Showa Gakuin Elementary School West Wing

The Showa Gakuin West Building is an extension constructed to accommodate the growing enrollment at an existing elementary school. In Japan today, trees planted on a large scale from the postwar period through the era of rapid economic growth have reached the stage where they are suitable for use as building materials; consequently, maintaining a proper cycle of harvesting and reforestation to protect forest resources has become a pressing social issue. We at Nikken Wood Lab—a team at Nikken Sekkei specializing in the development and research of wood-based and timber-frame construction—sought to pursue sustainability through the use of domestically sourced timber and explore new possibilities for CLT (Cross-Laminated Timber)*, a type of mass timber, in this project. The site is located in the central area of a town featuring a 2-kilometer-long avenue of cherry trees along the Shinma River, and is situated in the heart of a “corridor of water and greenery.” To meet urban planning restrictions regarding height and landscape, as well as to align with the access levels of the existing school building, we adopted a “CLT two-way flat slab construction method” without beams. This approach allowed us to maintain the same ceiling height as the existing building while minimizing floor-to-floor heights and overall building height. Furthermore, by utilizing CLT to reduce the weight of the superstructure and minimize the load on the foundation, we were able to shorten the construction schedule.