Electrical work for extensions, conversions and shop fit-outs

As early as you can: ideally while the drawings are being finished, and certainly before first fix. Moving a socket on paper costs nothing, while moving it after plastering means cutting into a new wall. Starting early also leaves time to deal with the consumer unit or the supply if they need work.

It depends on what is there now and what you are adding. We look at whether the board has space and suitable protection for new circuits, whether the earthing is adequate, and whether the supply can carry the extra load, especially with electric cooking or underfloor heating. Sometimes the new circuits connect into the existing board; sometimes the board needs replacing, or a separate board for the extension makes more sense. That is what the check before the quote is for.

Contact your network operator and energy supplier as soon as the plans are drawn. The cut-out (main fuse) and the cable that feeds it belong to the network operator, and the meter belongs to your energy supplier or its meter operator, so only they can move them, and it takes time to arrange. Moving the consumer unit and the wiring from the meter onwards is work on your own installation, which we can quote for alongside the extension.

In England, a new circuit in a home is notifiable under Part P of the Building Regulations, and many extensions and conversions add one. Notifiable work is either done by an installer registered with a competent person scheme, who notifies it through the scheme, or notified to building control before work starts, often as part of the project’s own building regulations application. Work that is not notifiable still has to meet the Building Regulations. Ask us and your building control body how the electrical work will be covered before first fix.

Usually new lighting and socket circuits for the new floor. Existing lighting cables often run across the ceiling joists of the rooms below, so they need moving or protecting before the new floor goes down, and new cables have to be sized and routed with the insulation in mind. A shower room brings in the BS 7671 rules for rooms with a bath or shower. Building regulations normally expect mains-powered, interlinked smoke alarms in a loft conversion; building control will confirm what yours needs, and the wiring is planned at first fix.

Ask us before you buy. Some fittings need particular back boxes, ceiling hole sizes, drivers or ratings: fire-rated downlights where the ceiling needs them, for example, or fittings suitable for a bathroom or outdoors. We need the details before first fix, and the quote should say who is supplying what.

The order of work is similar, but the starting point changes. The landlord may have requirements for tenant works, the shopfitter’s layout fixes where counters, displays and signage go, and the equipment list sets the load. Whether the premises need emergency lighting, and where, follows from the fire risk assessment, so it helps to have that settled before first fix. It also helps to plan the work back from the date you want to open.

BS 7671 requires the certificate to be given to the person who ordered the work, so if your builder engaged the electrician, it goes to them. Ask your builder to pass it on at handover with the rest of the completion paperwork: you need it for your records, when you sell, and when the installation is next inspected.