They are de rigueur in Scandinavian and Nordic countries, with as many as one for every household in Finland, where the old saying goes: “First build the sauna, then the house”, and it appears Britons are now following suit. Google UK searches for “home sauna” rose by 84% between January and March 2024 and the same period in 2020, according to the marketing company Semrush.

Hampson Architects – based in Brighton and working across the south-east of England – has seen a large uptick in demand. “On the larger houses (3,000 sq ft-plus) it’s increased from 30% wanting saunas to as high as 80-90% now,” says the managing director, Andy Parsons. “I think it will stay at that level now as there’s a market expectation to have them.”

While sales may not be quite as buoyant as they were during the height of the coronavirus pandemic, there’s still an upswing, with the manufacturer and retailer UK Saunas reporting turnover up 50% to 80% above pre-Covid figures.

“Covid was a big reason behind the popularity of saunas,” says Lewis Jenkinson, the technical officer at the British Sauna Society and the founder of the Cedar Sauna Company. “People made their homes as comfortable as possible using spare cash from the furlough schemes and the holidays they didn’t go on.”

Saunas aren’t just about relaxation – there are links to big health benefits, with studies reporting that regular use can lower blood pressure and reduce the risk of cardiovascular disease.

“There are so many benefits, from physical to mental,” says Dr Susanna Søberg, the founder of the Søberg Institute and the author of A Healthier and Happier Life Through Sauna and Cold Therapy. “Research has shown that using a sauna can mimic the effects of moderate intensity exercise, meaning that when you sit in a sauna of about 90C for more than 20 minutes on average, it can increase your heart rate and acts as exercise for the cardiovascular system.”

Plus, sweating can increase your metabolism and help burn calories, she adds. Regular sauna bathing is said to also alleviate stress, relax the muscles and increase mental wellbeing. However, Søberg warns that extreme hot and cold temperatures can be dangerous. “Be sure you don’t have a heart condition or irregular high or low blood pressure,” she says. If you are unsure, check with a doctor.

Choosing a sauna

The most traditional type is the Finnish sauna, which uses a wood-burning stove or electricity to heat the air, and fires up temperatures generally between 70C and 90C.

Alternatively, and increasingly popular, are infrared saunas, which use infrared light to heat the body directly, and typically have a lower heat range of between 45C and 60C. This type of sauna is not recognised by the International Sauna Association, which says to qualify the air must be heated.

Prices start from about £1,500 for a small infrared indoor sauna, complete with wooden hut and with enough space for one person, but can exceed more than £40,000 for a bespoke cabin, including your heating method of choice.

Indoor saunas

Jenkinson says many of those opting for an indoor sauna build extensions to create a designated room, or build it into an existing large bathroom, spare room or corner of a basement.

If you are considering a sauna in your home, Brian Clarke, a director at UK Saunas, says you need to investigate the electrical requirements of your sauna and consider if you can fit an extractor fan in the space. If it’s a traditional, Finnish, sauna, you will need drip-proof flooring, such as vinyl or tiles.

Generally, the most popular indoor saunas are infrared, Clarke says: “First, from a practical point of view, they run from a 13-amp (standard plug) socket – they don’t need waterproof flooring and maintenance is easier.”

But, he says, most of his own clients opt for outdoor saunas. “Most people’s houses don’t have the space to turn a room into a sauna,” he says.

Outside saunas

To set up a sauna outside, experts say that you need a concrete solid base, a dedicated power supply for a traditional sauna, and you will need to consider the distance from the house to ensure it can reach the power supply. “You need a cable fitted by an electrician from the fuse in the house to the sauna,” Clarke says.

As most saunas are under 2.5 metres high and are seen as portable buildings, planning permission isn’t generally needed, but it is worth checking in with your local council before you make a purchase.

If you want to keep your neighbours on side, it is worth speaking to them, too. And if you are weighing up a wood-burning stove, not only should you consider the environmental and health damage (make sure you are not in a smoke-controlled zone) but the impact on those around you. “These aren’t a good idea in residential areas, especially if using on a regular basis,” Clarke says, adding that some customers have converted to electric after neighbours complained to the council about the smoke.

Most people buy the full kit, including the building and heater, from a specialist company and either pay for someone to install it or, if they have the skills and temperament, they put it up themselves. However, you can build your own from scratch.

