Sauna as an architectural object

The traditional sauna originated more than 2000 years ago in the north of Europe. They were simple log structures with wood stoves, thick walls and minimalist decoration. They were stoked in the “black” way, which means that to save fuel and maximize the temperature inside, stoves without a chimney were installed, filling the space with heat and smoke. It takes about half a day to warm up a room in this way: the process cannot be rushed and the preparation itself becomes a meditative practice. The walls and ceiling are darkened in the process. This sauna was called “savusauna” (in Finnish savu “smoke”). The modern name is most likely derived from the word “savuna”, i.e. “in smoke”.

Modern baths are mostly “white” and have many regional differences. In the Finnish variant, the heat is dry and the steam temperature is 80-100°C. In the traditional Swedish sauna – called bastu – the humidity can be slightly higher. The Russian sauna (banya) is considered more “wet” – the humidity is 40-70%, while the temperature is the same as in a sauna. The Turkish version – hamam – is considered the mildest; the temperature is 40-50°C, humidity is close to 100%. 

No matter how different they may be, all traditional bathing cultures have components that unite them: the purification of the body and mind through processes involving water and heat, and social interaction during the bathing ritual. Designing a good sauna means taking both into account.

Sauna’s architecture 

The most famous architect who designed saunas was the Finn Alvar Aalto. He built saunas almost everywhere in his residential buildings, and in his own summer residence, the Experimental House on the island of Muuratsalo, he built a black sauna with a grass roof (a black sauna has no chimney). On the banks of the Eurajoki River is his public sauna, Jokisauna, for workers at the nearby Kauttua steel mill. The log and brick building originally also had a grass roof. 

Nowadays, the sauna is no longer an addition to a house or a community center, but an object in its own right. For architects, working on such a building opens up a wide range of imagination: the focus of such projects on people’s well-being, combined with new materials and constructions, make the sauna a prominent small architectural form. Tempered panoramic glass, concrete and steel now complement the classic wooden log cabin, allowing the project to be integrated into the urban infrastructure and nature with equal success. 

Materials

Wood is the best material for saunas; in most cases, local species with a natural texture are used for construction. Today, however, architects are increasingly using alternatives such as concrete or granite. 

Concrete saunas include Kulttuurisauna in Helsinki. It is a freestanding complex on the shore of the bay in the central Merihaka district. Opened in 2013, the building was designed by designer Nene Tsuboi and architect Tuomas Toivonen, who also own the sauna. The white facade hides a minimalist but cozy Japanese-style interior made of raw materials: plywood beams, heated cast concrete with traces of formwork. At the back of the building is a quiet, enclosed courtyard with sea views and a slope down to the water. 

If Kulttuurisauna is designed for several dozen people, the name of the One Man Sauna project speaks for itself. It is a small structure – a tower 7.5 meters high on the site of an abandoned factory in the German city of Bochum. The project was built from stacked prefabricated concrete parts that were originally used to build mines. The sauna has three levels: a small pool on the first, a steam room on the second, and a relaxation room on the third. The floors are connected by a vertical staircase, like those found in water towers and other industrial facilities. The authors of the building are the Borderlands Research Laboratory, which studies the border and transit spaces of Bochum as part of the urban system of the Ruhr region. 

In 2020, the Berlin-based architecture group Raumlabor presented an equally radical project in Gothenburg. The architects created a brutal sauna with corrugated steel facades to liven up the Frihamnen harbor area, which is gradually losing its industrial character and turning into a trendy urban space. Aside from the unusual geometry and cladding, it’s a fairly traditional sauna inside, where people steam surrounded by larch wood walls. 

Also in 2020, the art and architecture studio Studio Rain installed a temporary sauna in the suburbs of Melbourne, Australia. The main features of this project are quick assembly, autonomy and mobility: it can be easily assembled and disassembled without the use of construction equipment. Polycarbonate proved to be the most suitable cladding material. As Studio Rain co-founder Rachel Mackay explains, the fiberglass facades and roofing allow the environment to penetrate the interior just enough to keep the people inside in touch with nature while still providing privacy.  

