TOILETOWA is an architecture of circulation and regeneration that makes this visible. More than just a toilet, it was built as an environmental education space attached to the headquarters of Ishizaka Corp in Oak Forest, which recycles industrial waste and serves as a model for a future waste-free, recycling-oriented society.
It is a wooden building consisting of a toilet building with a circular rammed earth wall made of recycled soil NS-10 developed by Ishizaka Corp,, and a tank building that shows the process of perfect recycling and circulating wastewater by combined fermentation of microorganisms.
To reduce the environmental impact, the foundation is made of crushed stone instead of concrete. – Made using wooden stakes. With the theme of recycling in the materials used, the interior walls and earthern floors of the toilet building are made of almost recycled materials of soil, wood, and glass. The hand wash and toilet bowls are also made of recycled wood chips.
Toilet wastewater is not only completely recycled and reused but also used as agricultural water to promote the growth of surrounding garden crops. Furthermore, by using natural materials around the building to “regenerate the earth” and allowing water and air to pass through the soil from the ground, the forest in the area has been regenerated, creating a refreshing air and atmosphere. The wooden construction was hand-carved by young carpenters, making use of plastering techniques such as rammed earth, plastered walls, hard-packed earthern floor, and mortar polishing counter, and not only the materials but also the circulation of traditional architectural techniques of wood and clay.
______ Photo, takeshi noguchi
Drawings, Tono Mirai architects
The structure is crafted predominantly from materials that either “return to the earth” or are recycled, avoiding the use of concrete.
Two semicircular rammed-earth walls, composed of repurposed soil and placed in staggered formation, create a gentle movement and a sense of circulation within the forest setting. With light streaming in from skylights, the entire building acts as a “well of light,” connecting the sky and the earth.
The primary material used, NS-10, is a recycled soil developed in collaboration by the building owner, Ishizaka Sangyo, and IS Engineering. Derived from the deconstructed gypsum boards and soil mixtures from housing materials brought to Ishizaka’s facilities, this material is sorted and refined at the company’s factory. Previously, it was used solely as a paving subgrade material, but in this project, it was innovatively employed as a construction material.
Due to limited compressive strength, the recycled soil was not used independently as rammed-earth structure; instead, it was incorporated as a finish around a timber frame, with slaked lime mixed in and compacted to form inner and outer rammed-earth walls, each 75mm thick, resulting in a combined 294mm thickness. Further, slaked lime was mixed with the soil to create traditional *sanwa-do* floors and applied as plaster mixed with slaked lime for interior partition walls, testing the full potential of this recycled soil.
Cobined fermentation has been used in Japan for over 20 years, and here we aim to show the mechanism of water circulation in a sophisticated design as a showcase for the recycling society of the 21st century.
While retaining the existing trees, the complex fermentation process of the fermentation layer, synthesis layer, and catalyst tank is arranged in an arc, expressing the circulation of water with raised beds (three-dimensional vegetable garden) facing a circular courtyard.
In order to keep the overall scale down, the roof has a 2/10 slope on the courtyard side, and the tank can be seen by removing the blind door. The exterior wall is inspired by Local landscape of the forest(Musashino’s Satoyama), and is made of prefecture-produced cedar boards of different widths pasted randomly.
Wood Long Eco, a wood protectant derived from natural materials, is applied to each piece, and each piece changes to a different color as it ages with UV rays. Through the gaps between the boards, people can see sunlight filtering through the trees and see the actual forest, creating a landscape that blends in with the forest.
A biotechnology called combined fermentation (EMBC) developed by Dr. Yasuhide Takashima is used to treat and regenerate this toilet wastewater. By allowing aerobic bacteria and anaerobic bacteria to coexist, co-prosperate, and coexist, changes in fermentation, decomposition, fermentation synthesis, and fusion occur, and the water is purified and contains zero bacteria, malignant bacteria, and E. coli, making it odorless. Clear enough to drink. The enzyme water created in this process circulates endlessly, and the water containing enzyme-bound crystals activates the soil and has the effect of improving crop productivity.
Along with the construction of this toilet, the surrounding forest and soil were weakening, so WAKUWORKS carried out work to “regenerate the earth” of the forest, centering on the toilet, as part of the work to regenerate the forest along with the exterior maintenance.
