Reader Response Draft 3: Port Plus Obayashi Yokohama Training Centre

The article, “Will Pure Wooden High-Rise Building Be a Game Changer for Decarbonisation, Obayashi Corporation’s Challenge” by Clark (2023), examines how Obayashi Corporation employs wooden construction to create competitive buildings with a smaller carbon footprint. The Port Plus Obayashi Yokohama Training Centre, a showcase of the Obayashi Company's wooden construction, uses cross-laminated timber (CLT) and laminated veneer lumber (LVL) as key structural elements. What sets the Port Plus apart from similar buildings is the implementation of rigid cross joints, which bind columns and beams using glued-in rods (GIR) and a Japanese carpentry technique known as Nuki (Port Plus, n.d.), which involves fitting a precut section of lumber into a similarly sized hole cut on another section. Another feature of Port Plus is the use of "O･Mega Wood" which offers fire resistance and earthquake protection comparable to traditional buildings that are made of concrete and steel. (Obayashi, 2016). Especially in an earthquake-prone country like Japan, wooden construction can provide a comparable alternative to steel and concrete. The adoption of all-wood construction is a step towards achieving Japan's environmental goals. Clark revealed that the government's budget allocation to support decarbonisation including funding for the construction of Port Plus highlights the Japanese government's commitment to its 2050 net zero emissions target (Statement by Prime Minister's Office). 

 

Fully wooden buildings like the Port Plus is the potential to positively impact sustainable construction. The use of only wood can be used to reduce the environmental impact of construction, compared to concrete and steel, without compromising features like fire and earthquake safety. However, there is an argument to be made that the cost of these buildings outweigh the potential benefits. 

 

One advantage of fully wooden construction is the reduction of carbon emissions compared to comparable concrete and steel constructions because of the materials used. According to Bahrami et al. (2022), wood only emits 90 kg of CO2/m3 as compared to steel, at 209 kg of CO2/m3 and concrete at 602 kg of CO2/m3. Incidentally, the Port Plus building emitted 1700 tonnes of CO2 less than a comparable concrete and steel building (Port Plus, n.d.). Other than carbon emissions, using wood can also help to maintain the functions of a forest, including water regulation against flooding, landslide prevention and water filtration, which decline with age (Port Plus, n.d.). Morgan (2019) reported that old forests store between 950 million to 1.11 billion metric tonnes of carbon per year while young forests store between 1.17 to 1.66 billion metric tonnes per year. Therefore, the regular maintenance of forests allow the potential of fully wooden construction to be fully realized.  

 

Another advantage of fully wooden buildings like the Port Plus are also comparable to their steel and concrete counterparts in fire and earthquake safety. The pillars and beams in the building have a three-hour fire-resistance certification due to their triple-layer construction (Port Plus, n.d.), which is on par with Japanese regulations (Building Research Institute, 2011). A full-scale model of the Port Plus was also able to survive a simulated magnitude 7 earthquake without structural damage (Clark, 2019), where according to Rafferty (2023), a magnitude 7.0 to 7.9 on the Richter scale is classified as "serious damage over large areas". Hence, there are no issues with the safety of a fully wooden building like the Port Plus. 

 

At the same time, the cost of constructing such buildings exceeds that of their steel and concrete counterparts. According to Woodcentral (2023), the Port Plus costs 30% to 40% more than its counterparts due to costly processes and the strict building criteria in Japan, specifically in expenditures to meet anti-fire criteria. Another reason for this price difference might be from the so called "Wood Shock" (The Japan News, 2022) that saw lumber prices increase exponentially in Japan due to various factors such as the fluctuating power of the Japanese yen. As such, the financial cost of fully wooden buildings is an important factor to consider when planning its construction.  

In conclusion, there is sufficient evidence to reason that fully wooden buildings have the potential to impact sustainable construction greatly. Even at a higher cost, comparable buildings made of wood can reduce the carbon footprint of the construction by a significant amount. In the end, it comes down to the execution and the implementation of sustainable construction practices like those from the Obayashi Company to make full use of this technology.  

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Refrence List: Clarke, A. (2023, November 6). Will pure wooden skyscrapers be a game changer for decarbonization, Obayashi's challenge. https://www.bloomberg.co.jp/news/articles/2023-11-06/S3DTNNT0G1KW01 OY Project. (n.d.). Port Plus. (oyproject.com) Obayashi Corporation. (2016). Low-Cost, Long-Span Fire-Resistant Wood Construction Technology: O･Mega Wood (FR). https://www.obayashi.co.jp/chronicle/130th/en/archives/chapter4_1_6.html Kishida, F. (2023). Statement by Prime Minister Fumio Kishida at COP28 World Climate Action Summit. Statement by Prime Minister KISHIDA Fumio at COP28 World Climate Action Summit (Speeches and Statements <br>by the Prime Minister) | Prime Minister's Office of Japan (kantei.go.jp)

Bahrami, A. , Olsson, M. , Svensson, K. (2022). Carbon Dioxide Emissions from Various Structural Frame Materials of Single-Family Houses in Nordic Countries. International Journal of Innovative Research and Scientific Studies, 5(2) 2022, pages: 112-120

Morgan, E (2019, February 26). New Study finds young forests have a huge climate impact. Mongabay Environmental News. https://news.mongabay.com/2019/02/new-study-finds-young-forests-have-a-huge-climate-impact/

Rafferty, J. P. (2023, December 23). Richter scale. Encyclopedia Britannica. https://www.britannica.com/science/Richter-scale

Woodcentral. (2023, November 6). Why Port Plus is the First of a Japanese Timber Building Surge. https://woodcentral.com.au/wood-buildings-grow-in-japan-following-trend-to-decarbonisation/

Building Research Insitute of Japan. (2011). Improving Fire Safety in Buildings. https://www.kenken.go.jp/english/contents/topics/japan-journal/pdf/jj2011aug_09-11.pdf

The Japan News. (2022, July 25). Japanese Lumber Prices Soaring Again. https://asianews.network/japanese-lumber-prices-soaring-again/

Jhariya, M.K., Yadav, D.K., Banerjee, A., Raj, A., Meena, R.S. (2019). Sustainable Forestry Under Changing Climate. In: Jhariya, M., Banerjee, A., Meena, R., Yadav, D. (eds) Sustainable Agriculture, Forest and Environmental Management. Springer, Singapore. https://doi.org/10.1007/978-981-13-6830-1_9