This is a retail facility adjacent to the EXPO 2025 (Osaka, Kansai) Arena. Since the Expo site was constructed on coastal reclaimed land, it was proposed that an architectural structure be built by upcycling marine plastic waste. Marine plastic pollution severely impacts ecosystems worldwide and is recognized as a shared global issue. The aim of this architectural project is to promote the concept of a circular economy at the Expo site, where visitors from all over the world will gather. The building, including its foundation, is designed for easy assembly and disassembly with plans for relocation or reuse as furniture after the Expo concludes.
The upcycled marine plastic waste panels, which are used as exterior material designed to mimic a school of fish swimming in the blue sky, soften the harsh summer sun and create a space dappled by sunlight. These exterior panels are made entirely from 100% recycled marine plastic waste and have been produced with a degree of purity comparable to that of commercially marketable products released only after undergoing all kinds of rigorous testing, including material strength testing, wind tunnel experiments, and exposure testing. The panels, each of which embodies the Earth composed of land and water, have been designed with the aim of giving off a strong message. The marine plastic used includes waste collected from the coast of Tsushima in Nagasaki Prefecture, as well as other coastal areas in Japan. In total, 5,000 panels were produced, equivalent to approximately 30,000 plastic bottles.
Located at a windy coastal site, the structure has an exterior system consisting of panels that freely turn with the wind so as to reduce the wind load on the building. By offsetting the suspension points of SUS (stainless steel) wires, the design achieves a scale-like form—resembling fish scales—that stabilizes at angles less than 15 degrees relative to the wind direction. Through repeated wind tunnel testing, improvements were made to the structural and mounting methods, resulting in an exterior capable of withstanding wind speeds of up to 40 m/s. The tension of the wires can be adjusted using clamping nuts at the base.
The structure uses simple, low-cost pipes designed to be reused after the Expo concludes. In this project, the pipe connection details were considered a key design element. To achieve a building that doesn't feel temporary, a minimal and stylish clamp was developed using precision-machined stainless steel. The system consists of multiple parts joined together and is designed to be assembled and disassembled manually.
The floor was finished with reed chip pavement. We realized the importance of periodically cutting off reeds because they are capable of improving water quality. With the aim, therefore, of protecting the river environment through the local production and local consumption approach, we used reed cuttings taken from the reed beds in the Udono area along the Yodo River in Osaka and developed a method for using reeds as pavement material. The vivid warm color of reeds accentuates the building, and the soft and comfortable rug of reeds helps create a relaxing space for visitors.
