Tokyo-based Sumitomo Forestry Co. has unveiled plans to develop and build a 1,148-foot wooden high-rise to commemorate the firm's 350th anniversary in 2041. Called the W350 Plan, the research and development concept for the 350-meter tower honors the company's founding in 1691, when the Sumitomo family first used timber to fortify its copper mines.
The plan calls for a hybrid wood-and-steel structure that will be supported by a braced tube apparatus made of steel frame vibration-control braces. Balconies will run across all four sides of the exterior, along with greenery that will extend through the balconies from the ground floor to the upper levels. The interior structure, designed in collaboration with Nikken Sekkei, will be entirely wooden.
Through its development and execution of the W350 Plan, Sumitomo aims to improve its materials, resources, and building capabilities to the point where the finished product can be used as model for “environmentally friendly and timber-utilizing cities.” According to the concept, cities would become more like forests as they expand their use of wood construction and greenery cover, creating a comfortable environment for living beings and spurring an increase in biodiversity.
In addition, the increased use of wooden architecture would spur a demand for timber and drive increased carbon dioxide absorption.
At present, according to Sumitomo, Japan’s forests cover 68.5% of the country's land area, but its self-supply rate for domestically produced timber is about 30%. As wooden construction grows, Sumitomo estimates the increased demand for timber will promote forest maintenance and replanting, ensuring the forests’ sustainability and increasing their carbon dioxide absorption volume.
The W350 building will cover 455,000 square meters (about 1.5 million square feet) of retail, residential, office, and hotel space across 70 stories. Current construction estimates call for 185,000 cubic meters of timber and a total construction cost of approximately 600 billion yen ($5.6 billion), or about double the current cost of a conventional high-rise in Japan. Sumitomo expects that technological development will reduce the cost of future wooden high-rise projects.