Jenkinson says that if you are thinking of going it alone or wish to bring in a builder, you will need a wooden structural timber to make the base, frame and roof for the cabin. “Some people put felt over the roof but you could have a rubber roof – it’s a lot more durable. External cladding can be cheap. You want a soft wood like spruce, cedar or aspen inside because hardwood such as oak gets too hot.” Labour costs could set you back from £8,000.

Jenkinson says a self-build sauna could cost between £5,000 and £10,000 in materials and equipment such as the insulation, cladding, bench wood, heater and rock. The British Sauna Society has a directory of installers and suppliers on its website.

If you have money to splurge, you could opt for a luxury handcrafted sauna. Those from Iglucraft, based in Estonia, start from just under €13,000 (£11,200), with additional transportation costs of about €2,000, plus VAT. That buys a steam sauna with enough room for four people and your choice of an electric or wood-fired stove. The sauna comes ready-built but you need to prepare foundations for it before it arrives.

Many of its customers personalise their saunas. “People change the length and play around with the layout in the room,” says the Iglucraft chief executive, Priit Kallas.

“Think about what you want – the durability, the craftsmanship and different types of timber.”

While temperatures soar, the costs of running a sauna are not as wild as you might think. “People think that because there’s a lot of powerful heating, they will eat a lot of electricity, but if designed properly, you only need to heat the room for an hour, then it switches itself on and off once it reaches the right temperature,” says Jenkinson, who estimates it would cost about £5 for the first hour, then half of that for every hour beyond that.

Budget options

Of course, an at-home sauna isn’t going to be within most people’s budget. Alternatives to building one at home are portable sauna tents, which come as wood-fired or infrared, and start from about £100, portable steam sauna pods – such as one by Vital+ which is effectively a steam-filled tent and costs from £249, and infrared sauna blankets, which also start at £100. Søberg is a fan of the latter. “I have one myself and think it’s pretty good as long as you’re sweating – that’s the main thing.” You could also look for a secondhand one to help reduce costs.

Fortunately, there are other places to sweat – albeit with others – with many gyms having saunas. They are also popping up in communities across the UK.

For example, Community Sauna Baths, a not-for-profit organisation with a selection of saunas and ice baths in Hackney, Stratford and Peckham in London, has sessions starting from £8.50, while membership is £20 a month, with 50% off sauna entry.

“We wanted to create an affordable sauna in London,” says the director, Charlie Duckworth. “It generates a stronger sense of community and social environment.”

With more than 400 members and 10,000 visitors every month, more are in the pipeline.

“It’s gone bananas. We believe they should be everywhere,” Duckworth says.

Ice baths

Ice baths are also having a moment, popularised in part by the Dutch motivational speaker Wim Hof. The form of cold water therapy is seen as bringing many health benefits, such as boosting the immune system and helping with muscle recovery.

From a practical point of view, UK Saunas’ Clarke says you will need access to a 13-amp socket, a cover to stop the rain pouring in, and somewhere to drain it. “Every couple of weeks you will need to change the water.”

For £85, you can buy Lumi’s portable Recovery Pod ice bath, with a lid and rain cover. You add cold water and it keeps it cool. For just under £4,500, Nuovo Luxury’s ice bath has a temperature control and a sturdy tub to sit in and can be used indoors or out.

Many enthusiasts use saunas and ice baths together. However, Søberg says: “Definitely take it slow. You don’t have to stay in the water more than a few minutes to feel the benefits.”

‘I feel a deep-rooted sense of joy and calm’

Given her mother is Finnish, Sabine Zetteler, 41, says it was only a matter of time before she achieved her lifelong dream of having her own sauna.

It happened earlier this year when she and her partner, Alex, installed one in their garden in Hackney, London, after saving £8,000 for the project.

“People think this is a wild luxury when actually we don’t have children and we don’t buy lots of things or go out for dinner or drink lots,” says Zetteler, who runs her own communications agency. “It was easy to be a little frugal as we knew the payback long term would be so wonderful.”

The sauna, from Polhus, cost £6,629 in total, including extras such as insulation, roofing shingle and shipping costs. The couple also paid £800 for an electrician for a full day, plus £650 for a gardener and foundation materials – the gardener helped build the foundation slab from broken bricks and went to buy the blocks the sauna floor beams rest on.

They saved money by putting it together themselves, with the help of some friends.

Zetteler says the sauna has already brought them a lot of enjoyment.

“It has made me feel a deep-rooted sense of joy and calm, and a connection to Finland, my mother’s homeland, that I really miss. It’s also very healthy, so in the darkest months it’s nice to have an injection of wellbeing.”