Students build pop-up sauna: ‘No better cure for a long cold winter’

“Aaaaaahhh!!” Amid the laughter and conversation, a loud splash and a scream sometimes fills the air on X’s grounds. A sweaty Italian student in swimming trunks closes his eyes and pulls a rope to have a bucket of ice cold water splash all over him. He stays calm in the midst of all the cheering around him. “I am bursting with energy,” he laughs.

Before he took the cold shower, he was one of the first visitors to the Sweat pop-up sauna. The sauna has been on the grounds of X since last week Thursday, and it will stay there for three weeks. For just EUR 2.50 per time, students and staff members can immerse themselves in temperatures of about 80 degrees Celsius. There is much interest and most time slots so far were sold out.

Passion project

The sauna is the outcome of one year of hard work by five students at Architecture and the Built Environment: Jacob, Markus, Luna, Maxi and Tom. They were looking for a passion project to work on in which they could use their hands alongside their theoretical master’s. They got the idea of a sauna in February 2024, Tom explained to Delta. He, a sauna enthusiast himself, goes to a sauna once a fortnight. “There is no better cure to get through a long cold winter.”

Their original plan – a permanent sauna where visitors could relax in the nude – had to be adapted for privacy and social safety reasons

But there are not that many affordable saunas in and around Delft, and wellness spas are pricey, sighs the German master’s student. “You can easily spend EUR 30.” The team did not consider this okay. Nor very inclusive. So their sauna only costs EUR 2.50 a time. That price entitles you to half an hour sitting in the sauna, although the team recommends around 10 minutes. People from outside who are not TU Delft students or staff members pay EUR 7.50.

The team got the green light to build their dream with the support of the Faculty of Architecture and the Built Environment, experts from The Green Village, suppliers, and the X sports and cultural centre. Their original plan – a permanent sauna where visitors could relax in the nude – had to be adapted for privacy and social safety reasons. A temporary and dressed version was the solution.

Circular

The eight person sauna is not only a pop-up, it is also circular. The team got help from various organisations to bring this about. PERI – a supplier of building materials – supplied the ‘form work’ which is recognisable as the yellow columns and beams. In construction these are used to keep freshly poured concrete in place. They usually go back to the supplier after use. Now the sauna team may use it for free in return for promoting the company.

They may also use the plywood boards, from which the sauna seats and the balcony were made, free. These were made from discarded wood that was stored in a warehouse waiting for a use. Tom does not dare predict what will happen to them after the sauna is dismantled, but they might be of use in the workshop of Architecture and the Built Environment.

The large plates of polycarbonate (very strong, thick and transparent plastic) which were used for the walls of the sauna and the furniture on the balcony, were given free. They are secondhand and the pop-up sauna can reuse them. While it may be a weird idea having a sauna made of plastic, the plates are highly suitable. Tom explains why. “They are made of two layers and are vacuum sealed on the inside so they are excellent insulation.”

Another gift was the electric heating element that heats the area up to about 80 degrees. Tom hopes that it will eventually be used in a permanent sauna. The electricity comes from X, which considered burning wood too dangerous.

Exchange

To cover the costs that the team did incur, the five of them put together three grants from X, Stud and the Faculty of Architecture and the Built Environment. Of the ticket sales, half will go to X and the other half to the team. Added up, it covers the costs.

Two team members returned from a study trip to Finland, not only for the sauna project, with a huge amount of information. They also went to the Kuuma sauna, a temporary sauna on Scheveningen beach that is there for a few months a year, to experience for themselves how a group session in a pop-up sauna works.

The opening on Thursday evening was the climax of a very special year

Despite the amount of time – ranging from one day a week to full-time during building – they put into the project, all five master students are on track for their graduation projects. It really is a dream team, said Noortje Dik, X’s Project Manager, in her speech at the opening. She oversaw the sauna team during their busy year. “The team collaborates amazingly well. They cared so much for this project, it’s almost like their baby.”

Delta was at the opening of the Sweat pop-up sauna. (Video: Delta)

Climax

The opening on Thursday evening was the climax of a very special year. At least 50 people stood on the balcony of the pop-up building chatting with a cup of tea or a brownie baked by Luna’s mother. Some were already in their swimsuits and were waiting patiently until a place came free in the sauna. They disappeared into the sauna one by one only to reappear 10 minutes later completely covered in sweat for the cold shower.

Should there be a permanent sauna? Definitely, says one student who just came out of the shower. “It would be lovely if this were on campus permanently, not in summer, but in the long, cold winter.”

So will the sauna team get building again? Tom laughs. “We first need to graduate. But if a festival or event approaches us for a pop-up sauna, we will certainly think about it.”