Bathroom Electrical Zones and What Can Go Where

Bathroom electrical zones dictate exactly what electrical equipment can be installed near your bath or shower. Set out in Section 701 of the national wiring regulations, they divide the room into three distinct areas based on the risk of water reaching the electrical fittings. These rules are designed to keep any lighting, heating or shower equipment in the room safe to use with wet hands and damp skin.

Why bathrooms have electrical zones

Electricity and water are a hazardous combination, and washrooms present a specific set of risks. When your skin is wet, your body offers much less resistance to an electric current. The national wiring regulations manage this risk by imposing strict limits on what equipment can be installed and exactly where it can go.

These rules are found in Section 701 of BS 7671, which is the current UK standard for electrical installations. The standard is often simply called the Wiring Regulations, and any additions or alterations to an existing bathroom must meet the current version. Your electrician will use these zones to tell you exactly where you can safely place lights, extractor fans and heated towel rails.

The zones are numbered from zero to two, with zone 0 being the wettest area that requires the highest level of protection. The space outside the specific zones has fewer restrictions, but a bathroom remains a high risk environment overall. Because of this, strict safety rules apply to the entire room, not just the spaces right next to the water.

Zone 0 explained

The wettest area covers the interior of the bath tub or the shower basin itself. This is the space that actually holds water and where equipment is likely to be completely submerged. If you have a modern shower without a basin, zone 0 is defined as being 0.10 metres high from the floor and covers the same horizontal floor space as the zone above it.

Because this area fills with water, the rules on what you can fit here are incredibly strict. You can only install equipment that is fixed and permanently connected to the wiring. It must run on a safety extra low voltage (SELV) supply that does not exceed 12 V AC, and the safety power source for that supply must be placed entirely outside the bathroom zones.

Any equipment in this area must also have a minimum water protection rating of IPX7. This rating means the item is protected against temporary immersion in water. Finally, the manufacturer must specifically state in their instructions that the product is suitable for use in this exact location.

Zone 1 explained

The space directly above the bath tub or shower basin carries strict rules because it receives heavy spray. Zone 1 extends upwards from the rim of the bath or basin to a height of 2.25 metres from the floor. If you have a fixed shower head mounted higher than 2.25 metres, the zone extends all the way up to the height of that shower head.

The space underneath your bath is also classed as being in this zone if you can reach it without using a tool. If your bathroom features a shower without a basin, the zone extends 1.20 metres horizontally from the centre of the fixed water outlet. This larger area accounts for the way water splashes and spreads when there is no tray to contain it.

You can fit fixed, permanently connected equipment here if it is suitable for the location and has a minimum water protection rating of IPX4. Equipment running on a SELV or PELV supply not exceeding 25 V AC is also permitted. If you are having a new electric shower fitted, Electrical Safety First advises that it should be installed by a registered competent electrician and supplied on its own circuit.

Common items installed in this area include:

• Electric showers and shower pumps.
• Whirlpool units and ventilation equipment.
• Heated towel rails and water heaters.
• Light fittings with an IPX4 rating.

Zone 2 explained

A buffer area exists around the wettest parts of the bathroom to catch stray splashes. Zone 2 covers the space immediately outside the previous zone, stretching out for a distance of 0.6 metres horizontally. It reaches up to 2.25 metres from the floor or the height of the highest fixed shower head, whichever is taller.

If you have a shower without a basin, there is no buffer zone at all. Instead, the rules simply give you a much larger primary zone that extends 1.20 metres from the water outlet. This is because a flat floor allows water to bounce and travel further than a traditional shower tray.

Electrical equipment fitted here must have at least an IPX4 rating to protect against splashing water. You can install shaver supply units in this space, provided they meet the BS EN 61558-2-5 standard and are placed where direct spray from the shower is unlikely. Switches and sockets belonging to SELV circuits are also allowed here.

Bathroom zone rules at a glance

The table below compares the three bathroom zones on their location and minimum water protection.

Can you have a plug socket in a bathroom?

You cannot have a standard plug socket in a normal sized domestic bathroom. Electrical Safety First states that standard sockets are not allowed in bathrooms or shower rooms unless they can be fitted at least 2.5 metres horizontally from the edge of zone 1, the area above the bath or shower. In most UK homes, the bathroom is simply not large enough to meet this strict distance requirement.

