As mentioned elsewhere on this site the bathroom lighting is subject to the wiring regulations, BS7671 and these must be applied to any electrical installation

For the layman the wiring regulations are a minefield of confusing terms and even for an electrician they can be somewhat confounding.

The bathroom light is situated in what is deemed to be a special location, ie one that contains a bath or shower. Everyone will understand that where you have electricity and an abundance of water there will be an element of increased danger and this is why the regulations are very specific as to what is considered safe.

The bathroom, for the purposes of the wiring regs, is divided up into zones which are 0, 1,2 and ‘outside zones.’ The outside zones is basically any part of the bathroom which does not fall into zones 0,1 or 2.

Zone 0 is defined as any area within the bath tub or shower tray and only certain equipment can be installed here. For the technically minded, equipment which is 12V ac or 30V ripple free DC safety exta low voltage with the safety source outside the zones. All equipment must be IPX7.

Zone 1 is the area which is vertically defined by the edges of the bath or shower to a height of 2.25 metres. Equipment must be IPX4 rated or IPX5 if jets are used. Some mains equipment is allowed in this area such as electric showers, whirlpool equipment, shower pumps and luminaires (bathroom lights)

Zone 2 extends from the edges of the bath or shower 0.6 metres horizontally and all equipment must again be IPX4 or 5.

All other areas are deemed to be outside the zones.

Other things to know about wiring your bathroom light:

All circuits in a bathroom need to be protected by an RCD of 30mA. Whilst this is the current regulation it is not obligatory to upgrade the circuit if you are only changing a light fitting. Any new circuit however must comply.

Bonding: You may have seen small green and yellow cables in bathrooms that connect together the pipes etc, this is bonding and prevents differing ptentials appearing across the various parts of the bathroom. Bonding should conect all metallic items together and the cpcs of all electrical circuits. Bonding may be omitted if every circuit is protected by an RCD and their respective cpcs join at the consumer unit.

As you can see, replacing your bathroom light may not be as simple as it first appears. Be safe, employ an electrician.

Changing the bathroom light in your home may be subject to the rules of the local authority and Part P legislation. Electrical work has to be carried out under the rules of BS 7671 or “The Regs” as most people will know it. The wiring regulations are now part of the building regulations and as such, are enforceable in law.

The Part P legislation requires electrical works in certain parts of your house to be carried out by an appoved electrician or to be notified to the local authority before the work commences.

If you are merely replacing a fitting that work does not need approval but where the wiring has to be altered or modified in any way the rules for notification will apply.

Why must this work be notified?

Simply for safety, the bathroom is an extremely hazardous place where electricity is concerned. A DIY botched job will present a danger to the occupier and also to any future occupier, with the present climate of “Where there is blame, there is a claim” any mishaps can cost you dear.

How Do You Notify The Work?

The simplest way is to employ a registered electrician who will carry out the work and then notify the relevant authorities that it has been done and to the correct standard. When you do employ an electrician make sure he is registered with an appropriate body to carry out domestic electrical work and ensure he or she issues you with a certificate stating the work done and the test results of that work.

Apart from the electrical safety of the actual wiring to your bathroom light there are other aspects which must be taken into account, the most important of which is the bonding of the circuit to any other circuit in the bathroom, an electrical heater for instance, and to any metalwork such as pipes and radiators.

The bathroom light may be fairly straightforward to swap out with another fitting. It may have just the one cable with a live, neutral and earth (cpc) but on many occasions there may also be wiring for an extractor fan and a loop in/loop out circuit. With this many cables it can be very confusing for someone who is not an electrician.

Our recommendation for anyone considering changing their bathroom liht is to employ an approved electrician and get it done right first time.