Making Use of Japan-grown Timber to Promote Sustainable Use of Forest Resources
- Promoting Utilization of CLT to Further Expand Use of Japan-grown Timber
- Developing Japan's First High-Rise Concrete-Wood Hybrid Hotel Using Hokkaido-Grown Timber
- PARK WOOD Office Iwamotocho — an 8-story Office Building Built with CLT
- PARK WOOD Takamori — Rental Apartments in Izumi-ku, Sendai City
- Miyako Shimojishima Airport Terminal
Promoting Utilization of CLT to Further Expand Use of
CLT material image (courtesy of the Japan Cross Laminated Timber Association)
Japan's forests account for some two-thirds of the country's land mass, with their 40% being planted forests. Many such forests were planted after World War II, and today more than half of these planted forests are five decades old or more, having reached their harvestable age. Expanding the use of timber sourced from these forests not only helps promote Japanese forestry, but is also thought to contribute to the preservation of Japan's natural forests. Based on this perception, the Mitsubishi Estate Group has set out a goal to promote sustainable timber use under the key theme of Environment in the Mitsubishi Estate Group 2030 Goals for SDGs and is promoting the utilization of Japan-grown timber and certified timber.
The Mitsubishi Estate Group has promoted the use of Japan-grown timber in construction projects for many years, including the active use of small-diameter trees and timber from forest thinning in 2×4 wooden-frame houses. In recent years, the Group has also been focusing efforts on expanding the use of cross laminated timber (CLT).
CLT consists of large-dimension wooden panels formed by laminating layers of sawn lumber perpendicular to one another. Compared with conventional wooden panels, its strength is more stable, and it also offers outstanding heat insulation. It is gaining attention as a construction material that will expand the applications of timber since it can be used not only for low-rise detached housing, but also for large-scale structures such as condominiums and office buildings.
Mitsubishi Estate formed the CLT Wood Promotion Unit, a dedicated department in fiscal 2017. The unit is working on research and development aimed at commercialization of CLT and has already implemented several projects. In order to further accelerate the initiative, Mitsubishi Estate established MEC Industry Co., Ltd. in January 2020 and began building a plant for timber processing in Yusui Town, Kagoshima Prefecture. The company engages in the production, processing, manufacturing, assembly, and sale of timber building materials, primarily 2×4s and CLT. In addition, the use of timber grown in Kagoshima, Miyazaki, and Kumamoto prefectures on the production line is believed to contribute to the goal of promoting sustainable timber use.
Developing Japan's First High-Rise Concrete-Wood Hybrid Hotel Using Hokkaido-Grown Timber
A lounge furnished with Hokkaido-grown timber (artist's rendering)
Mitsubishi Estate is debuting The Royal Park Canvas – Sapporo Odori Park, Japan's first high-rise hybrid hotel built of reinforced-concrete and wood using Hokkaido-grown timber, on October 1, 2021. Located in Sapporo, Hokkaido, the hotel will be operated by Royal Park Hotels and Resorts. The property features a hybrid wood building with the lower and middle floors constructed from reinforced-concrete with wooden ceilings; one floor in the mid-rise section built with a hybrid reinforced-concrete and wooden structure; and the upper floors constructed using an entirely wood-built structure. The property brings together all the advances in wood construction made by the Mitsubishi Estate Group to date.
Approximately 80% of the wood used as a structural material is Hokkaido-grown timber. The use of Sakhalin fir, which is the most abundant resource in any of Hokkaido's plantations, in various parts of the building, including the CLT flooring, contributes to promoting local industry and recycling forest resources. The interior designs of the hotel's guest rooms and lobby also make extensive use of timber, capitalizing on the local characteristics of Hokkaido. The project was selected for inclusion by the Ministry of Land, Infrastructure, Transport and Tourism in the Fiscal 2019 2nd Pilot Projects for Sustainable Buildings (Wooden Structure).
See the press release dated March 26, 2020 for more details.
PARK WOOD Office Iwamotocho —
an 8-story Office Building Built with CLT
PARK WOOD Office Iwamotocho
PARK WOOD Office Iwamotocho, an 8-story office building using CLT as a structural material, was completed in March 2020. It is Japan's first office building over six stories to use CLT as a structural material and is also the Mitsubishi Estate Group's first office building to use CLT.
The building was selected for inclusion in the Ministry of Land, Infrastructure, Transport and Tourism's Fiscal 2018 Pilot Projects for Sustainable Buildings (Wooden Structure) and has attracted attention as a model for a high-rise non-residential building using CLT in a built-up area.
Incorporating knowledge gained from achievements in PARK WOOD Takamori, a previous rental apartment project, such as the installation of fire-proof floors, the completed office building delivers the warm feel of wood.
PARK WOOD Takamori —
Rental Apartments in Izumi-ku, Sendai City
PARK WOOD Takamori
PARK WOOD Takamori, a 10-storey apartment complex completed in Sendai City in February 2019, is Japan's first-ever high-rise building using CLT as a flooring material. From the design stage onward, features such as fire resistance, sound proofing, and earthquake resistance were repeatedly verified to realize a hybrid wood and steel-frame structure through the use of fireproof coatings and other materials.
This project has helped to amass the processes and know-how in design and construction required for building using CLT, thus allowing the Mitsubishi Estate Group to utilize CLT in other projects going forward.
Miyako Shimojishima Airport Terminal
Check in lobby using CLT as structural material for the roof
Miyako Shimojishima Airport Terminal opened in March 2019 on Miyako Island, Okinawa, where there is abundant nature. It is the first airport terminal in Japan to utilize CLT as a structural material for the roof. The CLT was produced with regional wood designated by Okinawa Prefecture, thereby contributing to the vitalization of the regional forestry industry. The project has also implemented a range of energy-saving measures and earned the Net Zero Energy Building (ZEB) recognition, the first for airport terminals in Japan.