This 16th century English barn now has a very modern Estonian sauna

Take a look at how Jack Ray tore out his spare toilet to build a sauna using design and technology from Estonia.

Adam Rang
13 min readFeb 13, 2022


How the sauna began as a spare toilet.

“Why don’t Brits have saunas in their homes?”

That’s the question that Jack Ray from Maidstone asked himself last year, prompting him to tear out a spare toilet in his family home to build his own DIY sauna — and now launch his own sauna building company, Raywood Saunas, to help more Brits enjoy saunas at home.

Jack is an avid fitness fan whose journey from casual sauna bather to authentic sauna builder began at his local gym.

Jack Ray, founder of Raywood Saunas in Kent

“I could feel the immense benefits of the sauna for recovery after an intense workout so I wanted to understand more about where saunas come from and why they work so well. However, the more I learnt, the more I realised that my gym sauna was a far reach from how saunas are properly enjoyed in Finnic cultures like Finland and Estonia where it is a neccesity, not a luxury.”

Jack’s gym sauna was a dark room with poor ventilation, signs saying “no water on the rocks”, low benches, nails and knots in the wood, and a metal box whirring away in the corner with a smattering of stones on top that were never able to heat the room to a decent temperature.

Jack’s home sauna

He thought, perhaps, he could do better — and a toilet room in his family home, long in need of a renovation, was the perfect place to find out.

This would be no amateur DIY task, however. Jack comes from something akin to royalty within the home building and renovation sector. His parents are award winning home builders and he works within the family business developing, building, and refurbishing homes across Britain.

Together, they made a plan for a very special sauna. It couldn’t just be a ‘hot box’. The sauna would be built in line with authentic sauna building principles and the focus had to be on the experience it offered. It should be big enough to offer a shared experience for family and friends, but fit into a challenging space not just physically but also asthetically within their 16th century listed barn.

The first task was to remove the existing walls and the toilet within it.

After that, they could properly visualise how big the new sauna should be. They decided to use a 2 square metre floor space with a ceiling height of 2.1 metres. They built the studwork out of 4x2 timber and installed the new ceiling height.

Just a quick note on terminology, most people around the world today think of a ‘sauna’ as the hot room, but in Estonian culture, that’s the leiliruum. Literally, the room for leil, which is Estonian for sauna steam. The sauna, meanwhile, tends to be the whole building and the whole experience within it, which includes a room for changing and cooling down. So in this article we refer to the ‘hot room’ specifically.

There was still a soil pipe in the corner of the room coming from an existing toilet one floor up but they wanted to ensure the hot room was totally free of clutter so they managed to move it just enough to keep it outside their construction.

As the room was already connected with water, however, they decided to keep that and install a tap within the hot room so that they have easy access to water, such as for washing, soaking a viht/vasta/vihta (those branches we beat ourselves with), and — of course — filling up the bucket to generate leil.

As a consequence, it was even more important to ensure the hot room has good drainage. Forgetting to install a drain is a classic mistake we see too often but this is important even without a tap. Fortunately, the nearby soil pipe provided a handy connection point for it to drain away.

Once the drain was down, the next task was to screed the flooring to bring the height up and properly embed the drain.

Then cabling had to be run through the hot room. While sticking to ancient and authentic sauna design principles, Jack was still able to accomodate all the neccersary mod cons that would need connecting, including an electric stove, lights, speakers, a mechanical fam, and the wall-mounted controller on the outer wall.

Jack had a very clear vision for how good lighting could provide the right atmosphere and aesthetic. The combination of lights would themselves be out of sight to maintain the clean and elegant appearance of the sauna but they would shine from above the backrest and below along each bench.

After the cabling was ready, it was time to insulate everything. The better the insulation, the better the efficiency of the stove. Jack used a minimum of 100mm of rockwool for the entire room but extra where there was more space behind the walls.

Next, they tiled the floor and fitted the aluminium foil membrane. This reflects the heat and also creates a protective barrier from any moisture build up.

Once the membrane was in place, it was time to baton the walls. This allows for air to flow freely behind the boards and further reduces the moisture build up and any thermal bridging, with the ultimate goal of creating the best sauna experience.

The final stage of the hot room construction was also the most rewarding for Jack. It was time to clad the inside and add the benches.

For the best sauna experience, it’s important to ensure a relatively even heat and steam around the body. This is traditionally done by building high benches with the feet elevated close to the top of the stove.

For both the walls and benches, Jack used aspen thermowood, which provides a traditional look and feel (and smell!) but is also specially treated to provide long lasting durability.

Jack sourced all the aspen thermowood from Thermory in Estonia, which was delivered by UK-based Finnmark.

Next, ventilation.

Ventilation is another one of the most often neglected features of a good sauna, especially in typical gym saunas. Too many people think the only objective is to keep heat inside the hot room, but if it has poor air flow then the sauna experience will be suffocating and leave you feeling sluggish. Instead, you want to comfortably enjoy the heat (usually while chatting with family and friends) and emerge refreshed. Jack ensured his sauna had good ventilation, which you can read more about in detail from HUUM’s blog here.

After that, the lights were wired and switched on for the first time. Here’s how Jack’s vision turned out:

The heart of the sauna

Finally, it was time to introduce the heart of the sauna, the stove, which we delivered from Estonia too. They chose a Hive stove by HUUM, which is a larger freestanding model, as well as a WiFi-connected UKU control system by HUUM, which includes a wall-mounted controller as well as use of the mobile app.

