Outdoor sockets and garden power: cost and what is involved

An outdoor double socket on the back wall of the house costs from £100 + VAT (£120 inc VAT) fitted, where there is a circuit close by to feed it from, and each further socket on the same run costs a good deal less than the first. A proper supply out to a shed, workshop or garden room is a different job altogether: its own armoured cable, buried to depth, and its own protection at both ends. Those are surveyed rather than priced off a list, because the trench decides it.

Outdoor power is regular work for Ryan, from a socket for the pressure washer to a full supply for a garden office.

An outdoor socket on the house wall

This is the simple one. A weatherproof socket is fitted on the outside wall, usually fed from a circuit just inside, with the cable going straight through the wall.

What makes it cost more:

• Distance from a suitable circuit. If the nearest one is on the other side of the house, the cable has a longer way to go.
• No RCD protection. Every outdoor socket must be RCD protected. If the existing circuit is not, that has to be sorted, and on an old fuse box it can mean a new consumer unit.
• Switching from inside. Some people like to switch the outdoor socket off from the kitchen, which is a small extra.

Power to a shed, workshop or garden room

Anything more than a socket on the house wall needs its own supply run out from the house.

That usually means:

• Armoured cable from the consumer unit, buried at a safe depth or clipped along a wall or fence where that suits better
• Its own protection at the house end
• A small consumer unit in the outbuilding with circuits for lights and sockets
• Testing, the certificate, and building control notified, because a new circuit outside is notifiable work in Wales

What decides the price is the trench, not the cable. Across a lawn it is a morning. Under a patio, through a rockery or across a drive, it is a different day entirely. A garden office with heating, a hot tub, or a workshop with big tools also needs a heavier supply than a shed with a light in it, so it is priced once Ryan knows what is going in there.

The trench

The part people underestimate is the digging. A buried cable has to go deep enough that a spade or a fence post will not reach it. Across a lawn that is a morning’s work. Under a patio or through a rockery it is a different job.

You can dig the trench yourself to save money. Ask first so the route and depth are agreed, and it is checked before the cable goes in and the trench is filled.

Safety outside

• RCD protection on everything outdoors. No exceptions.
• Weatherproof fittings rated for outside, fitted so rain runs off rather than in.
• No extension leads through a window for anything permanent. Every year these cause fires and shocks that a proper socket would have prevented.

Questions people ask

Can I have an outdoor socket for an electric car?

A normal outdoor socket is not designed to charge a car every night for hours at a time. A dedicated charger is. See EV charger installation cost.

Can the garden room run off an extension lead for now?

Not safely, and not for long. A lead is not rated for heaters or permanent use, and it is a trip and water hazard. If budget is the issue, a supply now with just a couple of sockets can be added to later.