Wooden Skyscrapers Challenge the Conventional Wisdom of the Three Little Pigs
Especially in earthquake-prone Japan, the use of cross-laminated timber (CLT) for high-rise construction may seem counterintuitive, but it's fast becoming the building material of choice.
What’s new: On Friday, January 12, 2024, Mitsui Fudosan, a major real estate developer in Japan, broke ground on a new 18-story high-rise building in the heart of Tokyo's Nihonbashi business district, which will be the largest and tallest wooden office rental building in the country.
Why it matters: The new technology of cross-laminated timber (CLT) is becoming an increasingly popular building material, even for very tall structures such as office and residential buildings that are dozens of stories high. Such structures help address several of the United Nations Sustainable Development Goals (SDGs), including industry, innovation and infrastructure, climate action, and life on land.
By the numbers: Opening in March 2019, Mjøstårnet (Mjøsa Tower) in the Norwegian town of Brumunddal, a two-hour drive north of the capital Oslo, is the world's tallest wooden structure at 85.4 meters (280 feet). But there are even taller wooden structures that will soon dot the skylines of several major metropolitan areas. Even in earthquake-prone Japan, wood is increasingly becoming a common building material for high-rise structures.
When it opens in 2026, Atlassian Central, a 182-meter (597-foot) tall wood-hybrid structure to be built by Obayashi Corporation, will become a new landmark in Sydney, Australia, and take the crown from Mjøstårnet as the world's tallest wooden structure. Other wooden skyscrapers are also planned in Canada and the United States.
In 2022, Obayashi Corporation completed a 44-meter (144 feet) high, 11-story wooden skyscraper in Yokohama that serves as a training facility for its own employees.
Nihonbashi Honmachi 1-chome 3-ban (日本橋本町一丁目3番), the temporary name of Mitsui Fudosan's new wooden skyscraper project that began earlier this month, will have 18 stories above ground. Fire-resistant wood will be used for the building's components, including three-hour fire-resistant laminated wood called "MoenWood" (燃エンウッド). It will be constructed of cross-laminated timber (CLT) panels and steel cladding. The building will also incorporate the latest environmental technologies, such as various recycled products and foil solar panels. Scheduled for completion by September 2026, Nihonbashi Honmachi 1-chome 3-ban will be positioned as an "office you want to go to." The interior furnishings are designed to "let you feel the comfort and warmth of wood with all five senses." Marketing fluff aside, Mitsui Fudosan also plans to conduct empirical research with a research team from the University of Tokyo to find ways to reduce workplace stress through the use of wooden offices.
Sumitomo Forestry has announced its "W350 Plan," a research and technology development concept that aims to realize a 70-story, 350-meter (1,148 feet) tall wooden skyscraper by 2041.
A total of 36 wooden high-rise buildings were built in Japan last year, an increase of 13 from 2022.
Driving the news: Including the global push for decarbonization, more efficient use of forest resources, advances in technology and consumer demand are fueling the growing use of wood in high-rise construction in Japan.
Decarbonization: In October 2020, the Japanese government announced its goal of carbon neutrality by 2050, which calls for reducing total greenhouse gas emissions to zero. This means that total emissions of carbon dioxide and other greenhouse gases, minus the absorption by forests and other sources, will be reduced to zero. In the case of buildings, using wood instead of steel or other materials reduces carbon dioxide emissions because wood requires less energy to produce, process and construct than steel or concrete. According to the Forestry Administration, non-wood structures for office buildings and factories emit 584.7 kg-CO2/m2 while wooden structures emit only 397.3 kg-CO2/m2, and the CO2 emissions of wooden structures are estimated to be 30% to 40% lower than those of non-wood structures. On the other hand, the decline of forest absorption is currently a problem in Japan. Trees absorb carbon dioxide through photosynthesis when they are alive, and the amount absorbed increases as they grow. However, as the trees mature after about 20 years of age, the amount absorbed begins to decline. Most of the cedar and cypress trees used for lumber were planted around 1950-1960, and mature trees over 50 years old make up most of these planted forests today. The amount of carbon dioxide absorbed continues to decline as planted forests age. The amount of carbon dioxide absorbed by forests was 54.3 million tons in 2013 but will decline to only 44.5 million tons in 2020, a decrease of nearly 20%. To promote carbon neutrality, it is necessary to cut down mature trees and use them for building materials, and then encourage the planting of trees on vacant land to restore the carbon dioxide absorption of forests. Therefore, to increase the demand for domestic wood, the Law for the Promotion of the Use of Wood in Public Buildings was enacted in 2010 to promote the use of wood in public buildings and the conversion of public buildings to wooden structures.
