{"id":36761,"date":"2026-09-26T06:34:40","date_gmt":"2026-09-26T04:34:40","guid":{"rendered":"https:\/\/istaspirtslietas.lv\/?p=36761"},"modified":"2026-09-26T06:34:40","modified_gmt":"2026-09-26T04:34:40","slug":"sauna-of-the-future-taiyo-tsubomi","status":"publish","type":"post","link":"https:\/\/istaspirtslietas.lv\/en\/sauna-of-the-future-taiyo-tsubomi\/","title":{"rendered":"Sauna of the Future \u2013 can wooden walls be replaced by air and membrane?"},"content":{"rendered":"

Sauna of the Future may look completely different from the traditional wooden sauna. TAIYO TSUBOMI, created for Expo 2025 Osaka, demonstrated that heat and humidity can be retained inside a structure whose walls are made not from solid timber, but from a thin ETFE membrane and air. Ten inflatable elements, each approximately eight metres high, formed a translucent, light-filled sauna space, while in September 2026 the architectural press once again highlighted the project as a possible glimpse into the future of sauna design.<\/strong><\/p>\n

TAIYO TSUBOMI was created for Expo 2025 Osaka-Kansai in Japan as an experimental sauna combining wellness, architecture and material technology in a single project. The design was developed by KOMPAS, while Taiyo Kogyo was involved in the engineering, manufacturing and installation of the membrane structure.<\/p>\n

From the outside, the building resembles a huge white flower bud or a futuristic pavilion more than a conventional sauna. Behind its unusual appearance, however, lies a very specific technical experiment \u2013 whether a lightweight pneumatic membrane can create a fully functional hot and humid sauna environment.<\/p>\n

Sauna of the Future is built with air<\/h2>\n

The principal construction material used in TAIYO TSUBOMI is ETFE, or ethylene tetrafluoroethylene film. It is a lightweight and durable fluoropolymer that is also used in architecture as an alternative to glass.<\/p>\n

In the sauna structure, the membrane forms air-filled cushions. The sauna section consists of ten such elements, each approximately eight metres high and two metres wide.<\/p>\n

They are positioned closely together to retain heat and humidity inside the space. The insulating function is therefore provided not only by the membrane itself, but also by the air enclosed within it.<\/p>\n

The result is a structure that works very differently from a conventional solid sauna wall.<\/p>\n

A membrane only 0.25 millimetres thick<\/h2>\n

One of the most surprising details is the thickness of the material. According to Taiyo Kogyo, the ETFE film is only 0.25 millimetres thick<\/strong>.<\/p>\n

Despite this, the material is durable, lightweight and suitable for long-term use. ETFE is also valued in architecture for its resistance to weather conditions and its ability to create extremely lightweight structures.<\/p>\n

In TAIYO TSUBOMI, a minimal aluminium frame, membrane and air replace a much heavier conventional wall system.<\/p>\n

This is where the project becomes interesting not only to sauna enthusiasts, but also to architects and structural engineers.<\/p>\n

Up to 90% of natural light passes through the walls<\/h2>\n

A traditional sauna is usually a relatively dark space. Timber, small windows and subdued lighting create an enclosed environment in which the visitor is, to some extent, separated from the outside world.<\/p>\n

TAIYO TSUBOMI does almost the opposite.<\/p>\n

The ETFE membrane allows approximately 90% of light<\/strong> to pass through. Daylight diffuses through the white walls, making the interior bright while still maintaining a necessary sense of privacy.<\/p>\n

As daylight changes, so does the atmosphere inside the sauna. On a sunny day, the structure feels bright and lightweight, while in the evening artificial lighting can transform the membrane into an illuminated architectural object.<\/p>\n

The sauna and cooling area use the same principle<\/h2>\n

One of the project’s most interesting features is that the architects used the same material to solve two completely opposite problems.<\/p>\n

In the sauna area, ten ETFE cushions are positioned close together to retain heat and humidity.<\/p>\n

In the water and cooling zone, another ten similarly sized elements are arranged much more openly. Air can circulate between the membranes, creating natural cross-ventilation.<\/p>\n

The same structural system therefore helps preserve heat in one part of the complex while encouraging cooling in another.<\/p>\n

The structure resembles a flower bud<\/h2>\n

The name TAIYO TSUBOMI can be translated as \u201cSun Bud\u201d. Its architectural form was not chosen by accident.<\/p>\n

Each pneumatic element has a tetrahedron-like geometry. This shape allows a large volume of air to be enclosed using a relatively small amount of material and structural components.<\/p>\n

Together, the elements create an upward-pointing form resembling the bud of a flower.<\/p>\n

The structure is therefore more than a technical solution. Its form, material and name are all part of the same architectural concept.<\/p>\n

8.4 metres \u2013 a world record for a membrane sauna<\/h2>\n

The experimental nature of TAIYO TSUBOMI has also been recognised beyond the architectural world.<\/p>\n

In October 2025, the sauna was officially recognised by Guinness World Records as the world’s tallest membrane-structure sauna<\/strong>.<\/p>\n

Its certified height is 8.4 metres<\/strong>.<\/p>\n

This does not mean that future saunas need to become increasingly tall. Far more interesting is the fact that a sauna building has become a testing ground for architectural structures and materials that have traditionally had almost no connection with sauna design.<\/p>\n

