How much does it cost to wire a detached garage?

Every job is different depending on the distance from the house, number of circuits, and site conditions. A typical single-garage installation with lighting and sockets is scoped on site. I provide free, no-obligation estimates after a site visit.

What cable is used to run power to a detached garage?

Steel wire armoured (SWA) cable is the standard for running power to a detached garage. It provides its own mechanical protection, is weather-resistant, and is suitable for external surface-mounted or underground runs. Standard domestic cable is not suitable for outdoor or underground use without additional protection.

Does a detached garage need its own consumer unit?

Yes. A detached outbuilding should have its own consumer unit (or small distribution board) with individual circuit protection. This provides local isolation and separate MCBs for each circuit, typically one for lighting and one for sockets.

Do I need a certificate for garage electrics?

Yes. A new electrical supply to a detached garage is notifiable under Part P of the Building Regulations. An Electrical Installation Certificate (EIC) must be issued on completion. As an NICEIC Approved Contractor, we self-certify all installations.

Before & After: Wiring a Detached Garage From Scratch

One of our most popular jobs is supplying power to detached garages and outbuildings. This one is a good example of what’s involved, and the difference it makes.

The Starting Point

This detached garage had nothing more than a single pendant light hanging from the ceiling. No sockets, no consumer unit, no proper electrical supply. The customer wanted to actually use the space, and for that, they needed proper power.

What We Installed

We ran a steel wire armoured (SWA) cable from the house, routing it neatly along the external wall at low level and through to the garage. SWA is the correct cable for this kind of external run. It’s tough, weather-resistant and provides its own mechanical protection.

SWA cable routed neatly along the external brick wall from house to garage

Inside the garage, we installed a dedicated BG consumer unit with a 100A main switch and individual MCBs protecting separate circuits:

B6, lighting circuit
B16, socket circuit

Everything is surface-mounted in white conduit, keeping it tidy against the exposed brickwork.

Inside the BG consumer unit, 100A main switch, B16 and B6 MCBs, tidy wiring

The Result

A fully functional garage with proper lighting and double sockets, its own dedicated supply and individual circuit protection. Tested, certified and labelled with the installation date and next recommended inspection.

Finished garage installation. BG consumer unit, white conduit, light switch and double socket on brick wall

Close-up of the consumer unit with Bright Sparks of York sticker and BS 7671 inspection label

What Does a Garage Power Supply Cost?

Every job is different depending on the distance from the house, the number of circuits and the existing supply. I provide free, no-obligation estimates, just get in touch and we’ll come and have a look.

Key details:

Cable: Steel wire armoured (SWA), external surface-mounted run

Consumer unit: BG with 100A main switch, B6 and B16 MCBs

Circuits: Lighting (6A) and sockets (16A)

Containment: Surface-mounted white conduit on brickwork

Certification: Electrical Installation Certificate (EIC) to BS 7671

Frankie Sewell
NICEIC Approved Contractor • YRLA Recognised Service Provider • Bright Sparks of York

Need Power to Your Garage or Outbuilding?

Tell me what you need and we’ll give you a clear estimate based on the actual cable route. No obligation.

Get in Touch WhatsApp Me Call 01904 530 735

Before & After — Wiring a Detached Garage From Scratch

The Starting Point

What We Installed

The Result

What Does a Garage Power Supply Cost?

Need Power to Your Garage or Outbuilding?

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