Do I need planning permission for a home EHU point?

You do not usually need planning permission for a home EHU socket, but the electrical work is notifiable under Part P of the Building Regulations in England. It must be done by a registered competent person, or notified to your local authority building control department. The caravan or motorhome itself may need permitted development rights depending on how long it is parked.

Can I use a standard 13 A socket instead of a commando socket?

No. Caravan and motorhome hook-up leads use IEC 60309 16 A commando plugs and cannot safely connect to a standard 13 A BS 1363 socket. Using adapters to bridge the two creates a mismatch in circuit protection and defeats the purpose of a dedicated hook-up point.

What cable size do I need for an EHU circuit?

For most domestic EHU installations with a run under 20 m, 2.5 mm² T&E cable protected by a 16 A MCB or RCBO is sufficient. For longer runs or where the cable is clipped directly to an insulating surface, you may need 4 mm². The voltage drop must stay within 3% under BS 7671 — calculate this for your specific run length.

How to Install a Home Electric Hook-Up (EHU) Point (UK)

Helpful video reference. This UK video — "Home Electric Hook Up Point For A Motorhome, Caravan Or Campervan" — features qualified electrician Glyn Beckwith fitting an EHU point to the outside of a garage. Glyn covers the socket choice, cable routing and RCD protection in a practical, UK-specific way. The video was filmed on a real domestic property, which makes the context easy to relate to.

Before you start. Installing a home EHU point involves running a new circuit from the consumer unit. In England and Wales this is notifiable work under Part P of the Building Regulations. The job must either be done by a registered competent person (who can self-certify) or be notified to your local authority building control department. Do not connect a commando socket to an existing ring main or to an extension lead — it needs a dedicated circuit with appropriate protection.

1. Choose the right location

Position the socket where the vehicle will consistently park. Aim for a spot that minimises the length of the EHU cable your motorhome or caravan will need to reach. Most hook-up leads are 10 m or 25 m — a socket close to where the vehicle parks keeps the cable tidy and reduces volt drop at the vehicle end.

Avoid positions where water is likely to pool around the socket enclosure, and try to mount it at a height that is practical to reach but does not get knocked by a reversing vehicle. A position on a wall above 600 mm from the ground is usually sensible.

2. Understand the circuit requirements

A home EHU socket needs its own dedicated circuit from the consumer unit. The circuit should be protected by a 16 A MCB or RCBO. Under BS 7671, all outdoor socket circuits must have 30 mA RCD protection — an RCBO covering the circuit is the cleanest solution, but a dual RCD board arrangement can also work.

A standard caravan site hook-up point supplies 16 A, which gives roughly 3.7 kW. Your motorhome or caravan should never draw more than this without tripping the supply breaker. Most caravans draw considerably less in normal use.

3. Select the right socket

You need an IEC 60309 (BS EN 60309-2) 16 A, 2P+E, 230 V commando socket. These are rated at IP44 minimum, which means splash-proof from any direction. For positions exposed to direct rain or pressure-washing, IP67 (submersion-rated) is better. The socket should be mounted in a weatherproof enclosure with a hinged or screw lid that closes properly when the lead is not connected.

Colour-coding: the 16 A, 230 V single-phase commando plug and socket are blue. Do not confuse these with red (16 A, 110 V site supply) or yellow (16 A, 110 V centre-tapped to earth), which are used on construction sites and are not compatible.

4. Size the cable

For a run up to around 20 m from the consumer unit in a domestic property, 2.5 mm² two-core and earth (T&E) cable protected by a 16 A device is generally adequate. For longer runs, or where the cable is clipped to an insulating surface or enclosed in insulation, you may need 4 mm² to keep voltage drop within the 3% limit set by BS 7671.

If you are unsure, ask the electrician to confirm the volt drop calculation for your specific installation before ordering cable.

5. Plan and run the cable route

Route the cable from the consumer unit to the socket location by the most practical path. Where the cable runs along the outside of a building, fit it in UV-resistant conduit or clip it in the safe zones under BS 7671 (within 150 mm of a wall or ceiling corner). Avoid areas where it could be damaged by vehicles, tools or lawnmowers.

Where the cable passes through an external wall, use a proprietary wall entry seal or stuff the hole with expanding foam around the cable to prevent draughts and pests entering. Seal the entry on both sides if possible.

6. Wire the commando socket

Connect brown to L (line), blue to N (neutral), and green/yellow to E (earth). These are the standard harmonised cable colours used in UK wiring since 2004. Tighten each terminal to the torque specified by the socket manufacturer — commando sockets typically specify 2.5 to 3 Nm. Overtightening can crack the terminal block; undertightening causes loose connections that overheat over time.

Ensure the cable entry into the enclosure is sealed properly using the cable gland supplied with the socket or a suitable waterproof grommet. Close the lid and check the hinges and seals are in good order.

7. Test before use

Before energising the circuit, check continuity on each conductor and insulation resistance between conductors and between conductors and earth. These tests confirm there are no wiring errors and that the cable insulation has not been damaged during installation.

Restore power and use a socket tester to verify correct polarity (L and N the right way round) and that the earth is present. Press the RCBO or RCD test button to confirm the protection device trips correctly. Connect a known-good appliance and check it runs normally before plugging in the caravan or motorhome.

Stop and call an electrician if: your consumer unit has no spare capacity for a new circuit, the cable run is very long and you are unsure about volt drop, the socket position is in a location subject to flooding or heavy water ingress, or you are working near gas pipes or service entry points where the risk of accidental damage is higher.

When to call us

This is a job where the electrical side is not complicated, but it is notifiable Part P work in England and Wales — which means it needs a qualified electrician to certify it regardless of who does the physical work. Richard is happy to quote for EHU point installation in Sandwich and the surrounding east Kent area, supply the socket and cable, and issue the certificate.

Want an EHU point fitted in east Kent?

Richard installs home electric hook-up points for caravans and motorhomes. Call or message for a quote — usually a half-day job including the certificate.

Contact Richard

How to install a home electric hook-up point