Indoor or outdoor infrared sauna? What to check in the UK

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Infrared saunas come in two broad kinds: indoor cabins that sit in a spare room, garage or garden room, and weatherproof outdoor cabins that stand in the garden. The heat works the same way. What differs is the electrics, the space, getting it in place, and whether planning rules come into it.

1. Power supply

A standard UK socket is fused at 13 A. At 230 V that’s about 3 kW (230 V × 13 A = 2,990 W), so anything rated much above that can’t sensibly run from a plug.

• Indoor models are often rated well under that. The four indoor cabins Gravity Wellness lists are rated at 1,450–1,750 W, and one is described as using a standard 3-pin UK plug.
• Outdoor models can draw more. Gravity’s two outdoor cabins are listed at “up to 4.5 kW” while also being described as plug-powered. Those two statements need explaining before you buy, so ask the retailer exactly what supply the model needs.
• Outdoors, a socket should be weatherproof and RCD-protected, and an electrician should confirm it suits the load. Don’t use an extension lead.
• New circuits in England are notifiable work under Part P of the Building Regulations, so use an electrician who can certify the work. See base, electrics and site preparation.

2. Space and access

Using the sizes Gravity lists (width × depth × height), as an example of the range:

• Indoors: check ceiling height, the floor (level, and able to take the weight), and the route in, including doorways, stairs and landings. Cabins usually arrive as flat panels, but the largest panel still has to get through.
• Outdoors: you’ll need a firm, level, free-draining base the full size of the cabin, plus room to walk round it. Measure gates and side passages on the way in.

3. Planning

An indoor cabin inside your house isn’t an outbuilding, so the garden-building rules below don’t apply to it. If your home is listed, ask your council before any work that involves fixings or new wiring.

In England, a garden sauna usually counts as an outbuilding and is often allowed under permitted development, without a planning application. The Planning Portal’s limits include:

• no outbuilding forward of the principal elevation (usually the front of the house);
• a maximum height of 2.5 metres if it’s within 2 metres of a boundary;
• no more than half the land around the original house covered by additions or other buildings;
• different rules for listed buildings and designated land such as conservation areas and National Parks.

Both Gravity outdoor models are listed at under 2.5 metres tall (2,150 mm and 2,100 mm), but check the height of the model you choose, including any base. Scotland, Wales and Northern Ireland have their own rules. If in doubt, ask your local planning authority before you buy.

4. Which suits you?

• Indoor suits you if you have a spare room or garage with the headroom, you want the simplest electrics, and you’d rather not deal with a base or weather.
• Outdoor suits you if you want it out of the house and have a level spot near a suitable supply, and you’re happy to plan a base and possibly a new circuit.

Either way, Gravity’s saunas are made to order with about a 60-day lead time and limited cancellation, as the retailer states, so settle the space and power questions before you pay. Our Gravity Wellness guide lists all six models, and barrel, cabin or infrared? covers how infrared differs from a traditional sauna.

Health

We don’t make health claims. If you have a medical condition, are pregnant or take medication, speak to your GP before using any sauna.