Japanese architecture practice Yano Aoyama Architecture Design has completed the Tobe Zoo Toilet in Ehime Prefecture, creating a compact public facility that combines sculptural concrete forms with a naturally curved cedar canopy. Located at the entrance to Tobe Zoological Park, the project replaces outdated amenities with accessible restrooms while demonstrating how small-scale civic architecture can elevate the public realm through thoughtful material innovation.
Curved cedar canopy defines sculptural public architecture
The project comprises two cubic concrete volumes, each measuring two by two metres, which house separate public toilet facilities equipped with accessible amenities and baby-changing stations. Rather than treating the commission as purely functional, the studio developed an architectural form that responds to both the zoo’s entrance and its surrounding landscape.
“The gentle roof curve echoes the ‘bridge’ motif of the existing entrance facilities, themselves a reference to the Seto Ohashi Bridge, a remarkable piece of engineering that established the first land connection between the islands of Shikoku and Honshu,” the studio told.
“The result is not a closed object, but a small piece of public infrastructure that behaves more like a natural canopy forming an open, light, and welcoming space at the zoo entrance,” it added.
The exposed concrete blocks feature chiselled exterior surfaces that introduce texture and contrast with the sweeping timber roof. Meanwhile, large square roof openings bring daylight and natural ventilation into the interiors, reducing the need for artificial lighting during daytime hours.
Local cedar and natural timber movement shape the design
A defining feature of the project is its 12-metre-long cross-laminated timber (CLT) roof, manufactured from locally sourced Ehime cedar. Instead of resisting the timber’s natural tendency to bend under its own weight, the architects embraced the material’s behaviour during construction.
The studio intentionally applied controlled loading to encourage the roof into a gentle curved form before supporting it with slender steel columns around its perimeter. Consequently, the roof transforms a structural characteristic often viewed as a defect into the project’s central architectural expression.
A curved gutter follows one edge of the canopy, while traditional rain chains direct water into drainage channels beside a planted garden, reinforcing the connection between architecture and landscape.
“Rather than treating CLT as a neutral industrial board, the design plays with the natural behaviour of timber, especially its tendency to deflect under its own weight, to enhance its physical properties,” explained.
“Normally, deflection is considered a problem to be corrected during transport, fabrication, or construction. In this project, it becomes the central architectural idea,” it added.
“This gesture is both technical and poetic: the roof is shaped by the material’s own physical nature, and its quiet curve resonates with the surrounding landscape and the memory of the bridges.”
By combining exposed concrete, locally sourced cedar and passive environmental strategies, the Tobe Zoo Toilet demonstrates how carefully considered design can transform everyday public infrastructure into a distinctive architectural landmark while responding sensitively to its cultural and natural setting.