Outdoor saunas: How to turn your garden into a spa
Outdoor saunas are the hot, new wellness must-have. Here's how to buy one.
Saunas have been around in Scandinavia for thousands of years. In Britain, they are the hottest new wellness trend, with new saunas springing up across the country. The number of public saunas has risen from 45 in 2023 to over 600 as of last year – a 1,200% increase, while online searches for “outdoor sauna” have increased 73% year on year. Numerous studies attest to the health benefits of short, regular sauna sessions, which include improved cardiovascular health, pain relief and better mental wellbeing. So, why not install one in your garden?
Garden saunas come in three main varieties, based on their shape. Barrel saunas are the traditional choice for garden settings, blending in with the outdoors. Cube saunas are efficient in terms of space, adding a stylish touch to your outdoors with their clean lines. And at the premium end, you have cabin saunas, which offer greater flexibility in terms of layout, in addition to having more of an architectural feel.
How to install an outdoor sauna in your garden
As for the choice of wood, “ThermoWood is a reliable choice as it's treated to handle moisture and temperature changes, making it well-suited to the UK climate,” says Jake Newport, CEO of Durham-based sauna specialists Finnmark. He is also a member of the British Sauna Society and a host of The Sauna Twins podcast. ThermoWood is “also more stable over time, so [it is] less prone to warping,” he says.
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Spruce is another commonly used wood, especially in Nordic-style saunas. “It gives a clean, bright finish at a more accessible price point.”
Be sure to construct your sauna on a level, well-drained base and allow for airflow. “The UK weather is definitely a factor, particularly in terms of moisture and temperature changes over time,” says Newport. “That's where material choice and build quality really matter. Using properly treated timber, ensuring good insulation, and making sure the sauna is well-sealed and well-ventilated all play a role in its long-term performance. But if those elements are right, an outdoor sauna will handle UK conditions without issue.
“Naturally, simpler designs are generally quicker to install, while more considered builds take more time and planning, particularly if groundwork or electrical connections are involved.”
Types of garden saunas
1. Barrel saunas
The distinctive cylindrical shape of barrel saunas has made them a popular choice in British gardens. But it's not just because they look good. The curved walls promote efficient heat circulation, which allows for the hot air to flow naturally through the space rather than becoming trapped in the ceiling as can happen with some traditional square saunas.
Rounded sides also help the sauna to heat up more quickly and to maintain its temperature more efficiently. A barrel sauna can reach its optimal temperature in as little as 30 minutes, depending on how you choose to heat it and the conditions outside.
Wood-fired heating is the traditional choice and can be cheaper to run than electric, depending on the availability of wood and local regulations permitting. However, electric tends to be cleaner and more practical.
The ThermoWood Barrel Sauna – Regular with Changing Room accommodates two to four people.
Price: £7,401.99 without a heater and £8,859.99 with a Huum Drop 9kW electric heater.
Barrel and patio saunas typically cost from £4,000 to £15,000, while more complex modular designs range from around £12,000 to £30,000. The cost of a bespoke build starts at £40,000 and “can rise significantly depending on the specification”. Planning permission won't be required for most outdoor saunas, so long as they meet size and placement rules. But it's worth checking with your local authority, especially if you live in a listed property or in a conservation area.
Don't forget to leave yourself a space outside to cool down after your sauna session, says Newport. That helps to “make the sauna a regular habit rather than something you use occasionally”.
For further information on saunas, prices and availability, visit finnmarksauna.com.
2. Cube saunas
Create a dedicated wellness space in your garden by installing a cube sauna, particularly if your garden is small and you need to make the most of the space available. The sides are made from ThermoWood, which has been heated to 200°C in a controlled environment that alters the wood's cellular structure and makes it resistant to decay, moisture and warping. No chemicals are used, and the wood naturally takes on a darker, richer appearance.
It also means they can withstand British winters with no problems. During the colder weather, you can easily move from the heat to the bracing outdoors to make the most of the health benefits. Cube saunas are heated with an electric heater, and because of their compact size, they are ideal for couples and first-time buyers. For privacy, consider installing near screening plants or fencing.
The Thermo Wood Cube Outdoor Sauna – Mini costs £4,993.99, without a heater and £5,522.98 with a Narvi NM Domestic 6kW electric heater.
3. Sauna cabin
For those with larger gardens and bigger budgets, sauna cabins offer the pinnacle of garden luxury, combining all the health benefits of a traditional sauna session with contemporary Scandi design. The Finnmark Eden Outdoor Sauna accommodates five or six people. It has a roof overhang with space to hang your towels and a stylish glass door that extends to a side window, which allows for extra light to enter. The walls are made from “thermo pine” and a heat-treated knot-free wood for the interiors. Inside, the L-shaped bench made from “thermo aspen/alder” makes this an ideal place to unwind and socialise in the comfort of your own garden.
Price: £19,995.00 without a heater, £23,020.50 with a Narvi Velvet 10.5kW electric heater and £22,980.00 with a Huum Hive Flow wood-burning heater.
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