Plants and plant-derived materials that can be found on the site, such as tree branches, fallen leaves, bamboo charcoal, and charcoal, are buried vertically and horizontally in the soil to create water veins and air flow underground, which aggregates the soil. It activates the functions of the mycelium, root system, microorganisms, and living organisms in the soil, cultivating the inherent power of the soil.
Recycled crushed stone tiles were used to catch rain, and wood chips and lava stone Asama were used for the sidewalks. Through this work, the soil, which was hard and poorly drained, has been cleared of puddles, and as the trees have regenerated, there has been a refreshing breeze, and it is possible to feel that a circulation of water and air has been created in the forest: earth, wood, architecture, and earth.
Trees are also called “pillars of water,” and they absorb water from the water veins in the soil and emit water vapor from their leaves. Through this earth regeneration project, an invisible water cycle between the soil and the air was realized, and the forest ecosystem was regenerated along with the water cycle of the toilet’s complex fermentation.
NHK WORLD-JAPAN 2024.04.25
New Public Restroom Designs
https://www3.nhk.or.jp/nhkworld/en/shows/2101024/
architecturephoto
https://architecturephoto.net/205035/
TECTURE MAG
https://mag.tecture.jp/product/20231012-100056/
ArchDaily
https://www.archdaily.com/1015881/toiletowa-wc-tono-mirai-architects
Archello
https://archello.com/project/toiletowa
gooood
https://www.gooood.cn/toiletowa-by-tono-mirai-architects.htm
WABISABI
https://www.instagram.com/p/DDTTASdsjjC/?img_index=1
dezeen
https://www.dezeen.com/2024/05/03/toiletowa-tono-mirai-architects-japan/
Bio toilet / Combined fermentation system / the recycling society / curve / Rammed earth / Sanwa soil / Mortar grinding / Wooden architecture
Name — TOILETOWA
Location — Miyoshi Town, Saitama Prefecture
Owner — Ishizaka Sangyo Co., Ltd.
Primary Use — Bio-Toilet
Construction Type — New Build
Zoning Area — Urbanization Control Area, Park Facility
Designer — Mirai Tono, Tono Mirai Architects
Facilities — GEN JAPAN, Marunaka Equipment Industry
Supervision — Mirai Tono, Tono Mirai Architects
Name Design — TSDO, Taku Sato
Construction — Terashima Construction
Facilities — GEN JAPAN, Marunaka Equipment Industry
Exterior — WAKUWORKS
Site Area — Park Facility
Building Area — 9.9㎡
Total Floor Area — 9.9㎡
Maximum Height — 2.68m
Eave Height — 2.22m
Wooden 1st story
Clasher run・Burned wood pile
Design Period — January 2021 to March 2023
Construction Period — March 2023 to August 2023
Exterior — Recycled Tile Aggregate, Wood Chips, Asama Stone
Flooring — Recycled Soil NS-10 (Ishizaka Sangyo), Traditional Sanwa-do Flooring
Exterior Wall — Recycled Soil NS-10 (Ishizaka Sangyo), Rammed Earth Finish
Roofing — Galvalume Steel Sheet, t0.35 (Yodogawa Steel), Silver-Black Color “Kizashi”
Interior Wall — Recycled Soil NS-10 (Ishizaka Sangyo), Plaster Finish, Reused Wooden Boards
Eaves and Ceiling — J-Panel, t30, Exposed Timber Framework
Openings — Skylight by VELUX, Model FCM
Toilet — Woodio, Wood Block, Color: Polar
Hand Basin — Woodio Soft 40, Color: Polar
Faucet — SANWA AQUAPIA KT0721C
Exterior and Flooring — Recycled Tile Aggregate, Wood Chips, Asama Stone
Interior and Exterior Walls — Saitama Prefecture Cedar Boards, t15, w75/90/105 (supplied by Okabe Lumber Store), Vertical Random Pattern with 9mm Reveals
Wood Protection Finish by Wood Long Eco (Ogawa Kotaro ∞ Yuriko Co.)
Exterior Wall — Recycled Soil NS-10 (Ishizaka Sangyo), Rammed Earth Finish
Roofing — Galvalume Steel Sheet, t0.35 (Yodogawa Steel), Silver-Black Color “Kizashi”
Eaves and Ceiling — J-Panel, t30, Exposed Timber Framework
Fermentation System — Composite Fermentation Equipment (Takashima Development Engineering)