Ondsauna Sauna by Taro Shimokawa is a highly esteemed winner of the very prestigious 2025 A' Design Award Perunggu in Desain Arsitektur, Bangunan dan Struktur Competition Category.

PerungguArsitektur· 2025

Ondsauna Sauna

by Taro Shimokawa

Client: Ondpark

A' Design Award Perunggu Winner in Arsitektur 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 adalah sebuah bangunan sauna yang ditempatkan di tengah hutan. Dinding-dinding eksterior vertikal dikelompokkan mengelilingi ruang sauna, menggemakan pertumbuhan pepohonan yang menjulang ke atas. Sebuah jalur melingkar menuntun pengunjung ke ruang relaksasi di atap. Pintu masuk berada 250 milimeter di atas permukaan tanah, dek untuk berendam air dingin pada ketinggian 1000 milimeter, dan atap pada 3250 milimeter, sehingga perpindahan dari sauna ke kolam air dingin lalu ke udara terbuka bersifat vertikal. Denah poligonal tak beraturan dan bangku bersudut tumpul mengarahkan garis pandang serta memungkinkan pengunjung memilih tingkat interaksi yang mereka inginkan.

The Recognition

About the A' Design Award Perunggu

Ondsauna Sauna adalah pemenang A' Design Award Perunggu, pengakuan yang sangat bergengsi yang diberikan kepada desain luar biasa yang dicirikan oleh kreativitas, kecerdikan, dan ketajaman. Pemenang Perunggu adalah artefak yang sangat terampil dan sangat kreatif yang membuktikan pengalaman luas, imajinasi, dan kelihaian para desainernya. Ondsauna Sauna diharapkan menjadi objek yang sangat dihargai, dikagumi, dan dicintai, sangat profesional dan inovatif. Desain pemenang A' Design Award Perunggu ini menyertakan praktik terbaik dalam seni, sains, desain, dan teknologi, dan sangat baik dalam perhatiannya pada detail. Ondsauna Sauna memuaskan kebutuhan dengan indah, menyentuh keinginan, memikat perasaan, dan menarik rasa ingin tahu.

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