Lord of the Ring: Sou Fujimoto’s Mass Timber Vision

Sou Fujimoto’s circular mass timber pavilion at Expo 2025 reimagines architecture as both structure and ecosystem, sparking debate on design and sustainability.

Sou Fujimoto’s newest project for Expo 2025 in Osaka isn’t only about spectacle it’s a signal of where architecture is heading worldwide. Fujimoto, famous for blending nature with built form, has sketched out a huge circular timber pavilion at once welcoming and a little uncanny. Its looping shape and hollow center push visitors to see architecture less as a fixed object and more as something alive, reacting to its setting. It isn’t only a world’s fair attraction it’s proof that timber, one of the oldest materials around, can be reinvented for modern cities.

The use of mass timber is no accident it reflects how architects are wrestling with two big forces: sustainability and rapid urban growth. Wood buildings lock in carbon instead of releasing it, making them a natural foil to concrete and steel materials that pump out close to 15% of the world’s emissions. By sheer size alone, Fujimoto’s pavilion shows timber can handle the load of a massive public space and still hold its own. That scale sparks bigger questions for architects and city planners: could timber really serve as the backbone for tomorrow’s megacities? And will building codes in Europe, Asia, and the U.S. move fast enough to match the experiments on show in Osaka?

But the “Lord of the Ring” isn’t just about structure it’s a reminder that architecture today is judged not only on function, but also on how it connects emotionally and culturally in an age of climate pressure. With a design that feels both communal and strangely unfamiliar, Fujimoto pushes us to ask not just how our buildings work, but how they make us feel. For U.S. architects watching Expo 2025 from a distance, the pavilion isn’t just a showpiece it’s a provocation. It hints that tomorrow’s architecture won’t just chase height or spectacle it will be circular, sustainable, and rooted in the very materials that shape our cities.