Does a plastic membrane belong in a sauna?<\/h2>\n

From the perspective of traditional sauna culture, the question is entirely reasonable. For centuries, sauna interiors have primarily been built from wood, and the feeling of natural timber has become an integral part of the sauna experience.<\/p>\n

TAIYO TSUBOMI suggests that the essence of a sauna does not necessarily depend on the material used for its walls.<\/p>\n

What matters more is the ability to create the required microclimate \u2013 retaining heat, controlling humidity and providing an environment in which people can experience sauna properly.<\/p>\n

This does not mean that ETFE will replace wood in traditional saunas. Instead, the project demonstrates that public and experimental sauna architecture can make use of a much broader range of materials.<\/p>\n

The sauna was designed as a complete experience<\/h2>\n

TAIYO TSUBOMI was not simply an unusual room containing a heater.<\/p>\n

During Expo 2025, visitors took part in a structured sauna experience combining heat with cooling, rest, light, sound and the surrounding environment.<\/p>\n

The complex included the sauna itself, a water zone and relaxation areas. The architectural concept encouraged visitors to move through different states rather than simply entering a hot room and then stepping outside.<\/p>\n

The form of the building therefore became part of the sauna ritual itself.<\/p>\n

Lightweight construction opens new possibilities<\/h2>\n

Perhaps the most interesting characteristic of ETFE is not its futuristic appearance, but its extremely low weight.<\/p>\n

A conventional sauna building requires walls, thermal insulation, interior finishes and appropriate load-bearing structures. A pneumatic membrane system allows some of this mass to be replaced by air.<\/p>\n

In theory, this opens possibilities for lighter temporary or seasonal saunas, larger public sauna spaces and structures in locations where constructing a conventional heavy building would be more difficult.<\/p>\n

Of course, an Expo pavilion is an experimental project. It does not automatically mean that membrane saunas will soon appear around the world.<\/p>\n

The technological principle, however, has already been demonstrated in practice.<\/p>\n

After the Expo, the sauna is attracting architectural attention again<\/h2>\n

Expo 2025 Osaka ended in autumn 2025, but the story of TAIYO TSUBOMI did not end with it.<\/p>\n

In September 2026, the professional publication Fabric Architecture Magazine<\/em> highlighted the project again, asking a very direct question \u2013 could this be the future of saunas?<\/p>\n

The interest is not simply about its unusual appearance. For the architecture industry, the important combination is a pneumatic structure, an insulating layer of air, high light transmission and the ability to create dramatically different microclimates using an extremely lightweight material.<\/p>\n

That is why the project continues to attract attention more than a year after its opening.<\/p>\n

Will the sauna of the future still be made of wood?<\/h2>\n

Most likely, yes. Wood is not going to disappear from sauna culture. It has highly suitable physical properties, a centuries-old cultural connection with sauna and a sensory quality that an artificial material cannot simply replace.<\/p>\n

But TAIYO TSUBOMI shows that the question can be approached differently.<\/p>\n

Perhaps the sauna of the future will not have one specific architectural form. A traditional log sauna, a modern timber sauna, a floating sauna, an urban public sauna and a lightweight membrane structure can all exist alongside one another.<\/p>\n

The important question is whether the space can create a good sauna microclimate and a meaningful experience for the people using it.<\/p>\n

Sauna of the Future TAIYO TSUBOMI demonstrates how far it is possible to move away from the conventional image of a sauna building without losing the fundamental ideas of heat, humidity, cooling and rest. Its walls are only a quarter of a millimetre thick, much of the structure consists of air, and natural light flows freely through the space. Perhaps the future question will no longer be \u201cwhat should sauna walls be made of?\u201d, but rather \u201cdo sauna walls need to be built in the way we have always built them?\u201d<\/strong><\/p>\n

Sources<\/h3>\n

Fabric Architecture Magazine \u2013 The future of saunas?<\/p>\n

Taiyo Kogyo Corporation \u2013 Expo Sauna \u201cSun Buds\u201d Update.<\/p>\n

Taiyo Kogyo Corporation \u2013 Expo Sauna \u201cSun Buds\u201d Recognized by Guinness World Records.<\/p>\n

Taiyo Kogyo Corporation \u2013 EXPO \u00d7 TAIYO.<\/p>\n","protected":false},"excerpt":{"rendered":"

Sauna of the Future may look completely different from the traditional wooden sauna. TAIYO TSUBOMI, created for Expo 2025 Osaka,<\/p>\n","protected":false},"author":4,"featured_media":36753,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3118,3117,3123],"tags":[],"class_list":["post-36761","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-architecture","category-sauna-news","category-technology"],"acf":[],"_links":{"self":[{"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/posts\/36761","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/comments?post=36761"}],"version-history":[{"count":2,"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/posts\/36761\/revisions"}],"predecessor-version":[{"id":36763,"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/posts\/36761\/revisions\/36763"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/media\/36753"}],"wp:attachment":[{"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/media?parent=36761"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/categories?post=36761"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/istaspirtslietas.lv\/en\/wp-json\/wp\/v2\/tags?post=36761"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}