The Japanese National Stadium, the host of the 2020 Summer Olympics and Paralympics, is a multipurpose stadium in the heart of Shinjuku, Tokyo, Japan. This national stadium serves as a beacon of traditional Japanese architecture blended with nature. The Japan national stadium is a splendid example of an amalgamation of tradition, climate, and technology. Basking in the huge arena of the space, the Japan national stadium that we see now rose from the remains of the earlier demolished stadium that was built in 1958. The stadium was set to be redesigned to create a new and larger capacity stadium.
With the old stadium being demolished in 2015, the design for the new stadium to be built took a few years to be finalized due to the increase in building costs. The Japanese prime minister Shinzo Abe scrapped the original plans in May 2015 until Kengo Kuma was chosen to design the national stadium in December 2015. As a result, the national stadium was not available for the 2019 Rugby world cup as originally intended. The Japan national stadium was completed in 2019 and designed by AZUSA SEKKEI, Kengo Kuma and associates, and Taisei Corporation. The overall footprint of the Japan national stadium is 192000 square meters.
The concept of the national stadium was created to resemble the surrounding natural environment. With a seating capacity of 68000, the main structure of the national stadium consists of reinforced concrete and steel, with a sheltered roof made from steel that is enveloped with laminated larch and cedar trusses. The cedar panels clad the eaves of the seating arena from all sides of the stadium. The aspect of using cedar wood resonates with the style of Japanese architecture along with planters on the edge of the cantilever to establish a connection between the inside and outside environment. The multi-layered eaves on the exterior of the structure facilitate in blocking harsh rays of sunlight and bringing a pleasant breeze to the three tiers.
Additionally, the height of the stadium was minimized to amalgamate the rich greenery of the Meiji Shrine’s outer garden. Hence, the cantilevered space acting as a passage to the three tiers enveloped by the eaves was vegetated with native species. These green edges at every level contain 47000 plants that are visible from the exterior. The enormous, flat, cantilevered roof is created from 60 meters long frames made of local wood and steel. The cedar eaves used for cladding are collected from 46 prefectures of Japan and Ryukyu pine from Okinawa. According to traditional Japanese architecture, the overhanging eaves were designed as a contemporary illustration of the wooden Japanese buildings.
The pinnacle of the design of the national stadium revolves around the meticulous utilization of the structure to counter the effects of the climate. The grand eaves of the wind (or as it is known in Japan, “Kaze no Obisashi”) improves the thermal environment of the tiers and the field by efficiently bringing in seasonal winds while carrying the heat and humidity from inside the stadium to the top. The spacing between the lattices of the eaves is designed as per the orientation of the building. The eaves on the south-southeast side are narrower to capture the summer breeze by directing it to the stands, whereas the north side is kept wider to divert the winds in the cold season by directing it inside the roof. This helps in cooling the building in hot weather as opposed to airflow creating fans and mist cooling systems. The wood accent of the Japan national stadium used in the interior spaces nurtures a warm and tangible environment. Furthermore, wood has been used in interior and exterior spaces that include the athlete’s dressing rooms and the seating areas in the recreational space. Considering the aspect of universal design, the national stadium houses 450 places for wheelchair users.
The Japan national stadium is equipped with solar panels on the roof to generate electricity along with rainwater harvesting points in underground cisterns that are used to irrigate the green spaces in the arena. The design of the stadium explores a superior structural presentation to achieve structural stability and workability within the limited period of construction. The large cantilever roof and the stands were built with a simple steel frame, by repetition of the same truss in a circumferential direction. The foundation was constructed heavily with precast pre-cast materials that were used in the making of the spectator’s seat as well. The national stadium was made to be earthquake-proof by employing a soft first-story damping structure, the lower level of the stadium, with the use of oil dampers.
The Japan national stadium was sought to be featured in the numerous architecturally significant venues to host the Olympic games. The interior spaces of the stadium are brimming with the most interesting activities. Aside from the traditional materials, the impression and significance of Japan’s culture and art are impressive. Located on the ground floor is a flash photography zone where the walls are laden with phrases such as “Tokyo, Japan” and “National stadium” written in calligraphy by Japanese artist, Bisen Aoyagi. The Olympic Torch is displayed in the same space that traveled through Japan’s 47 prefectures. Furthermore, one of the most beloved icons of Japan, the cauldron from the 2020 opening and closing ceremonies is displayed outside the stadium next to a blooming cherry blossom tree designed by Canadian-Japanese designer Oki Sato.
- Dezeen [online]
Available at: https://www.dezeen.com/2021/07/28/japan-national-stadium-kengo-kuma-tokyo-olympics/
- Archdaily [online]
Available at: https://www.archdaily.com/964848/japan-national-stadium-taisei-corporation-plus-azusa-sekkei-plus-kengo-kuma-and-associates
- Timeout [online]
Available at: https://www.timeout.com/tokyo/news/you-can-now-visit-the-japan-national-stadium-041322