Can I move a light switch myself?

The question is nearly always driven by a door hung the wrong way, a wall that got moved, or a switch behind a new wardrobe. It is worth separating the electrical part, which is modest, from the building part, which is most of the work and most of the cost.

Safety

Step by step

1. Ask whether you need to move it at all.A wireless retrofit switch — a battery transmitter that sticks to the wall with a receiver at the light — solves the door-hung-wrong-way problem in ten minutes, with no plaster disturbed. So does a smart switch or a smart bulb with a wall remote.
2. Understand what moving it involves.A new switch drop from the ceiling void or an extended cable from the old position, a new back box, cable chased into the wall inside permitted safe zones, the old position blanked or made good, and the plaster and decoration repaired.
3. Learn the safe zones before any cable goes in a wall.Cable must run vertically or horizontally from an accessory, or within 150mm of the top of the wall or of a corner. Diagonal runs across a wall are the classic way to leave a cable exactly where nobody expects to find it.
4. Know the cable depth rule.A cable buried less than 50mm from the surface, and not within a safe zone or in earthed metal containment, must have 30mA RCD protection. This is one of many reasons a modern consumer unit matters.
5. Never simply plaster over the old box.Any conductors left behind must be properly terminated in an accessible or maintenance-free enclosure, or removed back to their source. A live cable end buried in a wall behind filler is a hazard for the life of the building.
6. Consider whether the switch is two-way.A landing or hallway switch may be one of a pair, with strappers running to the other position. Moving one of a two-way pair is meaningfully more involved than moving a one-way switch.
7. Decide honestly.If you can isolate, prove dead, run cable in the correct zones, terminate correctly, and verify the result, this is within reach. If you cannot test it afterwards, get an electrician and ask for a Minor Electrical Installation Works Certificate.
8. Combine it with other work.Chasing and making good is the expensive part. If a room is being replastered or decorated anyway, that is the moment to move switches and sockets and it costs a fraction of doing it in isolation.

Tips

• Standard switch height in new UK work is around 1150mm to the centre. Matching the rest of the house looks better than matching an arbitrary number.
• Photograph the wall with the chase open before it is filled. That photograph is genuinely valuable the next time anyone drills that wall.
• If the wall is plasterboard on studs, running the cable is far easier — but the cable still has to be protected where it passes through studs and still has to follow safe zones.

Common mistakes

• Running the cable diagonally to save chasing — It puts a live cable where no detector user expects it and where safe-zone logic says there is nothing. It is the single most dangerous shortcut in domestic wiring alteration.
• Leaving the old cable live and buried — A buried live end is a permanent hazard, and it is undetectable. Everything must be terminated in an accessible enclosure or removed.
• Extending a cable with a connector block hidden in the wall — Connections must be accessible for inspection or made with a maintenance-free connector designed for burying. A choc block behind plaster is neither.

If it doesn't work

Questions people ask