The only exception to this 2.5-metre rule is a shaver supply unit. Shaver points are permitted closer to the bath as long as they are a safety extra low voltage (SELV) type or conform to the specific BS EN IEC 61558-2-5 standard. These units contain an isolating transformer, which is why they are allowed closer to the bath or shower than standard sockets.

You must never use extension leads to power appliances in a washroom. Running an extension cable from the landing or a bedroom into the bathroom bypasses all the carefully designed safety zones and creates a severe risk of electric shock. If you need power for a shaver or an electric toothbrush, ask your electrician to fit a proper shaver supply unit on the wall.

IP ratings in plain English

When you buy a new bathroom light or extractor fan, the box will display an IP rating. IP stands for Ingress Protection, and the two numbers that follow it tell you how well the item keeps out dust and water. For bathroom electrics, it is the second number that matters most, as this tells you the level of protection against moisture.

If the equipment has an IPX4 rating, the number four means it is protected against water splashing from any direction. This is the minimum level of protection required for items installed above the bath or in the buffer zone. The X simply means the item has not been specifically rated for dust protection, which is normal for bathroom fittings.

An IPX7 rating offers a much higher level of protection. The number seven means the equipment is completely protected against temporary immersion in water. You will only ever need this rating for items that sit permanently inside the bath or shower basin. Your electrician will check the IP rating of every item before installing it to ensure it is legal for the intended space.

RCD protection and bonding

Every electrical circuit in your washroom must have additional safety measures in place. A 30 mA RCD (residual current device) is required for all low voltage circuits serving the room, as well as any circuits that simply pass through the wet zones to reach another part of the house. An RCD constantly monitors the electrical current and trips the power in milliseconds if it detects a fault, which is vital for preventing serious shocks.

If your consumer unit is old and does not have RCD protection, your electrician will need to upgrade it or fit a separate RCD before they can add new bathroom circuits. A consumer unit replacement is a major job, but it is often necessary to bring an older home up to current safety standards. You can test your RCD yourself by pressing the small test button marked T on the consumer unit.

You may also hear your electrician talk about supplementary bonding. This involves connecting metal pipework and electrical earths together so they share the same voltage. Under the current rules, local supplementary bonding can be left out, but only where all the stated safety conditions are met, including the presence of full RCD protection.

Outside the zones

The space in your bathroom that falls further away from the water source is still heavily regulated. While this area is outside the numbered zones, it is still part of a room that fills with steam and condensation. The national wiring regulations still apply here to keep you safe.

Other equipment, switchgear and accessories are allowed outside the zones within the bathroom, provided their circuits are protected by a 30 mA RCD. This means standard light fittings and heaters can be installed here, as long as they are suitable for a damp environment. However, the rule banning standard plug sockets within 2.5 metres of the bath remains absolute.

When choosing how to turn your bathroom lights on and off, a ceiling mounted pull cord switch is a better option than a normal wall switch. Damp skin and wet hands make operating a standard switch risky, whereas a pull cord keeps the actual electrical contacts safely up on the ceiling.

Is bathroom electrical work notifiable?

Part P of the Building Regulations requires electrical work in a home to be designed and installed to protect people from fire and electric shock. Electricians working in England and Wales must comply with Part P, and all electrical installation work in a home must comply with the wider Building Regulations. However, the rules on when you must notify the local authority depend on exactly where you live.

In England, the rules were updated in April 2013 to reduce the range of notifiable work. Alterations to existing circuits, such as adding an extra lighting point, are only notifiable if they take place in special locations. In England, these special locations are defined strictly as the spaces around baths and showers. Installing a complete new circuit or a new consumer unit is always notifiable regardless of the room.

According to the Planning Portal, in Wales the definition of special locations also includes kitchens and outdoors. In Scotland, the Building Standards system applies and electrical work carried out under a building warrant must either be approved by a registered installer or checked by the local authority. There is currently no equivalent statutory requirement in Northern Ireland.

If your installer is not registered with a government-authorised competent person scheme, any notifiable work must be inspected, approved and certificated by a building control body. In England only, it can also be signed off by an electrician registered with a third party certification scheme. Using a registered electrician who can self-certify their own work is usually simpler.

