A two-person outdoor sauna is the most common first sauna purchase in the UK, and the one people most often get wrong — usually by underestimating the footprint, the electrical supply or the base. This guide covers the practical decisions in the order you actually have to make them.
What size is a 2 person outdoor sauna, really?
"Two person" describes seating, not comfort. Most two-person cabins give you a bench roughly 1.2m long — enough for two people sitting upright, not enough for one person lying down.
Typical external footprints:
| Style | Typical external footprint | Realistic use |
|---|---|---|
| Two-person infrared cabin | Around 1.2m × 1.1m | Two sitting, upright |
| Two-person barrel | Around 1.8m × 1.9m | Two sitting, one can recline |
| Two-to-three person cabin | Around 1.8m × 1.5m | Two comfortably, three at a squeeze |
Then add clearance. Most manufacturers specify a gap behind and to the sides for ventilation and maintenance access — commonly 30 to 50cm. A 1.8m barrel therefore wants roughly 2.8m × 2.5m of actual garden.
The advice almost everyone gives after the fact: if two of you will use it together regularly and the budget stretches, buy the next size up. The running cost difference is small. The regret about not being able to lie down is not.
Do you need planning permission for a garden sauna in the UK?
In most cases a garden sauna falls under permitted development as an outbuilding, but the conditions matter and they are not negligible:
- Single storey, with a maximum eaves height of 2.5m
- Maximum overall height of 4m for a dual-pitched roof, 3m otherwise
- Maximum height of 2.5m if within two metres of a boundary
- Not forward of the principal elevation
- Outbuildings must not cover more than half the land around the original house
Permitted development rights are restricted or removed in conservation areas, national parks, Areas of Outstanding Natural Beauty, on listed properties, and on some newer estates where they were removed by condition. Flats and maisonettes do not have them at all.
This is general guidance rather than advice on your specific property. A quick call to your local planning department before you order is free and takes ten minutes.
What electrical supply does a 2 person sauna need?
This is the question that catches people out after delivery, and it is worth answering before you buy.
Infrared cabins typically draw 1.5–2.5kW and will usually run from a standard 13A socket. That makes them far simpler to install, and it is a large part of why they dominate the two-person outdoor market in the UK.
Traditional electric heaters commonly start around 3kW for a small cabin and rise from there. Anything from roughly 3kW upwards generally wants a dedicated hardwired circuit from the consumer unit rather than a plug.
Either way, you are running power to a garden building, which means armoured cable, an appropriate RCD, and Part P notifiable work. Budget for an electrician. Depending on the run and how much digging is involved this is frequently a four-figure job, and it catches people who budgeted only for the cabin.
Ask any supplier three questions before ordering: what is the heater's kW rating, does it need a dedicated circuit, and is the control panel rated for outdoor use.
Infrared or traditional: which suits a British garden?
| Infrared | Traditional | |
|---|---|---|
| Operating temperature | Roughly 45–60°C | Roughly 70–100°C |
| Warm-up time | 10–15 minutes | 30–45 minutes |
| Power draw | 1.5–2.5kW | 3kW upwards |
| Electrics | Usually 13A plug | Usually hardwired |
| Humidity | Dry | Adjustable — you control it with water on the stones |
| Running cost per session | Lower | Higher |
| The experience | Gentler, gradual | Intense, traditional, steam |
For a British garden, infrared wins on practicality — cheaper to install, cheaper to run, quicker to heat, and far more forgiving of the fact that you will want to use it for twenty minutes on a wet Tuesday in February rather than planning an afternoon around it.
Traditional wins on experience. If you have used saunas in Finland or at a good spa and that is what you are trying to recreate, infrared will not feel like the same thing. Be honest with yourself about which you are actually buying.
You can compare both formats across our sauna range and infrared saunas.
How much does a 2 person outdoor sauna cost to run?
Work it out yourself rather than trusting a marketing figure — the arithmetic is simple.
Energy used = kW rating × hours in use. Multiply by your unit rate.
For an infrared cabin at 2kW, a 45-minute session including warm-up uses roughly 1.5kWh. At a unit rate around 25p, that is approximately 38p per session — though note that infrared heaters modulate rather than drawing full power throughout, so real-world figures are often lower.
For a traditional 4.5kW heater with a 40-minute warm-up and a 30-minute session, you are nearer 5kWh, so roughly £1.25.
Substitute your own tariff. Both numbers are modest; the meaningful cost difference over a year is smaller than most people assume, and should not be the deciding factor between the two formats.
Where should you site it? Base, drainage and access
The base is not optional and is the second most common underestimate after electrics.
- It must be level and load-bearing. Concrete slab, paving slabs on a compacted sub-base, or a properly constructed timber deck. Not directly onto lawn or soil.
- Allow for drainage. Water must run away from the cabin, not pool beneath it.
- Ventilate underneath. Trapped moisture under a timber structure is what rots it. Most manufacturers specify bearers or a slight raise.
- Leave maintenance access. You will need to get to the back at some point. A sauna tight against a fence becomes a problem.
- Think about the walk. In January you will be doing it in a dressing gown. A lit, solid path from the back door changes how often it gets used more than any specification on the order form.
Also check the delivery route before ordering. Barrel saunas in particular arrive in large sections, and a narrow side return or a locked rear access has caused more than one cancelled delivery.
Should you add cold therapy?
Contrast — heat followed by cold — is the traditional pairing, and if you are already putting in a base and running power to the garden, it is far cheaper to plan for both now than to redo the groundwork later.
Practically it means leaving space adjacent to the sauna and thinking about where the water drains. Our cold therapy range covers the options, and even if you do not buy one immediately, leaving the space is free.
Seven questions to ask any supplier before you order
- What is the external footprint, and what clearance do you specify around it?
- What is the heater's kW rating, and does it need a dedicated circuit?
- Is the control panel rated for outdoor use, and to what IP rating?
- What timber is it, what thickness, and what treatment does it need annually?
- What does the warranty cover, and does it cover the heater separately from the cabin?
- Is delivery kerbside or to position, and what access width do you need?
- Is any assembly included, and if so, what exactly?
A supplier who answers all seven without hesitation is one worth buying from. If any answer is vague — particularly numbers four and five — that is worth noticing.
Frequently asked questions
Can a 2 person outdoor sauna run from a normal plug?
Most two-person infrared cabins can, drawing 1.5–2.5kW from a standard 13A socket. Traditional electric heaters at 3kW and above generally need a dedicated hardwired circuit. Either way, supplying power to a garden building is notifiable electrical work.
Do I need planning permission for a sauna in my garden?
Usually not, as garden saunas normally fall under permitted development for outbuildings, but height limits, boundary distances and land coverage rules all apply. Permitted development rights are restricted in conservation areas and on listed or some newer properties. Check with your local planning department.
How long does a 2 person sauna take to heat up?
Around 10–15 minutes for infrared, and 30–45 minutes for a traditional electric heater. In a cold British winter, expect the upper end of both ranges.
What base does an outdoor sauna need?
A level, load-bearing, well-drained base — concrete, slabs on a compacted sub-base, or a properly built deck. It should be ventilated underneath to stop moisture being trapped against the timber.
How much maintenance does an outdoor sauna need?
Typically an annual external treatment depending on the timber, periodic cleaning of the interior benches, and keeping the base and surrounds clear. Ask your supplier for the specific schedule for the timber they use, since it varies.
This guide covers the practical and installation aspects of choosing a garden sauna. It is not health advice. If you have a heart condition, low or high blood pressure, are pregnant, or take medication, speak to your GP before using a sauna.