Ishizaka Inc. has built a bio-toilet called “TOILETOWA” that recycles everything.

Ishizaka Inc. (Headquarters: Miyoshi-machi, Saitama Prefecture; President: Noriko Ishizaka) has constructed a fully recycling bio-toilet called “TOILETOWA” (designed by Tono Mirai architects; named by TSDO Inc.; Note 3) within Santome Konjakumura, an environmental education field. The toilet is surrounded by earthen walls made solely of 80% or more of the recycled material NS-10 (Note 1) reclaimed from construction waste and slaked lime.

◆ Project Overview

“TOILETOWA” was born as a fully recycling bio-toilet that does not waste any water, inspired by a strong desire to revive the cycle that has continued since the Edo period and to convey the importance of microorganisms essential for soil development.
The construction of this toilet was realized through the integration of bio-architects and biotechnology under the supervision of JINOWA (Note 4), an international soil restoration company consortium based in Italy. Going forward, this bio-toilet will serve as a starting point for the development of unprecedented experience programs.

◆ Features of the bio-toilet building made with recycled materials:

The toilet building itself is constructed using wooden framework construction. The construction was carried out by Terashima Construction (Note 5), a company renowned for its traditional Japanese carpentry skills, including those used in temple and shrine construction. The finished wall is made of 27 layers of rammed earth, carefully hand-hammered and layered. This is the culmination of the advanced plastering techniques of Japan, registered as one of the “Traditional Architectural Craftsmanship Skills”(Note 6) by UNESCO as an Intangible Cultural Heritage.

The sanitary fixtures are the first in Japan to feature products from Finland’s Woodio (Note 7), a waterproof 100% wood composite material developed using Scandinavian technology.

Recycled wood is also used for the toilet partitions and counters.

The wastewater is recycled using a Japanese biotechnology called complex fermentation technology (provided by the Takashima Development Engineering Research Institute (Note 8)). This technology safely ferments, decomposes, and synthesizes wastewater using microorganisms, producing treated water containing enzymes with environmental regenerative properties, making it 100% recyclable. The treated water has also been shown to improve soil health and promote plant growth. In addition to being recycled for use in toilet flushing, environmental studies are planned for the woods within the facility’s management site.

The area around the toilets is being treated with land regeneration technology utilizing leaf compost from Musashino, a designated Globally Important Agricultural Heritage System (GIAHS), and existing resources. The landscape design, with technical guidance from WAKUWORKS Co., Ltd. (Note 10), improves the flow of air and water in the soil and restores the satoyama landscape.

Ishizaka Inc., which operates an industrial waste intermediate treatment plant and the environmental education field “Santome Konjakumura” that implements the SDGs, sees the “TOILETOWA” as the first milestone in implementing the vision of “Zero Waste Design” (Note 11). The company aims to go beyond sustainability to achieve regeneration, creating a circular economy in which all land resources are recycled.

(Note 1) NS-10 Construction Technology Review Certification: Fill material made from recycled soil and sand contained in construction waste
https://www.jacic.or.jp/jacic-hp/node/19214 

(Note 2) Tono Mirai architects (Karuizawa City, Nagano Prefecture) 
https://www.tonomirai.com/ja/ 

(Note 3) TSDO Inc. 
https://www.tsdo.jp/ 

(Note 4) JINOWA International Soil Restoration Enterprise Consortium (Italy) 
https://www.jinowa.org/ 

(Note 5) Terashima Construction (Nagano City, Nagano Prefecture) 
https://trsm-bco.jp/ 

(Note 6) Intangible Cultural Heritage Plastering (Japanese Wall) 
https://bunka.nii.ac.jp/special_content/intangible/125591 

(Note 7) Finnish sanitaryware Woodio (Helsinki) 
https://woodio.fi/en/ 

(Note 8) Takashima Development Engineering Research Institute Co., Ltd. (Numazu City, Shizuoka Prefecture) 
https://y-takashima.jimdofree.com/ 

(Note 9) Musashino Leaf Compost (certified as a Globally Important Agricultural Heritage System) 
https://www.town.saitama-miyoshi.lg.jp/news/2023-0706-1243-34ochibataihinouhou.html 

(Note 10) WAKUWORKS Co., Ltd. (Kunitachi City, Tokyo) 
https://www.wakuworks.jp/ 

(Note 11) Ishizaka Inc.’s “Zero Waste Design” Vision 
https://ishizaka-group.co.jp/vision/vision

Please see the press release below. 
“Ishizaka Inc. has built a bio-toilet called “TOILETOWA” that recycles everything. (PDF)” is here