Paperwork and certification for bathroom electrics

When your bathroom project is finished, you should receive the correct paperwork to prove the installation is safe and legal. When you use a registered electrician, you should receive an Electrical Installation Certificate for new circuits, or a Minor Works Certificate for smaller alterations. These documents confirm that the work meets the BS 7671 wiring regulations.

For notifiable work in England and Wales, you should also receive a Building Regulations Compliance Certificate. This confirms that the work meets the requirements of Part P and the wider building regulations. You should keep both of these certificates safely, as a buyer's solicitor is likely to ask for them when you sell your home.

If you are a landlord, you have legal duties to ensure the electrical installation is inspected at least every five years. The new bathroom wiring will form part of your next electrical inspection, and having the correct certificates proves that it was installed correctly by a competent person.

Avoiding common problems with bathroom electrics

When hiring someone to work on your bathroom electrics, it pays to be aware of the common problems customers face. One major issue is unregistered work carried out with no certificate and no notification to building control. If an unregistered person alters a circuit in the space around your bath or shower in England, building control must be told before the work starts.

You should also be wary of being told a full rewire or a new consumer unit is compulsory without seeing any test evidence. While older fuse boxes often need upgrading to provide the required RCD protection for a bathroom, a good electrician will explain exactly why this is necessary and show you the test results. Never hand over large cash deposits with no paperwork, and always ensure you understand what is included before the work begins.

A proper fixed price quote should clearly state whether it includes VAT, the cost of materials, the final certification, and the making good of any plaster and decoration.

Under the Consumer Rights Act 2015, any electrical service must be carried out with reasonable care and skill. If an installer leaves you with poor work, you can ask for it to be put right at no extra cost. Services arranged at home or online usually carry a 14-day cooling-off period, but this does not automatically apply to urgent repairs you have specifically asked for.

Common questions

What happens to the zones if a shower has no tray?

If you have a wet room or a shower without a basin, the zones change to reflect the way water spreads across a flat floor. There is no buffer zone at all. Instead, the primary zone extends horizontally for 1.20 metres from the centre of the fixed water outlet, and the wettest zone is defined as being 0.10 metres high across that same floor space.

Can I have a normal light switch inside the bathroom?

Wall-mounted light switches are generally not recommended inside a bathroom because operating them with damp and wet hands increases the risk of a shock. A ceiling mounted pull cord switch is a much better and safer option. If you do want a wall switch, it must sit completely outside the zones and be suitable for the damp conditions.

Do I need a certificate just to change a bathroom light?

Most repairs, replacements and maintenance jobs are not notifiable, but adding a light or altering a circuit in the space around a bath or shower is, so your electrician will confirm which applies to your job. Any addition or alteration to an existing bathroom must still meet the wiring regulations, and a registered electrician can issue a Minor Works Certificate to confirm the new light fitting is safe and suitable for its zone.

Can I put a heated towel rail in zone 1?

Yes, a heated towel rail can be installed in the space above the bath or shower tray. It must be fixed, permanently connected to the wiring, and have a minimum water protection rating of IPX4. The circuit supplying it must also be protected by a 30 mA RCD.

Planning bathroom electrics with your electrician

Getting your bathroom electrics right requires careful planning before any tiling or plastering begins. Electrical work in wet areas carries strict rules and high risks, so it is always best to involve a professional early in the project. Following a few simple steps will help you get accurate quotes and a safe installation.

• Check the exact location of your planned shower, bath and basin to see where the zones will fall.
• Look for the IP rating on any lights or extractor fans you want to buy, ensuring they are at least IPX4.
• Ask your electrician to check if your current consumer unit has the 30 mA RCD protection required for bathroom circuits.
• Check that your chosen electrician is registered with a competent person scheme like NICEIC or NAPIT so they can self-certify notifiable work.
• Ensure your quote includes the cost of the necessary certification and the building regulations notification.
• Ask if the fixed price includes making good any plasterwork chased out for new cables.

Bathroom zones exist entirely to keep you and your family safe from electric shocks. By understanding the basics of where water and electricity mix, you can choose the right fittings and plan a layout that works. When you are ready to start getting quotes, you can use our directory to find an electrician near you who understands the regulations and will complete the work safely.