Cost to Wire a Garage or Outbuilding
How much does it cost to run electricity to a garage or outbuilding?
In the UK, the cost to wire a garage or outbuilding typically ranges from £500 to £3,000, depending on a number of variables. Adding lighting to your garden room, or powering tools in a detached shed, you’ll need to consider the cost of wiring the space. Whether it’s for basic lighting and sockets or heavier electrical loads like power tools or EV chargers, properly installing electrics in a garage or outbuilding is essential for safety, compliance, and convenience.
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User submitted wiring prices
Below are prices submitted by WhatPrice users for either quotations received or work done for garage or outbuilding electrical work, these are to be used as a guide only for costs involved. We always recommend sourcing multiple quotes from qualified electricians.
| Job type | Description | Price | Units | Region |
|---|---|---|---|---|
| Outbuilding power | Power to the garage, 3 sockets, 2light | £2,500 | Total price | South East |
| Outbuilding power | connecting from main to outbuilding | £2,100 | Total price | West Midlands |
| Outbuilding power | Two new outside lights on separate switches. Light and power into external garage (separated from house) with underground cabling. New consumer unit for RCD protection. | £1,090 | Total price | South West |
| Outbuilding power | install armoured cable to outbuilding, 25m run, 2 way RCD consumer unit with earth rod and 2 twin socket and 1 light with switch | £495 | Total price | North East |
| Outbuilding power | install swa supply to shed 10m from house, cable buried in duct under paving, install 2way consumer unit in shed, 1 light and switch, 1 socket, rcd fitted to main consumer unit, earth rod connected to shed consumer unit | £800 | Total price | East Midlands |
| Outbuilding power | Fit new 40amp mcb in consumer unit. Run 12m 4mm cable in trunking from Non RCD side of consumer unit to junction box outside kitchen. From junction box run 30m 4mm 3 core SWA in trench to outbuilding RCD 2 way steel consumer unit. Fit 6 dble metal sockets connected with 2.5 in black plastic conduit 20m. 1 metal light switch and 5ft light. Fit 1 PIR with led lamp outside connected via metal fused switch, plus installation certificate. | £2,360 | Total price | South West |
| Outbuilding power | Fit new dual RCD 10way consumer unit and run new cable to garage 10mtrs with small consumer unit fitted in garage. | £2,800 | Total price | South East |
| Outbuilding power | Wire new ring main to converted garage with 7 double sockets and one spur for heater. Wire new lighting circuit with 3 new 5 foot fittings. Upgrade water and gas bonding. | £1,250 | Total price | South East |
| Outbuilding power | This was cost of running electricity supply to outside workshop (approx 30 metres distance from house)- 3 double sockets 2 seperately switched ceiling lights and seperate socket for panel heater. Price includes VAT. | £758 | Total price | East of England |
What is involved in the wiring of a garage or outbuilding?
A new supply for a socket and lighting circuit may need an upgrade of the current household consumer unit if the current unit is full, if not then a suitably sized MCB can be installed and steel wire armoured (SWA) cable (or a cable run in conduit) fed to the external building.
Once a supply cable is in place the installation of a mini consumer unit and electrical circuits can take place. This type of work is notifiable under Part P of the Building Regulations and an electrical certificate supplied.
Should you want to run a power cable to an external garage or outbuilding you’ll more than likely need the help of a qualified electrician.
So how much should you expect to pay and what factors influence the final cost? In this guide, we’ll walk you through the typical prices, common considerations, and tips for getting the job done right.
What factors will affect the cost of wiring?
Distance from the main property
If the outbuilding is detached, you’ll need to run power from your main consumer unit often requiring armoured cable buried underground or clipped to a wall. The longer the distance, the higher the cost due to more cabling and potential trenching.
Trenching cost (if needed): £20 to £50 per metre (more if obstacles are present).
Sub-consumer unit (fuse board)
For outbuildings that require several circuits, like lighting, power sockets, and a heater, you’ll likely need a small consumer unit installed in the garage. These start around £100 but can rise depending on the number of circuits and protection needed (RCDs/MCBs).
Power requirements
If you only need lights and basic sockets, you might get away with a 16A or 20A supply. But if you’re running power-hungry tools, electric heaters, or EV chargers, you’ll need a heavier supply (32A or even 63A), and that means bigger cable sizes and possibly main board upgrades.
Use of armoured cable (SWA)
Outdoor installations require Steel Wire Armoured (SWA) cable for safety. SWA cable is more expensive and trickier to work with than standard indoor twin & earth.
- SWA cable cost: £3 to £8 per metre depending on size
Labour
Electricians typically charge £150 to £300 per day or quote per job. Expect the job to take 1 to 3 days depending on complexity.
Here’s a general breakdown:
| Type of Installation | Estimated Cost |
| Basic electrics (1-2 lights, 1-2 sockets) | £500 to £1,200 |
| Mid-range (lighting, multiple sockets, small tools) | £1,200 to £2,000 |
| High-spec (consumer unit, heating, 32A circuits) | £2,000 to £3,000+ |
These figures include materials, labour, and VAT, but can vary depending on the complexity of the work and your location in the UK.
Legal and safety requirements
It’s important to understand that wiring an outbuilding is notifiable work under Part P of the Building Regulations in England and Wales. That means:
- You must either use a Part P-registered electrician, or
- Notify your local building control office and pay for an inspection
Failure to comply can result in fines, delays when selling your home, or unsafe electrics. Hiring a registered electrician ensures the work is done safely and signed off with a certificate of compliance.
More tips to keep in mind
Plan for the future
Even if you only need a couple of sockets now, consider adding extra capacity in case you later decide to install an EV charger, electric heating, or more lighting. Adding an extra conduit or a larger cable during the initial job is cheaper than redoing it later.
Think about heating
If you plan to work in the garage year-round, electric heaters might be a must. Make sure you factor this into your load requirements.
Waterproofing and weatherproofing
Outdoor sockets, switches, and light fittings need to be IP-rated (Ingress Protection). Ask your electrician to use gear suited for damp or dusty environments.
Compare quotes
Always get 2 to 3 quotes from registered electricians. Be wary of very low prices as they might not include certification or could indicate poor quality workmanship.
Wiring a garage or outbuilding is a worthwhile investment that increases usability, safety, and potentially property value.
By understanding what affects the cost and ensuring the work is done by a qualified professional, you’ll get a safe, long-lasting installation that supports your needs whether you’re creating a living space, a workshop, or a home office.
