Electrical installation: new sockets, lights and circuits

A few extra sockets can often be added to an existing circuit, if that circuit is in good condition and has capacity for more load. The electrician tests it before extending it. If the circuit already serves a kitchen full of appliances, or the tests show a fault, a new circuit from the consumer unit is the better option.

New circuits are needed for larger loads such as an electric cooker, an electric shower, an outbuilding or an EV charger, and often for a new extension or a converted loft. A new circuit is notifiable work under Part P in England and Wales. An electrician registered with a competent person scheme self-certifies it; otherwise Building Control must be involved before the work starts.

Whether a new circuit is possible also depends on the consumer unit. If it has no spare ways or no suitable protection, the electrician may recommend replacing it first.

Rooms with a bath or shower are special locations in the wiring regulations, divided into zones around the water. What may be installed, and with what protection, depends on the zone, which is why a shaver socket may be allowed where an ordinary socket is not. Altering circuits in these rooms is notifiable in England. In Wales, kitchens and outdoor installations are also treated as special locations.

Outdoor sockets, garden lighting and power to a shed or garden office need weatherproof equipment, protection by residual current devices and cable that is protected against damage, usually armoured cable buried at a suitable depth or run along a wall. A supply to an outbuilding also raises the question of earthing, which depends on your supply type. It is not a job for a spare evening with an extension lead.

In an extension or a renovation, electrical work happens twice. First fix runs cables and fixes back boxes while walls and ceilings are open, before plastering. Second fix fits the sockets, switches and fittings once decorating is nearly done. Between the two, the plasterer, kitchen fitter and builder need to know where everything goes.

Walk round with the electrician before first fix and mark socket heights, switch positions, the television wall, outside lights and where the kitchen appliances will stand. Moving a socket after plastering means chasing the wall again. For lighting, decide early on dimmers, two-way switching and whether you want downlights, which need fire-rated fittings or covers where they go into ceilings that form a fire barrier.

• a list of rooms with the number and type of sockets, switches and fittings wanted
• a sketch or photos showing positions, and whether walls are solid or stud
• the age of the existing wiring and consumer unit, with a photo of the consumer unit
• for outbuildings: distance from the house and the route the cable could take
• for extensions: drawings, and the builder's programme for first and second fix
• who supplies light fittings and switches, you or the electrician

Adding socket after socket to an old circuit without testing it; buying fittings online that are not rated for bathrooms or outdoor use; not planning enough sockets and relying on extension leads; and skipping the certificate. After new work you should receive an Electrical Installation Certificate or Minor Works Certificate, and for notifiable work the Building Regulations compliance certificate. A buyer's solicitor will ask for them.

Once you have confirmed your mobile number by code and your email by link, electricians in your area see the job without your name or contact details. One firm can buy it, and then it is removed from sale. The electrician pays Offrano; for you the service is free.

Before the firm sees your details, you get its name, address and phone number by email. If nobody buys the request within 21 days, it is withdrawn, and you can always ask other electricians yourself. Offrano only checks that buyers are registered businesses; check competent person scheme registration on the official register before notifiable work starts.