Ondsauna Sauna by Taro Shimokawa is a highly esteemed winner of the very prestigious 2025 A' Design Award an Bronze in Architektur, Gebai an Strukturdesign Competition Category.

BronzeArchitektur· 2025

Ondsauna Sauna

by Taro Shimokawa

Client: Ondpark

A' Design Award an Bronze Winner in Architektur Category

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Verified Award Winner

Verify Award Status for #165443

View at A' Design Award Press Release Award Badge

Colors

The Design

About Ondsauna Sauna

Ondsauna ass e Saunagebai, dat an engem Bësch integréiert ass. Vertikal Aussewänn sinn ronderëm de Saunaraum gruppéiert, wat d'no uewe wuessend Beem widderhëlt. E spiralfërmegen Wee féiert op en Entspannungsraum um Daach. Den Agank läit 250 Millimeter iwwer dem Buedem, d'Plattform fir d'Kaltwaasserbad op 1000 Millimeter an d'Daach op 3250 Millimeter, sou datt d'Beweegung vun der Sauna iwwer d'Kaltwaasserbad bis un déi fräi Loft vertikal verleeft. En onregelméissege polygonale Grondriss a stumpwénkeleg Bänke leede d'Bléckrichtungen a loossen d'Besucher hire Grad vun Interaktioun selwer wielen.

The Recognition

About the A' Design Award an Bronze

Ondsauna Sauna ass e Gewënner vum A' Design Award an Bronze, enger héich prestigiéiser Unerkennung, déi un erausragend Designe vergi gëtt, déi sech duerch Kreativitéit, Erfindungsgab a Schlauheet ausgezeechnen. Bronze-Gewënner si voll Fäegkeet a opfälleg kreativ Wierker, déi déi grouss Erfahrung, d'Fantasie an d'Ressourceréichtum vun hire Designer bestätegen. Et gëtt erwaart, datt Ondsauna Sauna e héich geschätzt, bewonnert a beléifte Géigestand ass, bemierkenswäert professionell an innovativ. Dëst mam Bronze ausgezeechent Design integréiert déi beschte Praktike vun der Konscht, der Wëssenschaft, vum Design an der Technologie an zeechent sech duerch Opmierksamkeet fir Detailer aus. Ondsauna Sauna erfëllt Bedierfnesser exzellent, beréiert Wënsch, bezauberet Gefiller an erweckt Neigierecht.

Behind the Design

Press Kit

Credits, team members and technical details provided by the designer.

Unique Properties: Trees grow endlessly upward, a concept reflected in the vertical exterior walls clustered around the sauna room. A spiraling path leads upward to a rooftop relaxation space, mirroring the building's form. The sauna entrance is at GL+250, the cold plunge deck at GL+1000, and the rooftop at GL+3250, so the transition from sauna to cold plunge to open air follows a vertical flow. Viewing the forest at treetop height allows one to share in its growth rhythm.
Dimensions & Packaging: The irregular plan was chosen to allow the passage and expansion of the line of sight and to adjust the degree of intimacy, which was rationally solved by the 150mm CLT floor slab. The elimination of beams has eliminated non-perpendicular joints in the structure, contributing to labor savings in site work. The rational walls of the scale module are discretely assembled and the CLT slab connects them. This structural form itself can be described as a sociopetal structure.
Production Technology: An irregular polygonal floor plan guides sightlines, creating varied scenic views. Research shows conversations are twice as frequent at 90 degrees versus side-by-side. Here, strangers sit together, so we chose obtuse-angled benches to balance interaction and privacy, encouraging conversation without intrusion. Varied seating allows for different levels of interaction, while the overall arrangement around a fire fosters a shared experience.
Inspiration: In a sauna, strangers sit nearly naked in close proximity, creating potential intimacy. Yet in Japan, public saunas haven’t fostered this sense of community. By aligning with Japan’s unique sense of closeness, we aim to create a sociopetal space, encouraging shared understanding without forced intimacy. “Non-intrusive” walls balance connection and separation; their verticality resonates with the forest, while their spacing draws nature in and modulates closeness among neighbors.

Read the Press Release