The short answer
Garden room power is usually supplied by an armoured cable run from the house consumer unit to a small consumer unit in the room, and this work must be done or certified by a registered electrician under Building Regulations Part P. That gives you sockets, lighting and a heater point. For internet, the most reliable options are a wired Ethernet cable run alongside the power, a mesh Wi-Fi node, or a dedicated outdoor access point — a wired connection is best for video calls. Electrical work is the one part of a garden room you must not treat as optional or DIY.
A garden room without reliable power and internet is just a shed with nice windows. Getting both right is straightforward when done properly, but the electrics in particular are governed by law: connecting a new circuit to your home’s supply is notifiable work and must be certified. This guide explains how power and connectivity are installed, what is legally required, and how to make sure your video calls do not drop out halfway down the garden.
Electrics & Wi-Fi at a glance
- Power supply Armoured cable from house
- Certification Part P, registered electrician
- Typical fit-out Sockets, lights, heater point
- Best internet Wired Ethernet run
- Wireless options Mesh node / outdoor AP
- DIY connection Not permitted
How the power is connected
The standard method is a steel-wire armoured (SWA) cable buried in a trench from the house to the garden room, feeding a small consumer unit inside. From there the electrician wires sockets, lighting, and usually a fused point for a heater and provision for networking. The cable size and protection are calculated for the load and distance. Crucially, this is notifiable work under Building Regulations Part P: it must be carried out or certified by a registered electrician, who will issue an electrical installation certificate. This protects you, satisfies insurers, and avoids problems at resale. It is included in any proper supplied-and-fitted quote.
| Internet option | Reliability | Best for |
|---|---|---|
| Wired Ethernet run | Highest | Video calls, working |
| Mesh Wi-Fi node | Good | Browsing, light work |
| Outdoor access point | Good–high | Longer gardens |
| Powerline adapter | Variable | Backup / simple needs |
| Mobile / 4G–5G router | Variable | No house link possible |
Getting reliable internet down the garden
Wi-Fi from the house router rarely reaches the bottom of the garden reliably, especially through an insulated, foil-backed wall. The most dependable fix is to run a network (Ethernet) cable in the same trench as the power cable while the ground is open — cheap to do then, expensive to retrofit. That feeds a wired connection or a local access point in the room, giving solid speeds for video calls. A mesh node or dedicated outdoor access point is a good wireless alternative; powerline adapters and 4G/5G routers work but are more variable. Plan this before the trench is dug, because the cheapest moment to add an Ethernet run is during the build.
Why electrics are never a DIY shortcut
It can be tempting to save money by running an extension lead or wiring it yourself, but connecting a garden room to your home’s supply is notifiable work under Part P and must be certified by a competent person. Uncertified work is unsafe, can invalidate your home insurance, and routinely causes problems when you sell. Whether you buy supplied-and-fitted or kit, budget for a registered electrician. If the room includes a bathroom, additional electrical-zone rules apply. This is general information; all electrical work must comply with Building Regulations Part P and be certified.
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Frequently asked questions
How is a garden room connected to electricity?
Usually by a steel-wire armoured cable buried from the house consumer unit to a small consumer unit in the room, feeding sockets, lights and a heater point. The work must be carried out or certified by a registered electrician under Building Regulations Part P.
Do I need a certified electrician for a garden room?
Yes. Connecting a new circuit to your home supply is notifiable work under Part P and must be done or certified by a registered electrician, who issues an installation certificate. DIY connection is not permitted and can invalidate insurance.
How do I get Wi-Fi in a garden room?
The most reliable option is a wired Ethernet cable run alongside the power cable, feeding a wired point or local access point. Mesh Wi-Fi nodes and outdoor access points are good wireless alternatives. Plan a data run before the trench is dug.
Can I just use an extension lead for a garden room?
No — a trailing extension lead is unsafe for a permanent room, not weatherproof, and not a compliant supply. A garden room needs a proper, certified circuit installed by a registered electrician under Part P.
Sources & further reading
- GOV.UK / Building Regulations Approved Document P — electrical safety and notifiable work
- GOV.UK Planning Portal — outbuildings and services
- Trade and industry electrical guidance — garden room power and networking practice
This is general information, not advice for your specific property or project. All electrical work must comply with Building Regulations Part P and be carried out or certified by a registered electrician.