Jack used HUUM’s sauna calculator to work out that they needed a 9kW version. Fortunatley all stoves up to 9kW can be easily wired to single phase connections that are standard in UK homes (and, using a slightly different method, it’s also often possible with 10.5kW stoves depending on the power availability).

“We needed to ensure the stove was in keeping with our ethos and ideas to both look good but also provide a quality, authentic experience,” explains Jack.

“Compared to everything I had researched about authentic traditional saunas, looking around online I couldn’t help but think too many modern stoves are industrial, lacked design quality, and held very little stones. As we learnt, the more stones a stove held, the better the heat and leil, and the more enjoyable the experience. HUUM met these expectations, but are also pushing forwards with new smart technology, such as automatic safety features and allowing you to turn on and monitor your stove from your phone. It’s a stove based on traditional principles, but with a contemporary Nordic design and cutting edge technology. This matched everything that I wanted for our sauna.”

I should point out here that we’re never being too serious when we describe saunas abroad as ‘Estonian’ except to proudly show off that it was made with the help of Estonian design and technology. In reality, the sauna as most people know it is based on Finnic tradition — and both Finland and Estonia are Finnic nations — although quality saunas can also be found in a wide variety of international cultures whether based on ancient local roots or modern adaptions of the Finnic tradition. Even Britain has its own ancient sweat bathing traditions, which have been largely forgotton but are being revived by new enthusiasts like Jack. Is it really Estonian, Finnish, Finnic, or British? Well, the most important thing is actually that it meets the definition of a proper sauna!

“It was late at night when I sent a WhatsApp to Adam at Estonian Saunas asking him for some advice and asking him questions about the HUUM heaters. Much to my surprise, he responded straight away! Across the next 2 hours the information that Adam provided me with was invaluable and I knew that the HUUM stove met my idea of what a stove should be and I knew that Estonian Saunas were the company I wanted to buy from. Providing a high customer service from the start with continued support during and post build meant this was the best decision.

The last part was to make the external wall appear just as welcoming as inside the sauna, but also blend in with the rest of the barn. To do that, Jack cut up oak slithers and brick slips to create an outer wall that made the sauna look as if it had been there as long as the barn itself.

“Keeping with the tradition of the property whilst ensuring the sauna had that wow factor was really important to us,” said Jack. “The sauna is now complete and I am beyond happy with how it turned out.”

During the construction, Jack was eager to share updated photos of the construction, which generated huge interest among his friends and beyond who had plenty of questions — including how others could get their own home sauna.

“This really excited me,” said Jack. “Our interest in saunas began as a personal hobby but had quickly evolved into a passion that we could offer professionally. Incorporating sauna builds into our existing property development business was one thing, but we want to go beyond that and really specialise in authentic, quality home saunas. We think there’s a revolution taking place here and we want to help lead it.”

Raywood Saunas is born

And that’s how Raywood Saunas was born as a family run, small business building bespoke, traditional luxury home saunas with an ethos for quality experiences.

They’ve already secured long term partnerships with us and other suppliers to ensure they have the right materials for a range of bespoke, luxury sauna requirements.

“Estonian Saunas have amazingly listed us as a recommended sauna builder. It’s an honour to be considered linked with such a well-respected company.”

That was an easy decision for us, of course. This is one of the very best home saunas we’ve ever seen and Jack has both the skills and the passion to make a real difference to sauna culture in Britain. Our friends at Finnmark were also impressed.

“We love collaborating with our customers to help them on their sauna journey,” says Finnmark MD Jake Newport. “Jack was starting from scratch and had plenty of questions. We really love to talk sauna design and mechanics and Jack was all ears. We are so pleased to see how his project turned out!”

Raywood Saunas is based in Maidstone so mostly focuses on serving customers in and around Kent but is more than happy to hear from sauna enthusiasts there and beyond. Get in touch with Jack on and follow their work @RaywoodSaunas here on Facebook and here on Instagram.

Thanks for reading

This Estonian Saunas blog is run by Anni and Adam. We export Estonian sauna design, technology, & culture to the UK at We also have a EU shop at

Coincidentally, at the same time that Jack was building his sauna with deliveries from us and Finnmark, we were also in our own discussions with Finnmark about how we can work more closely together to help people like Jack and others. As a result, we are partnering to share their warehouse space, which will speed up deliveries, keep costs low (despite increasingly volatile import fees), and allow us to offer a wider range of Estonian sauna products. We’ve already added chimneys to our online shop and will soon be adding a full range of Thermory wood. As it happens, Anni is Estonia’s leading expert in carbon counting for environmental export declarations so is already working closely with Thermory to assist them with that. We’re really pleased to be able to expand and ultimately help more Brits enjoy more quality saunas, just like Jack is doing for himself and others.

You can follow our own sauna adventures on Instagram, Facebook, YouTube and Twitter. We also have a Facebook group for Sauna Builders & Explorers.

You can contact us at I can’t promise we will always reply quickly to Whatsapp messages but it’s true we do provide plenty of advice, ensure a smooth delivery, and are always ready to provide installation support.

Thank you for reading!



Adam Rang

Saunapreneur at Previously Chief Evangelist at Estonia’s e-Residency programme.