With advantages in cost, construction time, and compliance with sustainability standards, the application of engineered wood in architectural projects is steadily expanding.
The World Expo 2025 in Osaka, Japan, held from April 13 to October 13, marks an important turning point in the trend of using wood for large-scale structures.
From the world’s largest wooden architectural symbol
The Grand Ring—a massive wooden structure designed by architect Sou Fujimoto—has been recognized by the Guinness World Records as the largest wooden architectural structure in the world.
Resembling a circular enclosure at the center of the exhibition grounds, the Grand Ring spans 30 meters in width and about 675 meters in outer diameter. It uses 20,000 m² of timber, including cedarwood from Fukushima Prefecture, cypress from Shikoku Island, and some Scottish pine. What makes the structure unique is its use of the traditional Japanese joinery technique called “nuki koho”—a method of interlocking wood without nails or screws, often found in ancient temples and shrines in Japan.
Alongside the Grand Ring, Expo 2025 also highlights the choice of wood as the primary construction material for many national pavilions. Among them: Austria’s pavilion, with a spiral structure inspired by a musical staff, built entirely from wood; Germany’s pavilion, showcasing rounded timber structures; Hungary’s pavilion, featuring a wooden and paper exterior with a timber dome; and the host country Japan’s pavilion, constructed with cross-laminated timber (CLT) in a belt-like form.
Towards a global trend
Prior to the Grand Ring, Tavico’s wooden dome at the Hung Kings Commemoration in 2023 also drew attention. Covering more than 1,100 m², the structure was completed in just 21 days. This remarkable construction speed was achieved thanks to pre-fabricated modular systems. Square wooden beams were assembled in a lattice structure, creating an impressive visual effect for the entire project.
By Hanh Nguyen – Gỗ & Nội Thất Magazine
