What's usually involved
- A suitable outdoor-rated socket with RCD protection
- For sheds, workshops and garden rooms, usually a new circuit from the consumer unit, run in cable that's suitable for burial or protected along its route
- Sometimes a small consumer unit in the outbuilding
- Testing and certification when it's finished
Adding a new circuit, or a new outdoor circuit, is notifiable under Approved Document P. A registered installer can self-certify the work and notify building control for you; otherwise you need building control approval.
Planning a garden room or workshop?
Think about what you'll run in there (heaters, power tools, a kettle) as this affects the size of the supply. If you might add an EV charger later, mention it at the same time.
Safety first
Don't power an outbuilding with an extension lead through a window or door. Keep electrics away from hoses and ponds, and use an RCD with outdoor tools. See Electrical Safety First's garden safety advice.
When to call an electrician
- Adding an outdoor socket
- Running power to a shed, workshop or garden room
- Existing garden electrics that trip, look damaged or let water in
Sources and further reading
- GOV.UK – Approved Document P (electrical safety in dwellings)
- GOV.UK – Building regulations approval
- Electrical Safety First – Garden safety
- IET – BS 7671 Wiring Regulations
General guidance only, based on the sources above. Last reviewed October 2026. It isn't a substitute for an inspection by a qualified electrician.