There's something about a home sauna that conjures up an era of prawn cocktails, swirly carpets and suburban swingers. Quite why it is that these innocent Nordic heated cabins should inspire such Seventies connotations is a mystery. Of course, there are "those" sorts of saunas – open late in backstreets – but surely we've all been to enough gyms and spas for a post-workout muscle relax, in a no-hint-of-slap-and-tickle environment, to overcome the giggly reactions?
" I think in Britain they've always had a slightly naughty image – a bit of a 'nudge, nudge, wink, wink' association," accedes Brian Grey, marketing manager for Ideal Standard, which launched "Tris", a domestic wood-clad bathroom cabin combining a shower, steam room and sauna, three years ago. Perhaps it is the sauna's traditional communal element – and the fact that it's best enjoyed naked – that prompts the saucy image.
"Europeans have always been very open to having saunas – and to sharing saunas," Grey says, "whereas here, it's almost had a 'Carry On' thing about it. But as Britain has become more sophisticated, people have become much more open to it."
So it would seem: since its launch, sales of the unit – which costs from around £8,700 (including installation and training on how to use it) – have doubled. The three-in-one home spa is big enough for two, yet doesn't take up much more floor space than the average bathtub, measuring just 170cm x 110cm, and is designed to fit into domestic bathrooms or anywhere there is an appropriate water and electricity supply. In its sauna capacity, it reaches temperatures of 30C, which matches the professional versions.
And Tris is far from the only indication that we're falling in love with the idea of a home sauna in the UK. Dozens of British companies are starting to sell their own variations – Argos sells a range, starting at just over £1,000, while B&Q has sauna cabins for the garden from around £1,600. Infrared saunas – which create a different sort of heat from the classic hot-stone types, and do not require drainage or a water supply – start from as little as £600, and need nothing more than a plug socket and the empty corner of a room.
The ancient Greeks probably invented the whole idea, with their hot-air baths or laconicae, while Islamic hammams, Turkish baths and sweat lodges have all provided variations. The sauna as we know it, however, is widely attributed to the Finns, who, as long as 1,000 years ago, according to some sources, developed it as a way to keep warm during harsh winters. Then, it was little more than a primitive pit in the ground, heated by stones warmed on the fire: to increase the temperature, water would be thrown over the stones, which created steam – and often provoked the subsequent removal of clothes.
The sauna has evolved and proliferated, becoming a staple in hotels, gyms and spas. And now, thanks to increasingly sophisticated technology, it is also fast becoming the bathroom accessory du jour. "There's been a general trend over the last few years for creating more of a spa-like feel in the home," Ruth Bell, deputy editor of Kitchens Bedrooms & Bathrooms magazine, says. "The desire for relaxation and to get away from the outside world fits in with the need to create a haven in the home. And in particular, a sauna/steam room is a place where you can just be on your own and really get away from it all. And with a one-off outlay rather than an annual membership, it makes financial sense too."
David Taylor, from Leeds, sales director of a hotel chain, couldn't agree more: "I've got a fairly stressful job," he says. "I'm director of a company that owns 18 spas so I'm familiar with saunas and the benefits that they bring. But I'd never thought about having one at home, but then a colleague told me about the recent advances in technology, which sparked me to think about a sauna as a domestic product. And after a bit of Googling, I found Divapor.com."
Taylor spent about £2,000 on his two-person infrared sauna, and set it up in his home office. "My 11-year-old son and I assembled it in less than an hour, and then you just plug it in and you're away." So how do the family enjoy it? "I don't let them use it. They know it's my little sanctuary, where I go two or three times a week to sit with a book or to listen to music – it's got a CD player. I read the papers every Sunday morning in there. It's just a great way to chill out. And during the winter months, they're obviously very warming and great for lifting the mood and spirit."
Taylor chose an infrared sauna because it seemed more convenient. He also prefers the type of heat it generates, which relies on carbon panels, rather than raising the air temperature excessively, meaning a lower heat does the job. "You'd think it would be quite power-hungry but it's not," he says. "It's made virtually no impact on my electricity bill."
Chris Barnwell from Surrey, the director of a technology consultancy, hit the higher end of the market with his traditional hot-stone sauna, custom-made by Dröm UK for around £6,500. He and his wife created a luxury spa at their home. "I'd tried the infrared ones and heat doesn't seem to be as penetrating," he says. "I wanted a more intense heat, and I like to run it really hot."
The design is beautiful, he says, and built from very high-quality white pine ("if there are knots in the wood they can become too hot to lean against or sit on, so it's worth spending the money," he explains). The couple use it twice a week or more. "It's great after using the gym, or if it's a cold evening it's a nice place to relax."
Style-wise, if you want to go beyond the basic, there are options for every taste: the Swiss company Badebotti makes slick, wood- burning human-sized barrels that would look good in an urban garden, while Italian Effegibi and Swiss Küng Sauna offer minimalism and clean lines with their ultra-modern glass boxes. You can even get a "smart" sauna: the mPulse series by Sunlighten measures how many calories you've burnt, along with tickling your senses with sound and vibration therapy and colour-therapy lighting.
Not all of these designs are available in this country, but we're beginning to catch up. A year ago, Duravit launched the Inipi here (from £15,709) – a lavish glass-fronted model with all sorts of futuristic features: you can, for example, set different "scenarios", such as "prairie", which gives you a soundtrack of horses and crackling fires. Whether the sound effects do it for you or not, it really is a thing of beauty.
"We wanted it to look like furniture," Jörn Ikels, a senior manager at Duravit, explains. "We thought that would make it easier to adapt to the atmosphere you have already in the home – in the bathroom or even the living room. We didn't want it to be something people stuck down in the cellar, which is commonly where saunas live in German households."
Are we really ready for home saunas? "People are going more and more to spas," Ikels says. "They come home and they want to take the experiences they've had with them. Especially saunas, because the real ones you use while naked, and nakedness in public is something that a lot of people – not only British, but also Middle Eastern and Italian people – don't like. So a sauna in your own home? It is the perfect solution."