Constructions

Another way to rethink the sauna is to look for alternatives to traditional design and construction techniques. 

Located on the shores of Lake Ontario, Canada, the Grotto Sauna has an understated exterior, with only the shimmering windows facing the lake. This image was created by the architectural firm PARTISANS in response to the client’s desire to create a building that would not conflict with the natural environment. The interiors are much more striking: in the steam room, they managed to create an incredible grotto-like space without a single right angle. The architects used 3D scanning technology and worked closely with a local carpenter. 

Open AD architects chose the opposite strategy – using ancient but atypical technologies – when designing a sauna at the Ziedlejas Wellness Resort in Sigulda, Latvia. The name of the project, Wool Sauna, was chosen because the sauna is housed in a yurt-like structure hidden behind a black wooden facade. The walls are upholstered with wool that, when heated, releases lanolin, which is believed to have healing properties. A palette of materials such as wood, concrete, metal, and natural fabrics connects the sauna to other parts of Ziedlejas – the lodge villas, as well as the Glass Sauna and Smoke Sauna buildings.

Another unusual interpretation in 2017 was offered by the artistic duo Bigert & Bergström and the Swedish bureau White Arkitekter. In Kiruna, Sweden’s northernmost city, they created an egg-shaped sauna made of gilded metal. The project came about after locals expressed fears of population exodus and loss of community spirit. “Sunny Egg,” as its creators call it, is a ‘social sculpture’ that serves as a colorful landmark and meeting place. It consists of 69 individual pieces of gold-plated stainless steel sheets that together form a multi-faceted oval.

While every detail of the sauna in Kiruna is designed to be as visible as possible, Apfelsauna by Italian studio NOA is camouflaged in the landscape. It is nestled between the boutique Apfelhotel and the apple orchards of an estate in northern Italy. The base of the building is formed by two horseshoe-shaped concrete slabs dug into the hill, with the entrance to the sauna on one side and the steam room with a panoramic window overlooking the apple trees on the other.  

Structure

The floating sauna is one of the most popular saunas in Scandinavia. Oslo has 15 public saunas of this type, commissioned by the Oslo Sauna Association in the hope of “making sauna accessible to the people”. One of the newest, located in the center of the city, will open in 2024. This project by Estudio Herreros is a pre-assembled cog-shaped structure installed on a floating platform. On the roof of the sauna is an amphitheater that acts as a kind of public space and viewing platform overlooking the Munch Museum and the Norwegian Opera. 

An outdoor amphitheater is also part of The Bands project at the Oslo School of Architecture and Design: in 2015, students designed and built a coastal sauna consisting of two wooden buildings. From these, three stepped picnic terraces extend over the rocky landscape. They overlook the waterfront of a former fishing village on the Lofoten Islands. 

BarlisWedlick’s interpretation of the sauna takes the form of a three-level tower with an observation deck in New York’s Hudson River Valley. The upper platforms are made of Alaskan yellow cedar. The frame is supported by Y-beams. The intermediate floor is sheathed in a mesh membrane that allows air to pass through but keeps out insects. The upper floor is covered by a sloping roof. 

Community saunas pay attention to both places to relax and places to work. In a sauna complex in Tampere, Finland, Puisto Studio has embraced the long-neglected idea of a “common living room” for residents of the surrounding neighborhood: a bistro with local delicacies and a co-working space. In the late 19th century, such saunas were very popular in Finnish cities: there was too little space in apartment buildings to accommodate a large group, and in the so-called kortellisauna (kortellisauna means “local sauna” in Finnish) people came not only to bathe, but also to socialize and exchange ideas.

To create a cozy interior space and isolation from the city noise, the exterior windows are made of translucent glass with a soft, milky hue reminiscent of sauna steam. “The resulting ambiance is a calm, peaceful one that creates a resounding appetite for sauna from the moment one steps inside,” says the studio.