Garden Rooms

Garden Room Electrics: What You Actually Need and How It Works

Garden rooms, home offices and studios have become one of the most popular home improvements since 2020 — and the electrics are one of the most frequently misunderstood parts. Here's a clear guide to what's involved, what's required, and why running an extension lead isn't the answer.

Why can't I just use an extension lead?

Extension leads running from the house are a temporary solution, not a permanent electrical installation. They're unprotected from ground faults, not rated for outdoor/damp conditions and create a trip hazard. They also won't support the loads that most garden rooms require — heating, lighting, computer equipment and monitors can easily exceed what a domestic extension lead is safely rated for. More practically, any building insurance or planning condition will typically require a proper electrical installation.

What's typically included?

• Armoured underground cable from your house consumer unit to the garden room (buried at the correct depth with cable protection)
• Sub-consumer unit inside the garden room with RCD protection and the relevant circuit breakers
• Sockets — typically 4–8 double sockets depending on use
• Lighting circuit — usually LED downlights or surface-mounted fittings
• Heating circuit (if electric heating is planned — underfloor or panel heaters)
• Data/network provision — often installed at the same time
• External IP-rated sockets or lighting if required on the outside of the building

Is it notifiable work?

Yes. Installing a new circuit from your main consumer unit to an outbuilding is notifiable under Part P of the Building Regulations. It must be carried out by a Part P-registered electrician who self-certifies, or notified to building control. You'll receive an Electrical Installation Certificate on completion.

Does my consumer unit need upgrading first?

It depends. If your current consumer unit is full (no spare ways for additional circuits), has no RCD protection, or is older than current standards, it may need upgrading at the same time. Your electrician will assess this as part of the job.

How long does it take and what does it cost?

A standard garden room electrical installation typically takes 1–2 days on site. Costs in Kent in 2026 usually run from around £800–£1,800 depending on the distance from the house, what's required inside the garden room, and whether any consumer unit work is needed.