wonderwall, the architecture and interior design firm founded by masamichi katayama, has completed a public convenience as part of the‘tokyo toilet’project. located inside the city’s ebisu park, the concrete structure has been designed to unobtrusively occupy the site in a welcoming manner. ‘we kept in mind a facility that distances itself from architectural concepts and elements: an object that stands casually in the park as if it were playground equipment, benches, or trees,‘says masamichi katayama.

all images by kozo takayama
titled‘modern kawaya’, wonderwall’s design references the toilets used in the country in neolithic times. ‘in japan, the origin of toilets is kawaya, written initially as 川屋 and later 厠 (also pronounced kawaya),’ masamichi katayama continues. ‘kawaya was a hut (ya 屋) that stood over the river (kawa 川) dating back to the neolithic times of early jōmon period (10,000 to 6,000 BCE). these huts were of primitive and simple designs, often made of hardened soil or pieces of wood bound together.’

the design team drew from the typology’s ancient origins to create a structure comprising interlocking concrete walls.‘trying to envision the appearance and atmosphere of the primitive kawaya of the past, we built an‘ambiguous space’that is simultaneously an object and a toilet by randomly combining 15 concrete walls,’ explains masamichi katayama. ‘the spaces between the walls lead users into three different areas designed for men, women, and everyone.’

this project by the nippon foundation aims for the realization of a society where all kinds of diversity are accepted, by building public toilets. with the full cooperation of shibuya city, 17 toilets that are accessible for anyone regardless of gender, age, or disability will be created. through the power of design and the creativity of 16 creators who support the objectives of this project, the nippon foundation is demonstrating what this new society can achieve. the toilets will be constructed by daiwa house industry co., ltd., while toto ltd. will advise on toilet equipment and layout.










project info:
name: modern kawaya — tokyo toilet
location: ebisu park, tokyo, japan
design: wonderwall/masamichi katayama
client: nippon foundation
status: complete/open
photography: kozo takayama