Pergola electrics, motorised roofs and Part P

A motorised louvred roof, a wall heater or fixed lighting all need power outdoors. Electrical installation work at home is covered by Building Regulations. Outdoors, mistakes are more dangerous because of water. Use a qualified electrician.

What Part P says (England)

Part P is the part of the Building Regulations on electrical safety in dwellings. The statutory guidance is Approved Document P on GOV.UK. The 2013 edition we read on 13 November 2026:

• Covers outdoor work. It includes installations outside the dwelling, such as fixed lighting attached to outside walls and fixed lighting in gardens, and installations in outbuildings.
• Makes some work notifiable. Installing a new circuit, replacing a consumer unit, and adding to or altering circuits in a special location (around a bath or shower, or a room with a swimming pool or sauna heater) must be notified.
• Notifiable work has to be certified. Either a registered competent person self-certifies, or a registered third-party certifier or building control body approves it.

GOV.UK's competent person scheme page explains that registered installers can self-certify, and points to the Electrical Competent Person Register to find one.

A new circuit from the consumer unit out to a pergola is notifiable. A registered electrician will deal with the notification and give you a certificate.

Wales, Scotland and Northern Ireland have their own building regulations. Ask a local registered electrician.

RCD protection

Electrical Safety First's garden safety advice says to use a residual current device (RCD) with all outdoor electrical equipment, and a plug-in RCD if your consumer unit does not have one. Only use outdoor-rated extension leads and connectors. A permanently installed pergola supply should be designed by your electrician with suitable protection.

Motorised louvred roofs

• Supply. Sunnier's Pergola Classic page, read on 13 November 2026, says its motor needs a 230 V supply and recommends a qualified electrician. Ask your maker whether theirs is plug-in or hard-wired.
• Where the cable goes. Often up through a post. Agree the route with the electrician before the base is laid, so a duct can go in.
• Rain sensors and remotes. Ask the maker what happens in a power cut, and how to close the roof manually.
• Warranty. Motor and electronics warranties are often shorter than the structural warranty. One page we read listed two different warranty terms. Ask the maker which applies.

Heaters and lighting

• Electric heaters draw a lot of power. Your electrician will size the circuit to the heater's rating.
• Follow the heater maker's clearances to roofs, louvres and fabric. See side screens, heaters and lighting.
• Plug-in festoons on an RCD-protected outdoor socket need no new circuit. Fixed lighting wired in does.

What to ask your electrician

1. Are you registered with a competent person scheme, and will you notify the work and give me a certificate?
2. What protection will the outdoor circuit have?
3. Where will the cable run, and does it need a duct under the base?
4. Can the circuit take the heater, the motor and the lights together?
5. Where will the isolator be?

Can I wire a pergola myself?

Notifiable work done by someone who is not registered has to be approved by a building control body instead. Outdoor electrics are dangerous. Use a qualified, registered electrician.

Is a plug-in motor notifiable?

Plugging an appliance into an existing outdoor socket is not installation work. Installing a new outdoor socket on a new circuit is notifiable. Ask your electrician.