Adding a Socket: Cost, Chasing and When to Do It

By Steven Dixon · NAPIT-registered electrician, Royal Artillery veteran (26 years) · Published 8 September 2026 · Bradford, West Yorkshire

Adding a socket costs £90-£180 in most homes. It is one of the smallest jobs we do and one of the most requested, usually because somebody has finally got tired of an extension lead running across a doorway.

The advice that actually saves money on this job is not about price at all. It is about timing. Do it before the plasterer and it costs almost nothing extra. Do it after and you are paying someone to cut a channel into a wall you have just paid to finish.

The 30-second answer

The call-out is the fixed cost on a job this size. One socket on its own carries the whole of it; six sockets in a morning share it out. If you have a list, do the list.

Spur or new circuit?

This is what the electrician is working out in the first five minutes, and it decides the price.

Spurring from an existing point

On a standard ring final circuit you may take one unfused spur from a socket, from a junction box, or from the consumer unit. That spur may feed one single or one double socket — and that is the whole allowance.

What you cannot do:

• Spur off a socket that is already a spur
• Hang two or three sockets off one unfused spur
• Assume the point you are spurring from is on the ring — it may already be a spur, and there is no way to know by looking

That last point is why an electrician tests before connecting anything. A continuity test at the existing socket says immediately whether it is on the ring or already spurred. Guessing produces an overloaded spur that works perfectly well until the day it does not.

When you need a new circuit

A dedicated circuit back to the consumer unit is the answer when:

• The load is significant — a workshop, a bank of kitchen appliances, an electric heater
• The existing circuit is already at its limit, or the ring serves more than 100 square metres
• The sockets are outdoors or in an outbuilding — see our outbuilding electrics guide
• There is no spare capacity and no sensible point to spur from

A new circuit is notifiable under Part P. A spur, in an ordinary room, generally is not.

Where cables are allowed to go

This is the part that separates a proper job from a hazard, and it is invisible once the wall is finished.

Cables buried in walls must run in permitted safe zones: vertically or horizontally in line with the accessory they serve, or within 150mm of the top of the wall or of an internal corner. The logic is simple — anyone about to drill a wall can reasonably predict where the cable is by looking at the sockets and switches on it.

A cable run diagonally across a wall to save a metre of copper is outside the zones. It will pass every electrical test. It will work for twenty years. And then somebody hangs a mirror and finds it with a masonry bit.

There is a second protection: any cable buried at less than 50mm from the wall surface, outside of earthed containment, must be on an RCD-protected circuit. On a modern RCBO board everything is covered as a matter of course. On an old fuse box with no RCD, it is not — which is one of the reasons adding sockets to a pre-RCD installation often prompts a board conversation.

Chase depth

Chases weaken the wall, so they are limited: no deeper than a third of the wall thickness for a vertical chase, and a sixth for a horizontal one. Deep horizontal chases across a load-bearing wall are how you turn an electrical job into a structural one.

The timing that saves you money

Electrical work on a refurbishment happens in two stages, and understanding them is worth real money on any project.

• First fix — cables run and back boxes fitted, before plastering. Walls are open or about to be skimmed. The plasterer works to the boxes and the finish is seamless.
• Second fix — faceplates, switches and light fittings, after the plastering has dried and usually after decorating.

Add a socket during first fix and the incremental cost is a few metres of cable and twenty minutes. Add the same socket after the room is finished and you are cutting a fresh chase into new plaster, filling it, and repainting a wall that will never quite match. That is £60-£150 of avoidable cost per socket, and a fortnight of living with a patched wall.

So before the plasterer arrives, walk each room and ask where the furniture is actually going. The desk, the TV, the bedside tables, the kettle and the toaster, the Christmas tree corner, the spot where a robot vacuum will need to dock. Sockets are cheap at first fix and expensive afterwards. We would far rather fit four more now than come back in March.

This is the same logic that applies to a full rewire, where the difference between a well-planned and a poorly-planned socket layout is the difference between a house that works and one you spend a decade resenting.

Kitchens, bathrooms and outdoors

Kitchens

Worktop sockets sit above the surface, not behind an appliance where they cannot be reached to isolate it. High-current appliances — ovens, induction hobs, some American-style fridge freezers — want their own provision rather than being added to the general ring. Getting this right at first fix is the difference between a kitchen that works and one with an extension lead behind the kettle.

Bathrooms

Standard 13A sockets are not permitted within 3m of the edge of a bath or shower zone. Shaver supply units to BS EN 61558-2-5 are, and that is the correct answer for an electric toothbrush or a shaver. Bathroom work is a special location and it is notifiable under Part P, so it is not a DIY job. See our bathroom and extractor fan page.

Outdoors

An outdoor socket needs to be IP-rated for weather — IP66 with the lid closed is the usual specification — and RCD protected. Mount it out of the direct run-off from a roof or gutter. Feed it from a suitable circuit rather than spurring off the nearest indoor socket without checking the loading. For anything heavier than a mower or a jet wash, a 16A or 32A commando socket is the right fitting.

Certificates for small jobs

Adding a socket to an existing circuit should come with a Minor Electrical Installation Works Certificate. It is a single page recording what was done and the test results — continuity, insulation resistance, polarity, earth fault loop impedance and RCD operation.

A new circuit needs a full Electrical Installation Certificate and Part P notification instead. If someone adds a circuit and offers you a Minor Works form, they have used the wrong document.

Keep them. They are what a buyer's solicitor asks for, and they give the next inspector a baseline. It is a small job but it is still part of the record of the installation.

The bottom line

Budget £90-£180 for a straightforward socket addition, less per socket if you do several at once, and £250-£450 if it needs its own circuit. Have the work done before the plasterer. Make sure the cables run in the safe zones. Get the Minor Works Certificate.

And if the house has no RCD protection, adding sockets is a reasonable moment to deal with the consumer unit as well — a new cable buried in a wall on an unprotected circuit is exactly the situation the regulations are written around.

Get in touch with your list and we will price the lot in one visit.