Forestry Resources: In resource-poor Japan, dense forests are one of the few abundant resources. Forests cover about 70% of Japan's land area, or 25.76 million hectares (about 67.7 million acres). This area of forest in Japan has remained constant over the past 60 years. However, the volume of tree trunks that make up forests, or "forest reserves," has continued to increase. In 2017, forest reserves totaled 5.24 billion cubic meters (185 billion cubic feet), 2.8 times the 1.89 billion cubic meters (67 billion cubic feet) in 1966. Trees planted in the post-war period, when there were not enough trees, are now ready for use. However, the current situation is that the growing forest stock is not being used. However, due to the declining population, the demand from this sector alone is not enough to fully utilize the growing forest reserves. It is therefore necessary to develop new applications. Increasing the use of wood in commercial buildings will help improve the current state of Japan's planted forests. If profits from the systematic harvesting of planted forests and their use in a variety of wood products are returned to the forests and local economies, it will be possible to promote sustainable and healthy forest development.
New Technology for Earthquake and Fire Resistance: New building materials such as cross-laminated timber (CLT) are structurally strong enough to be used in the construction of skyscrapers. CLT is a large-format wood panel building material that is made by laminating sheets of wood together and then gluing them together so that the grain direction is orthogonal to each piece. Because the wood is laminated and glued at right angles, shrinkage and deformation are suppressed, resulting in dimensional stability and exceptional strength. Originally developed in Austria in 1995, CLT has become commonplace throughout Europe. It is now increasingly common to see CLT on construction sites in Canada, the United States and Australia. In Japan, until 2015, CLT could not be used in buildings without special calculations and strict screening. With the enactment of the Building Standard Law Notification on CLT in 2016, this revolutionary building material can now be used in buildings with only the same calculations and screening as for conventional buildings—even in a country known for its frequent earthquakes. Any of the characters in the fable of the Three Little Pigs would be skeptical that a house (let alone a high-rise) made of wood would be strong enough to withstand the big bad wolf's blowing in the form of a major earthquake, compared to a steel-framed or reinforced concrete building. However, according to the Japan CLT Association, in a shaking table test conducted in 2015 using E-Defense (the world's largest 3D shaking table), test buildings constructed with CLT did not collapse when subjected to an applied force greater than the observed wave (intensity 7) of the Great Hanshin-Awaji Earthquake. CLT is also fire resistant. It burns slowly at a rate of about 1 millimeter (0.06 inch) per minute, and this property can be used to design low-rise, semi-fire-resistant buildings. Large-scale fire-resistant buildings can also be built by cladding CLT with gypsum board or other fire-resistant materials.
What’s next: The biggest challenge in promoting timber construction is cost reduction. If everything from columns, beams, floors, walls and exteriors were made of pure wood, the price would be 30% higher than for steel frame or reinforced concrete construction. At that level of cost, it is not yet viable as a business. For the time being, government subsidies are being used to bridge the gap.
The main problem is the high cost of materials. There are 11 CLT factories in Japan, and transportation costs are also high. If demand for buildings made of wood increases in the future, the number of CLT factories will increase and costs will decrease. If this happens, the unit cost of contracting can be reduced and demand can be expected to increase further, creating a virtuous cycle.
Some companies are making upfront investments in anticipation of future demand growth: Meiken Kogyo, a major CLT manufacturer, reportedly plans to begin construction this year on a distribution center with a large warehouse adjacent to its manufacturing facility.
In 2020, Mitsubishi Estate launched MEC Industry, a joint venture that will build an integrated upstream-to-downstream business model for construction lumber, from production to distribution, construction, and sales. The new company was established to establish a business model that integrates the business flow from production to sales and controls intermediate costs.
"The time will soon come when wooden buildings such as convenience stores, post offices, banks and shops will be built in every corner of the country." - Toshiya Miyazawa, President of a Housing Manufacturer
Knock on wood. If the cost can be made comparable to that of steel-frame or reinforced concrete structures, while ensuring a stable supply chain with high quality, the construction of high-rise wooden buildings will not be just a temporary boom, but has the potential to grow into a major segment of the construction industry.
Links to Japanese Sources: https://frontier-eyes.online/wooden-skyscrapers/, https://pex.jp/point_news/10df675eb30da212f27a3bff05f722ee, and https://www.nhk.or.jp/kaisetsu-blog/700/479145.html
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The argument about CO2 and decarbonization is completely bogus. A lie. A scam.
CO2 is plant food; and, although its levels in the atmosphere have risen a little in recent years, atmospheric CO2 is still at dangerously low levels
"TOP FACTS on CO2 and Net Zero":
https://www.youtube.com/watch?v=9T_9tR1BfzE&list=WL&index=5&t=28s
"The Climate Scam Revealed by COP28":
https://geopolitics.co/2023/12/13/the-climate-scam-revealed-by-cop28/
"Meteorologists, Scientists Explain Why There Is 'No Climate Emergency'"
https://www.zerohedge.com/political/meteorologists-scientists-explain-why-there-no-climate-emergency
There is no excuse for believing in the man-made climate change hoax. None. Like everything else, it's just about power, control and money.