towel rails

IP Ratings for Bathrooms

What You Can Install in a Bathroom

Electric Showers

Requirements:

• Dedicated circuit from consumer unit
• Correctly sized cable for power rating
• Appropriate MCB/RCBO protection
• Pull-cord switch or switch outside bathroom
• Adequate bonding

Zone: Can be in Zone 1

Bathroom Extractor Fans

Requirements:

• IPX4 rating minimum
• Often connected to light circuit
• Timer function recommended
• Humidistat versions available

Zone: Usually Zone 2 or outside

Towel Rails

Requirements:

• Electric towel rails fine in Zone 3/outside zones
• Hardwired preferred (no trailing cables)
• Thermostat controlled
• Fused connection unit outside bathroom

Underfloor Heating

Requirements:

• Electric mats with proper insulation
• Thermostat outside wet zones
• RCD protection essential
• Must be installed by qualified electrician

Lighting

Zone 0: Only 12V SELV (supply outside bathroom)

Zone 1: IPX4 rated, 12V SELV preferred

Zone 2: IP44 rated, 240V with RCD

Outside zones: Standard fittings acceptable

Shaver Sockets

Requirements:

• Must have isolation transformer (built-in)
• BS EN 61558-2-5 compliant
• Can be installed in Zone 2 or outside

Absolutely NOT Allowed

❌ Standard 13A sockets in zones 0, 1, or 2

❌ Standard light switches (use pull cords)

❌ Portable heaters

❌ Trailing extension leads

❌ Socket outlets within 3m of zone 0 (special rules)

Bonding Requirements

What is Bonding?

Supplementary bonding connects all metal parts to earth, ensuring they can't become live if a fault occurs.

What Needs Bonding?

• Metal baths (unless plastic waste)
• Metal waste pipes
• Metal water pipes
• Radiators and towel rails
• Metal window frames (if within zones)

Modern Exceptions

If the installation has RCD protection and main bonding is verified satisfactory, supplementary bonding may not be required. We assess this during installation.

Common Bathroom Electrical Questions

Can I have a socket in my bathroom?

Only shaver sockets. 13A sockets must be 3m from zone 0.

Can I fit my own bathroom light?

Technically yes if like-for-like, but bathroom electrical work is best left to qualified electricians due to complexity.

Do I need an isolator switch?

Yes, for showers. It should be accessible (outside bathroom or pull-cord inside).

What about wet rooms?

Same zone rules apply, but zone 1 extends to the entire room typically.

Why Use a Qualified Electrician?

• Bathroom work is notifiable under Part P
• Zones and IP ratings can be complex
• Incorrect installation is dangerous
• We provide proper certification

Need bathroom electrical work in Devon? Call Grant's Electrical Solutions on 01626 374 059 for compliant, certified installations.