2020 Tokyo Olympics: New National Stadium Construction Plan is Set
On the morning of 12/22/2015, out of two proposals, “Proposal A” was declared the official design plan for the New National Stadium, which will be the main stage for the upcoming Tokyo Olympics. Since this stadium will be visited by people from all over the world, Japan’s technological strengths will be tested by the construction of this building moving forward. Photo: Proposal A (above), Proposal B (below); Ref: 日本スポーツ振興センター
Characteristics of Proposal A
- Title: The “Trees and Green” Stadium
- Harmony with Nature: A project that incorporates an abundance of trees, creating harmony with the greenery around.
- Design Reminiscent of Japan: The roof is made out of wood and iron, and the eaves on the building, which were designed based on rafters often used in traditional Japanese architecture, is especially distinguished.
- Environmental Symbiosis: With the use of rainwater and groundwater, as well as solar powering, this is a structure that has taken long-tern use and the future into consideration.
The total estimated construction cost for Proposal A is 149 billion yen, which is 700 million yen cheaper than Proposal B. Overall the newly estimated cost is significantly lower than the initially estimated number, which was around 250 billion yen. The stadium is scheduled to be completed at the end of November 2019.
CLT Construction Method
While it has not been a popularly used construction method in Japan up until now, there has been aggressive consideration to introduce a wood building technique called the CLT method into the construction of several Tokyo Olympic facilities, as well as the Olympic Village where participating athletes, officials, and trainers will be housed. CLT stands for “cross laminated timber,” which is a construction method where pieces of wood that are several centimeters thick, are stacked crosswise at a right angle to one another.
Reasons to Actively Incorporate the CLT Method
1. Shorter Construction Period
Since many buildings need to be constructed in the short period between now and the Tokyo Olympics, it is vital that work get done quickly. Since the CLT method is just stacking wooden panels on top of each other, the construction process can be sped up by about 40% compared to buildings using concrete.
2. Dreamy Construction Techniques
This technique is superior to concrete or steel in various aspects, such as durability, earthquake resistance, heat insulation, sound insulation, etc. In addition, since it is thick it can prevent the spread of flames in case of a fire. As a country that suffered the Great East Japan Earthquake of 3/11, Japan utilizes lessons learned from that disaster to cover all bases on earthquake resistance for the future. The weight is also much lighter, and is 1/6 of what it would typically be. It seems that because of this technique, the wooden high-rise buildings that were said to be impossible are now possible.
3. Local Creations
Since they are using wood, at first glance you may be concerned with the negative environmental impact, however this process actually supports the natural cycle of logging and new growth. This then leads to the rebuilding of the local forestry.
This brand new construction technique, the CLT method, has been approved for the second building for Henn na Hotel in Nagasaki Huis Ten Bosch, whose construction is moving along steadily.