Garden power and outdoor sockets

Outdoor sockets

A weatherproof double socket on the house wall, fed from a circuit inside, is £100 + VAT (£120 inc VAT) where there is a circuit close by to feed it from. Each further socket on the same run costs a lot less than the first. Every outdoor socket has to be RCD protected, so if your board has no RCD on that circuit, that gets sorted first, which sometimes means a new consumer unit.

Supplies to sheds, workshops and garden rooms

Anything beyond the house wall gets its own supply: armoured cable from the consumer unit, buried to a safe depth or clipped where that suits better, its own protection at the house end, and a small board in the building with circuits for lights and sockets. A supply on its own is one price; a supply with the lighting and sockets fitted inside the building is another, and both depend far more on the trench than on the cable.

A garden office with heating, a workshop with real tools, or a hot tub needs a heavier supply than a shed with a light in it. That gets sized to what is actually going in there, which is why it is worth saying up front what you are planning, including anything you might add later.

The trench is the bit people forget

Buried cable has to be deep enough that a spade or a fence post cannot reach it, and marked so the next person knows it is there. Across a lawn that is a morning. Under a patio, through a rockery, or across a drive, it is a different job. You can dig it yourself to save money, as long as the route and depth are agreed first and it is checked before it gets filled in.

Outdoor and garden lighting

A new outdoor lighting circuit with its own switching is priced as one job, then each mains light on it is a small amount to fit on top. Low voltage lighting, run off a transformer by the house, is easier to add to and move about later, and suits path and planting lighting. Mains suits wall lights, post lights and anything that needs to be bright. There is more on choosing between them in the garden lighting guide.

Hot tubs

A hot tub needs its own circuit, its own isolator outside, and RCD protection. It is not a job for an extension lead through a window, and tubs that trip the house every time they heat are almost always on a supply that was never sized for them.

Doing it during a rewire

If a rewire is on the cards, the garden supply is much cheaper run at the same time, because the board is already open and the floors are already up.

Questions people ask

Can I run the shed off an extension lead for now?

Not safely, and not for long. Leads are not rated for permanent use or for heaters, and they are a trip and water hazard.

Does outdoor work need building control?

A new circuit outside is notifiable in Wales. It is notified through our scheme and you get the certificate.

Will the cable survive the winter?

Armoured cable buried properly will outlast the shed. It is the cheap stuff clipped along a fence that fails.