Make Your Outdoor Space More Practical With a Safe Socket Installation

An outdoor socket is one of the most useful additions you can make to a house, and one of the easiest to get wrong. Three things decide whether the job is done properly: whether the work needs notifying to building control, whether the socket has 30 mA RCD protection, and whether the enclosure is actually rated for the weather it will sit in. Get those three right and the rest is detail.

Regulation numbers refer to BS 7671:2018+A2:2022, the IET Wiring Regulations. Part P references are to the Building Regulations for England unless Wales is specified. Sources are listed in full at the end.

Do you need permission? England and Wales are not the same

This is the single most misunderstood point about outdoor sockets, and the answer depends on which side of the border you are on. Most guidance online still repeats the pre 2013 position, which has not been correct in England for over a decade.

Part P of the Building Regulations covers electrical work in and around dwellings. The IET is clear that the garden is in scope.

Being in scope and being notifiable are different things. In England, the 2013 revision narrowed the list of notifiable work sharply, and outdoors stopped being a special location. Wales did not follow.

What BS 7671 requires

Two requirements do most of the work outdoors, and neither is optional.

1. A 30 mA RCD, without exception in practice

Regulation 411.3.3 requires additional protection by a 30 mA RCD for socket outlets rated up to 32 A. It also names outdoor use specifically, requiring the same protection for mobile equipment rated up to 32 A intended for use outdoors. A garden socket is exactly the case the regulation was written for: bare feet, wet grass, a mower cable that has been run over twice.

There is a documented exception for certain socket outlets, but it requires a risk assessment carried out with the involvement of a skilled person, supplied with the installation certificate. It does not apply to a domestic garden.

2. The right RCD type, which is no longer Type AC

Under Regulation 531.3.3, Type AC residual current devices are only to be used to serve fixed equipment where the load is known to contain no DC components. Type A is the minimum for general purpose domestic circuits. Outdoor sockets feed exactly the loads that rule out Type AC: battery chargers, pressure washers with electronic controls, hot tub pumps, patio heater controllers and increasingly EV charging leads.

Choosing the socket: what the IP number actually means

IP stands for Ingress Protection, defined in BS EN 60529. The first digit is protection against solids, the second is protection against water. Higher is not always necessary, but outdoors it usually is.

Weatherproof sockets and enclosures we stock

All of the sockets below are IP66 rated, which is the specification discussed above for an exposed position. The two Timeguard items are for the cable side of the job rather than the socket itself, and are useful where a run has to be jointed or a garden lighting circuit needs outlets.

BG Electrical WP22 Outdoor Socket, 13A 2 gang switched IP66£10.85 BG Electrical WP21ES Nexus Storm 13A 1 gang socket with external switch IP66£14.22 Knightsbridge OP7N 13A 1 gang DP switched socket with neon, black IP66£9.49 Knightsbridge OP9R remote controlled 13A 2 gang outdoor socket IP66£42.94 Click OA035AG 1 gang 13A DP switched socket IP66£9.03 Click OA840T 2 gang 13A DP switched socket with neon IP66£15.78 Hager WXPSS82 Sollysta 13A 2 gang DP switched socket IP66£28.79 Hager WXPSS81EV Sollysta 13A 1 gang switched socket for EV IP66£38.27 Timeguard WXT68JB25 outdoor junction box, 25A IP68£8.99 Timeguard WPM02 Outdoor Connect-2 mini box with strip IP66£18.35

Prices shown are correct at the time of writing and exclude VAT where applicable. Check the product page for current pricing, stock and full specification.

Where to put it

Position affects safety, convenience and how long the socket lasts. Most complaints about outdoor sockets are really complaints about siting.

Getting power to it

There are two ways to feed an outdoor socket, and the choice changes both the cost and whether the work is notifiable in England.

If the cable has to go underground

Running power to a socket on a post, a shed or a garden room means burying cable. Regulation 522.8.10 does not give a depth in millimetres. It sets a performance requirement: cable must be at a sufficient depth to avoid damage from any reasonably foreseeable disturbance of the ground.

Trade practice has settled on figures that meet that requirement in a normal garden.

How the job runs

1. Decide what it is for. A socket for a lawnmower and a Christmas light timer is a different circuit from one that will run a pressure washer, a hot tub or a workshop. Size the supply for the real intended load, not the current one.
2. Check the existing installation. The electrician confirms whether the consumer unit already provides suitable RCD protection, and what capacity the intended circuit has. This is often where a job turns out to need a board upgrade.
3. Agree the route and position. Where the socket goes, where the cable runs, and whether anything needs digging up. Agreeing this before work starts avoids the most common source of dispute.
4. First fix. Core drill through the wall on a slight outward fall so water cannot track inwards along the hole. Run and terminate the cable, fit the back box, seal the penetration properly.
5. Fit and seal the accessory. The enclosure is mounted, the gasket seated and the gland or membrane fitted correctly. A weatherproof socket fitted without its gasket seated is just an ordinary socket with a lid.
6. Test and certify. Continuity, insulation resistance, polarity, earth fault loop impedance and RCD operation. You should receive a Minor Electrical Installation Works Certificate, or an Electrical Installation Certificate for a new circuit. Keep it.

Common mistakes

• Fitting an indoor socket in a plastic box. An IP20 accessory in an outdoor enclosure is not weatherproof. The rating belongs to the assembly, not the box it came in.
• Drilling the wall dead level. A horizontal core hole lets water track along the cable into the cavity. It should fall slightly towards the outside.
• Leaving a lead plugged in permanently. The lid cannot close, so the IP rating no longer applies, and the flex degrades in UV faster than most people expect.
• Burying twin and earth in a bit of hose. Not acceptable, not compliant, and impossible to prove safe later. Use armoured cable or a properly specified duct system.
• Spurring a heavy load off a lighting circuit. Convenient at the time, and comprehensively wrong. Load and protective device rating have to match the cable.
• Assuming any RCD will do. A Type AC device on a circuit feeding modern electronics can be desensitised by DC components and may not operate as intended.

What to ask for when you get a quote

• Is this a spur or a new circuit? It changes the price, the capability and whether the work is notifiable.
• What IP rating is the accessory? IP66 for exposed positions, IP65 where genuinely sheltered.
• What RCD protection, and what type? 30 mA, Type A as a minimum, ideally a dedicated RCBO.
• Which certificate will I receive? Minor works for an addition, full EIC for a new circuit.
• Are you scheme registered? Necessary for self certification of notifiable work in England and Wales.
• What happens if the board needs upgrading? Better to know before the work starts than halfway through.

Frequently asked questions