How to Run Permanent Power to a Garden Shed or Summerhouse

A shed, summerhouse, or garden office without power is limited to daylight hours and whatever you can run off a battery. Once you add electricity, it becomes a genuinely usable space — lighting, heating, charging tools, running a laptop, or even a small fridge. Here's what to actually consider before you run power out to a garden building.

Two ways to get power outside: extension lead vs. fixed wiring

There are two realistic approaches, and which one suits you depends on how the space will be used.

A heavy-duty outdoor extension lead is the flexible option. A good IP66-rated, armoured extension lead run from an outdoor socket on the house to the shed can safely carry power for lighting, chargers, and low-draw appliances. This is a straightforward option that doesn't require rewiring, and armoured cable versions are built to be left in place semi-permanently, resisting weather, foot traffic, and general wear.

Fixed, dedicated wiring run through an armoured cable buried at the correct depth, installed by a qualified electrician, is the right choice for a garden office, a workshop with power tools, or anywhere you need higher, sustained loads (heaters, power tools, multiple outlets). This is notifiable work under UK Building Regulations (Part P) and should be certified.

If you're unsure which you need: if it's lighting, charging, and light electronics, a quality armoured extension lead is often enough. If it's heating, power tools, or anything load-heavy and permanent, get an electrician to install fixed wiring.

What to look for if you're going the extension lead route

  1. Armoured cable – rather than a standard flex lead, an armoured cable adds a layer of physical protection, so if it's going to be buried shallow, run along a fence line, or left out permanently, this matters far more than it does for a lead you coil up after a weekend BBQ.
  2. IP66 rating minimum – anything exposed to the weather for extended periods needs full protection against wind-driven rain, not just splashes.
  3. RCD protection – non-negotiable for anything running to an outdoor building. It cuts power instantly if there's a fault, which matters even more once the cable is out of sight and less likely to be checked regularly.
  4. Cable length and gauge – running power a long distance means voltage drop becomes a real consideration. Don't just buy the cheapest lead that reaches; check it's rated for the length and the load you intend to put through it.
  5. Cable glands where the cable enters the building – a properly sealed entry point (IP68-rated cable gland) stops water tracking in along the cable itself, which is one of the most common failure points in DIY setups.

A few things people get wrong

  • Running cable along the surface of a lawn — even armoured cable left exposed on grass will eventually get damaged by mowing, foot traffic, or simply UV degradation over years. Bury it (at the correct depth, in ducting) or run it along a fence/wall where it's protected.
  • Daisy-chaining multiple extension leads — every joint is a weak point and a moisture risk. One continuous, correctly-rated lead is always safer than several joined together.
  • Ignoring the load — a lead rated fine for a phone charger and a lamp will not be fine for a fan heater and power tools running at once. Check the amp rating against what you'll actually plug in.
  • No RCD — this is the single most important safety feature for outdoor power and it's often skipped to save a few pounds.

Quick checklist before you start

  • Decide: extension lead or fixed wiring, based on load and permanence
  • Choose IP66-rated, armoured cable for anything semi-permanent or exposed
  • Confirm RCD protection is included
  • Plan the cable route — buried, ducted, or wall-run, never left loose across a lawn
  • Check the amp rating covers everything you intend to run at once
  • For fixed wiring, use a qualified, certified electrician

The bottom line

For most sheds and summerhouses used for lighting and light electronics, a properly rated armoured outdoor extension lead is a practical, cost-effective way to get permanent power outside without the cost of full rewiring. Take a look at our range of armoured outdoor extension leads built for exactly this kind of permanent outdoor use.

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