New build electrics, from first fix to the certificate.

What the per-plot price covers

The price covers first and second fix, the consumer unit, the testing and the certificate on a two- to three-bed plot built to a basic specification.

A bigger house or a higher specification costs more, and so do the extras people add to a new build, such as outside lighting or a car charger. Those are priced in writing from the plans.

First and second fix on a new build

First fix follows the frame. With the roof on and the internal walls up, the cables go in through the studs and joists to every back box and to where the consumer unit will be, all before the plasterboard or plaster goes on.

Second fix waits for the decorating, when the accessories and fittings are mounted and every circuit is connected. The whole installation is tested before it's switched on for the first time.

Other trades come and go in between, so I fit around the build programme.

New build electric supply

The supply to a new plot comes from the network operator, which in this part of Yorkshire is Northern Powergrid. I don't do the network operator's side of the meter, so the connection is an application you or your builder make to them.

Apply early. Northern Powergrid says the cost and timing of a new connection vary with the complexity of the work and the location of the property. The application asks for the site postcode and how the house will be heated, and a plan with the meter position marked helps.

Where the meter goes decides where the board and the main cable run can go, so it's worth settling with the drawings. For the build itself, Northern Powergrid also provides temporary supplies for building sites, before the permanent connection is made.

New build electrical certificate

In a new home every circuit is new, and under Part P a new circuit is notifiable work. When it's finished I test the installation and write the Electrical Installation Certificate, and Building Control has to be satisfied the electrics comply before it issues the completion certificate for the house.

Keep the certificate with the house documents. It describes the installation and records the test results.

Other Building Regulations that touch the wiring

Part M sets the height of switches and sockets in new dwellings so they're easy to reach, and Part L asks for energy-efficient fixed lighting.

Smoke alarms come under Part B. Every new dwelling gets them, as part of a fire alarm system to the British Standard for homes, mains-powered with a standby battery or capacitor.

Parts B and E reach the cable routes too. Where cables pass through fire-resisting floors and walls, or a wall shared with the house next door, the holes have to keep the fire resistance and the sound insulation the construction was built to give.

Under Part S, each new home with its own parking needs an electric vehicle charge point, unless the connection cost would go over a cap set in the regulations, in which case cable routes for a charger go in instead.

Part R deals with broadband. A new home has to have ducting and a termination point ready for a gigabit connection, so it pays to decide where the router will sit, and which rooms want a wired data point, before first fix.

Planning the electrics on a self-build

On a self-build you decide where everything goes, and the architect's drawings don't always show it. A socket, switch and light plan drawn room by room before first fix saves cutting into new plaster later.

Outside lights and a garden socket are easier to cable while the ground is still open.

You deal with me at first fix, second fix and the final test, which helps when a plan changes halfway through the build.

Garages and outbuildings on a new plot

Part P covers a detached garage or a garden room wired from the house, just as it covers the house. Approved Document P names sheds and greenhouses among those outbuildings.

The cable to it is best laid before the drive and the garden go down, so power to a garage or outbuilding can be finished at second fix with the house.

Conversions and loft rooms

Barn and stable conversion electrics start from an old farm building rather than a bare plot, so the existing supply and earthing are checked before anything is quoted.

A room in the roof of an existing house is extension work, and wiring a loft conversion has its own Building Control points.