Katsuju philosophy for circular timber use of Saitama’s mature forests

Construction firm AQ Group has affirmed its commitment to advancing a circular economy for timber by supporting the 75th National Arbor Day festival, held in Saitama Prefecture for the first time in 66 years. The company is championing the local government’s philosophy of “katsuju,” a concept that promotes the active utilisation of mature forest resources to ensure their sustainable circulation.

The National Arbor Day is a major annual forestry event, held since 1950 with the attendance of the Emperor. This year’s ceremony took place on May 25 at Chichibu Muse Park. During the event, Saitama Governor Motohiro Ono declared his commitment to the katsuju approach.

“About 80% of Saitama’s artificial forests have reached a usable age, and it is important to promote the circular use of these abundant forest resources and manage them appropriately,” Governor Ono stated in his opening address. “Through this tree-planting festival, we will promote ‘katsuju’, which is the utilisation of forest resources and expansion of wood use, to connect Saitama’s diverse forests to the next generation.”

AQ Group, which recently relocated its headquarters to Saitama, sponsored the event to support its home prefecture and reinforce its role as a wooden construction enterprise. Katsuhiro Kato, President and CEO of AQ Group, participated in the ceremony and planted a tree.

“As a company that deals closely with timber every day, it is our duty to think and act with the environment and circulation in mind,” Kato said. “Our company will participate in the cycle from the perspective of utilising wood.” He affirmed that the company’s business activities are directly linked to the katsuju philosophy.

Japan’s forests, which cover approximately two-thirds of the nation’s land, are entering a new phase. With many post-war plantations now mature, the focus is shifting from planting and nurturing to a complete cycle of planting, growing, felling, and using. This correct circulation is vital for disaster prevention, ecosystem preservation, and climate change mitigation.

AQ Group is putting this principle into practice through its diverse wooden construction projects. The company’s portfolio includes its eight-story, purely wooden head office building and a five-story wooden model house, which utilise 36% and 43% domestic timber, respectively. Its new wooden apartment series, “AQ FOREST,” has committed to using over 50% domestic timber in all buildings.

The company also gained international attention for its “planed wood straws,” an initiative born from the 2018 West Japan floods to find effective uses for thinned wood from forest management. The straws were showcased at the G20 Osaka and G7 Hiroshima summits and were adopted as souvenirs at the Japan Pavilion of the Dubai Expo.

While awareness initiatives like its “Mokuiku Fes” wood education events are important, AQ Group believes its greatest contribution to the environment is the popularisation of wooden buildings. In October 2023, the company launched “Forest Builders,” a consortium of regional construction firms and contractors, to accelerate the adoption of wooden architecture across Japan. Through these efforts, AQ Group continues to promote the sustainable use of forest resources, contributing to a circular and decarbonised society.