How to fit ceiling lights

A guide to fitting, moving, and adding ceiling lights

As long as you can get to the ceiling void from above without too much hassle, it’s not complicated to move a light to wherever you really need it. Alternatively, you can boost your light levels by adding extra pendants which you operate either by the existing switch or with a new one.

Need some inspiration on ceiling light styles? Check out our wide range of ceiling lights.

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Remember to switch off the mains power at the consumer unit.

Before starting any electrical work, stay safe – get yourself a socket tester (or voltage tester for lighting circuits). They confirm whether circuits are dead and safe to work on.

Check all finished work with a socket tester (or voltage tester for lighting circuits) before using.

For your safety, these products must be installed in accordance with local Building Regulations. If in any doubt, or where required by the law, hire a professional. Further information is available online or from your local authority.

Never take risks with electrical safety. Before you start any type of electrical work, follow these safety precautions:

  • Switch off the main power at the consumer unit / fuse box. Isolate the circuit you plan to work on by removing the circuit fuse. Put this in your pocket to avoid losing it.
  • Or switch off the breaker and lock it if you can - put a note on the unit to advise you're working on the circuit.
  • Check the circuit is dead with a socket tester or voltage tester / meter for lighting circuits.
  • Pendants can only support a very lightweight bulb and shade – fittings over 2 kg must be chain supported.
  • Fittings with metal parts must be earthed with a three-core flex unless labelled as double insulated.

Once you have switched the power supply off, your first task is to find out what circuit type you have: junction box or loop-in. With the power turned off, remove your ceiling rose cover. You won’t be able to tell from the design of the rose – instead, you’ll need to count the cables entering it. If there’s only one cable then you have a junction-box wiring; if there are two or three, then you have a loop-in system.

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A single cable entering the rose

This indicates junction-box wiring.

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Two cables entering the rose

This indicates a loop-in circuit. The last rose on the circuit will have one circuit cable plus a switch cable.

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Three cables entering the rose

This indicates loop-in wiring; an intermediate rose on the circuit will have two circuit cables plus a switch cable.


Start by isolating the circuit, double-checking it’s dead and unscrewing the rose cover. When you’ve identified the type of wiring, disconnect the flex and feed cable.

With junction-box wiring - Step 1

Unscrew the rose base from the ceiling and push the cable back through. Above the ceiling, connect the cable to a three-terminal junction box. Then run a length of 1 mm² two-core-and-earth cable from your new light rose.

Step 2

Connect the brown core to the live terminal, the blue to the neutral terminal and the earth (insulated with green / yellow sleeving) to the earth terminal. Repair the ceiling at the old light position with filler.

With loop-in wiring - Step 1

Unscrew the rose base from the ceiling and push the cables back through. Mount a four-terminal junction box above the original light position.

Step 2

Connect the live, neutral and earth cores of the main circuit cable(s) to three separate terminals. Then connect the brown core of the switch cable to the circuit lives, the earth core to the circuit earths and the blue core to the fourth (unused) terminal. Finally, add a fourth cable to feed the light, connecting its brown core to the switch blue, its blue core to the circuit neutrals and its earth to the circuit earths. Then repair the ceiling at the old light position with filler.


If a single pendant fitting isn’t giving you enough light, you can always add another controlled by the same switch without too much trouble. The one limiting factor is the number of lighting outlets already powered by the circuit – so don’t risk overloading it.

Safety first

Flex can only support a very lightweight bulb and shade, so fittings over 2 kg must be supported by a chain. Ceiling light fittings with metal parts must be earthed via three-core flex unless they’re labelled as double-insulated.

With junction-box wiring - Step 1

First, double check the circuit is dead. Then cut the feed cable to the original light at a suitable position to install a three-terminal junction box. Run a length of 1 mm² two-core-and-earth cable from there to the new fitting.

With loop-in wiring - Step 1

Double check the power is off. Then run a spur cable from the original ceiling rose. This connects its brown core to the same terminal as the switch drop blue core (which should carry a length of brown PVC sleeving to show it can be live) and its blue core to the neutral circuit cores. The earth core goes to the earth terminal.

Step 2

At the new rose, connect the brown core to the terminal marked ‘live’ and the blue core to the terminal marked ‘neutral’. Take the earth core to the earth terminal, covering it in green / yellow sleeving. Connect the live (brown) core of the pendant flex to the live terminal and the neutral (blue) core to the neutral terminal.

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Running a spur from a loop-in rose

With a loop-in system, you can add a spur cable at the original ceiling rose to give power to a second light controlled by the same switch.


Whichever type of wiring you have, you may be able to run the switch cable back to the existing switch position. This replaces the original one-gang switch with a two-gang unit and gives you a neater installation.

With junction-box wiring - Step 1

Double check the circuit is dead, then cut the main circuit cable and install a four-terminal junction box. Connect the live cores of the split circuit cable to one terminal, the neutral cores to another and the earth cores to a third – adding green / yellow sleeving.

Step 2

Next, run a length of 1 mm² two-core-and-earth cable to the new light, and another to the switch. Connect the brown switch core to the circuit lives, its earth to the circuit earths and its blue core to the fourth terminal. Then add a length of brown PVC electrical sleeving to this core to show it can be live.

Step 3

Connect the brown core of the light cable to the switch drop’s blue core, its blue core to the circuit neutrals and its earth to the earth terminal.

With loop-in wiring - Step 1

Double check the power is off and run a spur cable from an existing rose on the circuit. This connects its brown core to the main circuit lives, its blue core to the main circuit neutrals and its earth to the earth terminal.

Step 2

At the new light position, connect its brown core to the central bank of terminals (which might be marked ‘loop’) and its blue core to the neutral terminal. Also, connect the earth to the earth terminal, adding green / yellow sleeving.

Step 3

Run in the switch drop cable at the new rose, connecting its brown core to the spur’s brown, its blue core (flagged brown) to the live terminal and its earth to the earth terminal.

Another option

With either type of wiring, you’ve got an additional option. You could connect a three-terminal junction box into the main circuit cable and run a spur from there to a loop-in rose with its own switch cable.

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Running a spur from a loop-in rose to a new rose and switch

With a loop-in rose, you can add a spur cable to provide power to a second light position controlled by its own switch.