Sumitomo Forestry Co. Ltd., the timber and forest management arm of the Sumitomo, one of Japan’s largest business conglomerate, plans to build a 350-meter-tall wooden high-rise building. The project, called the W350 Project, is in its conceptual stage and Sumitomo plans to complete it in 2041 to mark its 350th anniversary. This concept plan has been prepared primarily at Tsukuba Research Institute, Sumitomo ForestryÆs research and development facility. The institute is expanding possibilities for wooden buildings as a roadmap for future technology such as the development of building methods, environmentally-friendly technologies, and trees that become resources and building materials.
The aim is to create an environmentally-friendly and timber-utilizing cities where they become forests through increased use of wooden architecture for high-rise buildings. The planned structure is a hybrid wood and steel structure made from 90% wooden materials. It will use a braced tube structure in which steel frame vibration control braces (diagonal braces) are positioned inside a column and beam structure, made from a combination of wood and steel. The outermost side is designed with balconies that continue around all four sides of the building. The balcony part gives the high-rise building a space in which people can enjoy fresh outside air, rich natural elements and sunshine filtering through foliage. The greenery connects from the ground to the top floors through the balcony part, and it offers a view of biodiversity in an urban setting. The interior structure is of a pure wood, producing a calm space that exudes the warmth and gentleness of wood. Nikken Sekkei Ltd collaborated in the design of this building.
The total construction costs of the W350 Plan have been estimated to be almost double that of a conventional high-rise building constructed with current technology. Going forward, the economic feasibility of the project will be enhanced by reducing costs through technological development. The project offers the advantages of the re-use of timber, urban development that is kind for humans, and the vitalization of forestry. Wooden construction will increase through the optimal use of the strengths of trees. We will make every effort to further enhance fire and seismic resistance as well as durability, thoroughly reduce construction costs, develop new materials and construction methods, and develop trees that will be used as resources.