Updated by "Forest Circular Economy" Editorial Board on October 29, 2025, 3:28 PM JST
Editorial Board, Forest Circular Economy
Forestcircularity-editor
We aim to realize "Vision 2050: Japan Shines, Forest Circular Economy" promoted by the Platinum Forest Industry Initiative. We will disseminate ideas and initiatives to promote biomass chemistry, realize woody and lumbery communities, and encourage innovation in the forestry industry in order to fully utilize forest resources to decarbonize the economy, strengthen economic security, and create local communities.
The "Ichigao Mansion Project (tentative name)" promoted by the Yokohama Municipal Housing Corporation has recently been selected by the Ministry of Land, Infrastructure, Transport and Tourism for the "FY2025 Superior Wooden Buildings Promotion Project" (for promotion). This project is the first case of high-rise wooden rental housing constructed by a local housing supply corporation in Japan, and is attracting attention as an attempt to both promote decarbonization and contribute to the local community.
The purpose of this project is to subsidize part of the cost of implementing projects that contribute to the spread of medium- and large-scale wooden buildings with potential carbon storage effects and projects that introduce pioneering design and construction technologies for wood construction, in order to achieve carbon neutrality by 2050. The purpose of the program is to subsidize a portion of the cost of implementing projects that contribute to the spread of medium- and large-scale wooden buildings with carbon storage potential and projects that introduce leading design and construction technologies for wood construction.
The recently adopted "Ichigao Condominium Project (tentative name)" was planned as a realization of efforts to contribute to the "decarbonization" set forth in the City of Yokohama's mid-term plan and the Corporation's mid-term vision. The project plans to conclude an agreement with Taiyo Construction Co., Ltd. to supply six-story wooden rental housing (ZEH-M Oriented level) with high energy-saving performance to the general public.
This is the first time for a local housing supply corporation to construct a high-rise rental housing complex using wood construction. The building uses the P&UA construction method (Panel & Unbonded Anchor Structure System), a technology developed to promote the use of mid- to high-rise wooden structures and to make them more versatile. The building is based on a two-way rigid-frame structure using Japanese cedar and cypress structural laminated timbers, with the first-floor sheathing using a conventional frame structure made of Japanese timber.
The planned site has high visibility facing the station square, and a woody design was adopted to symbolize the shift to a decarbonized society. In response to the fire zone, noncombustible ceramic siding with a wood grain tone is used on the exterior walls and other parts. Environmental considerations are also incorporated in many aspects, such as the use of solar panels and the achievement of "ZEH-M Oriented" insulation performance.
The building also creates a place for community interaction and childcare support. The units are designed with a face-to-face kitchen, a variable floor plan, and a child-friendly design. Before and after construction is completed, the company plans to promote and educate the public about wooden construction technology, decarbonization, and childcare support through tours and a multipurpose space.
This project concretely demonstrates the decarbonization of the building sector and the promotion of the use of domestic timber through the construction of the first high-rise wooden rental housing for a local public corporation. the adoption of the P&UA construction method will be an important milestone in increasing the versatility of mid- and high-rise wooden construction and accelerating the diffusion of the technology.
Outline of Ichigao Mansion Project (tentative name)
Location: 1156-3 Ichigao-machi, Aoba-ku, Yokohama City, Kanagawa Prefecture
Transportation: 3 minutes walk from Ichigao Station on Tokyu Denentoshi Line
Site area: 617.00m2 (registered)
Total floor area: 1,510.70m2 (including multipurpose space)
Building structure: Wooden, partly steel framed, 6 floors
Total number of units: 29 (planned)
Fire resistance: 1st and 2nd floors: 1.5-hour fire resistance, 3rd to 6th floors: 1-hour fire resistance
Completion date: End of January 2028 (scheduled)
Design: First-Class Architect's Office, Taiyo Construction Co.
Construction: Taiyo Construction Co.
Design cooperation: Ichinoura Housing & Planning Co.
Reference Links
First* high-rise wooden rental housing construction project for a local housing supply corporation using the P&UA construction method
Ichigao Mansion Project (tentative name)" adopted as a project to promote the development of superior wooden buildings, etc. - a leading model project that takes into consideration decarbonization and child-rearing (Yokohama City Housing Supply Corporation)
FY2025 Adoption of "Excellent Wooden Building Development Promotion Project"-Projects contributing to the spread of medium- and large-scale wooden buildings with potential carbon storage effects adopted (Ministry of Land, Infrastructure, Transport and Tourism)
