On most kitchen and extension jobs, the electrician is in and out at two points: first fix, before the plasterer; and second fix, at the end. Between those two visits, everything gets covered up. If a socket's in the wrong place, or there's no power where the island ended up, fixing it means cutting into new plaster.

The answer is to plan the electrics properly before the builders start. Here's what to think about.

Start with how you'll use the space

Walk through a normal day in the new room:

Where will you make coffee? Charge phones? Plug in the hoover?
Where will people sit? Where will the TV go, if there is one?
Will someone work from the kitchen table?
Where will you need light: on the worktop, over the table, in the corners?

It sounds obvious, but it's the step most people skip.

Kitchen appliances

Every appliance needs a suitable supply. Common ones:

Hob and oven: an induction hob and an electric oven usually need dedicated circuits sized for their load. Check the appliance specs early.
Dishwasher, washing machine, tumble dryer: usually fed from sockets or fused connection units, ideally with isolation switches you can reach above the worktop.
Fridge-freezer: think about whether it's on a circuit that won't trip with something else.
Extractor hood
Boiling water tap, wine cooler, built-in coffee machine: easy to forget, awkward to add later.
Island: sockets in an island need power run under the floor before the floor is laid.

Get the appliance list and kitchen plan to your electrician before first fix.

Sockets

You can't really have too many sockets in a kitchen. Think about:

Plenty along the worktops, spaced sensibly
Sockets in the island
USB-charging sockets where useful
Sockets behind the TV, at the desk, by the sofa
A socket in a cupboard for the hoover or router

Lighting

Good kitchen and extension lighting is usually layered:

General lighting: downlights or pendants
Task lighting: under-cabinet lights over worktops
Feature lighting: pendants over an island or dining table
Mood lighting: plinth or wall lights

Plan the switching too. Having the lights over the island on a separate switch from the ceiling lights makes a big difference. Dimmers need compatible fittings.

If the extension has a rooflight or lantern, think about how the room will be lit at night.

Heating and underfloor

If you're putting in electric underfloor heating, it needs its own circuit and thermostat. Wet underfloor heating also needs power for the manifold and controls. Make sure your electrician and plumber are talking.

Outside

An extension is a good moment to add:

External sockets for the garden
Outdoor lighting
Power for a garden room or shed
Provision for an EV charger on the drive

Running a cable while the walls are open is far easier than doing it later.

Is your consumer unit up to it?

Adding a kitchen full of appliances and an extension's worth of circuits puts more load on your installation. Your electrician will check:

Whether the existing consumer unit has space and suitable protection
Whether the supply to the house is adequate
Earthing and bonding

Sometimes a consumer unit upgrade is needed as part of the job. It's better to know this at the start.

Smoke and heat alarms

Scotland has specific requirements for interlinked smoke and heat alarms in homes. A kitchen usually needs a heat alarm rather than a smoke alarm. Extensions and alterations should keep the alarm system compliant. Your electrician can advise.

Timing on site

Planning: layout and appliance list agreed
First fix: cables run after the structure is up, before plastering
Plastering
Kitchen fitting
Second fix: sockets, switches, lights connected and tested
Certification

Let the builder and electrician agree when first fix needs to happen. A late first fix holds up the plasterer; a rushed one leads to mistakes.

Building warrant and certification

In Scotland, extensions generally need a building warrant. The electrical work forms part of that and needs to meet building standards and the wiring regulations. On completion, you should receive an Electrical Installation Certificate, and building standards will want evidence that the electrical work complies.

Cost

We don't publish set prices because every kitchen and extension is different. The cost depends on the number of circuits and points, the appliances, lighting design, any consumer unit upgrade and the construction of the building.

FAQ

When should I involve the electrician in my extension?

As early as possible, ideally when the kitchen layout and appliance list are being finalised and before first fix.

Do I need a new consumer unit for my extension?

Not always. The electrician will check whether the existing one has capacity and suitable protection.

Can I have sockets in a kitchen island?

Yes. The power needs to be run under the floor before the floor is finished, so plan it early.

Does an induction hob need a special circuit?

Induction hobs often need a dedicated circuit sized for their load. Check the manufacturer's specification.

What certificate will I get?

An Electrical Installation Certificate on completion. Keep it with your property documents.

Send your plans through the contact form, or see our electrical installation services.

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Electrics for a New Kitchen or Extension: What to Plan Before the Builders Start