Wall Light Installation

To a layperson it can look like a few screws and a couple of wires. A good electrician checks safety at every step, though, because older wiring can hide all sorts of surprises.

1. Switch off the relevant circuit breaker in the consumer unit (fuse box). The light switch alone is not enough. It may be wired incorrectly and leave the fitting live.
2. Use a voltage tester or multimeter to confirm the wires really are dead.
3. Remove the old fitting and check the condition of the wires, terminals and back box. This is often when hidden faults turn up, such as a cracked conductor, scorched insulation or a missing earth.
4. Identify the live, neutral and earth conductors. In older homes the wire colours may not match today's colour code, so an electrician confirms this by measuring.
5. Prepare the mounting point: mark the holes with a spirit level, check that no other cables run where you will drill, and choose wall plugs that suit the wall.
6. Connect the wires to the fitting's terminal block or to good-quality connectors, and check that each connection is tight.
7. Fix the light to the wall so it does not move and the wires are not trapped or pulled tight.
8. Switch the breaker back on and test switching on, switching off and dimming, if there is a dimmer.

The method is similar for most fittings, but some types have their own quirks.

• Fitting with a bulb holder: simple to install, but stick to the maximum bulb wattage the manufacturer gives. A stronger bulb overheats the holder and the wiring.
• LED fitting with a built-in light source: uses little energy, but some types have a separate power supply (a driver) that needs space in the back box or behind the fitting. LEDs also dislike heat, so do not cover them with insulation or panelling.
• Dimmable fitting: an old dimmer made for traditional bulbs often does not get on with LEDs. You notice it as flickering, buzzing, or a light that will not dim all the way. The dimmer and the fitting have to be compatible.
• Bathroom light: what matters here are the zones around the bath and shower and the IP rating, which shows how well the fitting is protected against water. The closer to water, the higher the rating needs to be. In practice at least IP44 is usually used, but the exact requirements come from your local wiring rules (generally based on IEC 60364, the part for bathrooms) and the manufacturer's instructions.
• Outdoor light: it must be made for outdoor use and well sealed against rain. In a block of flats the façade is usually a shared part of the building, so agree on it with the building management or owners' association beforehand.

How high should a wall light go? Bedside lights tend to sit lower, while lights in a hallway or on a staircase go higher, often around two metres above the floor. The main thing is that the light does not dazzle anyone and is not in the way.

The simplest case is a wiring point already in the right place, wires in good condition and a fitting with a clear mounting bracket. An electrician can then fit it quickly without touching the wall itself.

These situations usually make the job longer and more involved:

• The wiring point is not where the light should hang and has to be moved or extended, which means cutting a channel in the wall and making good the plaster afterwards
• The wall contains old aluminium wiring, which is brittle and tends to snap when bent
• The home has an older two-wire installation without an earth, which is common in some older houses and flats, and the fitting needs one
• The wall is plasterboard or aerated concrete block, which needs special fixings, or a heavier fitting has to be fixed into a stud or frame
• The fitting has a complicated bracket, a separate driver, a motion sensor or smart controls
• The job also involves replacing a switch or dimmer

If several lights are fitted at once, for example across a whole flat, the electrician can organise the work better and each light takes less time.

Connecting a light means working on the fixed electrical installation, so a qualified electrician should do it. Swapped conductors, a loose terminal or a missing earth are easy for a layperson to miss, yet they can cause electric shock, overheating or fire. In some countries certain electrical work also has to be certified or notified to the local authority, so check what applies where you live. For these reasons there is no DIY guide here.

What you can prepare yourself:

• Choose the fitting and check it suits the room (IP rating, dimmer compatibility)
• Keep the instructions and the fixings that come in the box
• Clear the space below the mounting point and move anything fragile
• In a block of flats, get approval from the building management in advance if the work involves the façade or shared areas

It is worth showing the electrician the fitting before you buy it, or sending them the model. That way you avoid buying a light that cannot be connected safely to your wiring.

• Live on the wrong side: the switch breaks the neutral instead of the live, so the fitting stays live even when switched off. Changing a bulb then carries a risk of shock.
• Earth not connected: with metal fittings this is a serious fault, because if something fails the whole body of the light can become live.
• Weak fixing: unsuitable wall plugs in plasterboard or aerated block. Over time the light loosens or falls.
• Too close to flammable materials: powerful fittings and halogens need the clearance from timber cladding or curtains that the manufacturer specifies.
• Indoor fitting in a damp place: in a bathroom or outdoors, a fitting without enough protection corrodes and can short-circuit.
• Bulb too powerful: a stronger bulb than the fitting allows shortens its life and puts strain on the connections.

When the job is handed over, check a few things on the spot while the electrician is still there.

• The light is firmly fixed and does not move when pressed gently
• It sits straight, which you can check with a spirit level or by eye against a door or window edge
• It switches on and off reliably, with no delay or flicker
• Dimming works smoothly across the whole range, if the fitting has it
• After a while of running, neither the fitting nor the wall around it gets excessively hot and nothing smells
• No wires show beneath the fitting and the hole in the wall is covered
• The area is free of dust and leftover materials
• You have been told which bulb or light source to use, how to look after the fitting and what guarantee applies to the work