Cedar panels adorn the cornice of Japan’s 68,000-seat National Stadium, which Japanese studio Kengo Kuma and Associates designed for the 2020 Tokyo Olympics.
The Meiji-Jingu Park building in Tokyo, created by Kengo Kuma and Associates with Taisei Corporation and Azusa Sekkei Co, hosted the opening ceremony last week and will host track and field events for both the Olympic and Paralympic Games.
Completed in 2019, on the eve of the rescheduled games due to the coronavirus, the stadium is shaped like a large oval.
Its main structure is made of reinforced concrete and steel and protected by a steel roof with laminated larch and cedar trusses.
The roof is pierced by a huge oculus over the track, but cantilevered to shelter three tiers of spectator seating.
Behind the seats are circulation areas that span the edges of each level and contain 47,000 plants. This greenery is visible from the outside and was designed so that the stadium blends in with the surrounding greenery.
To reduce the visual impact on the facility, the height of the stadium was minimized through a combination of a flat roof and a compact seating arrangement.
Externally, the building is distinguished by a series of cedar-clad cornices collected from each of Japan’s 47 prefectures.
The eaves were designed by Kengo Kuma and Associates as a modern interpretation of the overhanging eaves of traditional wooden Japanese buildings.
They also have functional benefits, protecting against sunlight and rain, promoting air circulation and penetration of the prevailing wind. This helps to cool the building in hot weather in tandem with fans creating airflow and a fog cooling system.
Wood is also used inside the Japanese National Stadium, where it lines the interior spaces to create a warm and tactile atmosphere. It has also been used to furnish the athletes’ locker rooms and create benches in the seating areas.
The stadium is equipped with more than 450 wheelchair spaces, solar panels on the roof that generate electricity, and rainwater collection points in underground cisterns that are used to irrigate the arena’s greenery.
The Japanese National Stadium was featured in our review of architecturally significant places where games take place, next to structures by Japanese architects Kenzo Tange and Fumihiko Maki.
We also featured the stadium during the Dezeen Virtual Design Festival last year, when architecture video blogger Martin van der Linden called it “pretty simple and definitely not iconic.”
When the Japan National Stadium first opened in 2015, it sparked controversy as it replaced a proposal by British architect Zaha Hadid that was canceled due to rising prices and opposition.
It came under fire again in 2017 because tropical hardwood associated with deforestation and human rights violations was used as the mold for its concrete elements. This is one of the reasons why the Tokyo 2020 Olympics have been accused of promising to be the greenest Olympic event in history.