At Expo 2025 Osaka, architect Shigeru Ban has realised the Blue Ocean Dome, a temporary exhibition structure constructed from recyclable cardboard tubes, laminated bamboo, and carbon-fibre reinforced plastic. Designed with modularity, low environmental impact, and reusability in mind, the pavilion demonstrates material strategies relevant to architects, interior designers, product designers, and packaging designers interested in circular design, lightweight structures, and biobased innovation.

Temporary Architecture with a Focus on Sustainability
The Blue Ocean Dome was commissioned by the non-profit organisation Zero Emissions Research and Initiatives (ZERI) and is situated just outside the central Grand Ring of the Expo site. Comprising three interconnected domes—an entrance, a main exhibition hall, and an exit—the pavilion was designed to be lightweight, easily disassembled, and constructed with minimal waste. Each dome utilises a different structural material, selected for its environmental benefits, performance characteristics, and potential for reuse.

Laminated Bamboo: Biobased Structural Innovation
The entrance dome (Dome A) is constructed from laminated bamboo, a processed variant of the natural material that provides improved strength, consistency, and compliance with building regulations. According to Ban, the use of laminated rather than raw bamboo was necessary to meet Japan’s construction standards. Laminating the bamboo enables greater control over structural performance, making it suitable for architectural applications where natural variations would otherwise pose a challenge. The project highlights how engineered biobased materials can be adapted to meet modern performance requirements.

Carbon Fibre: High-Performance Composite for Lightweight Construction
The central dome (Dome B), which houses the main exhibition, is formed using carbon-fibre reinforced plastic tubes. While typically used in aerospace and automotive industries, this material was chosen for its exceptional strength-to-weight ratio, allowing the structure to be built without concrete foundations. According to Ban, the total weight of the dome is less than the soil removed from the site, which eliminated the need for piles and reduced the construction timeline. This application demonstrates how high-performance composites can reduce structural loads and simplify foundation requirements in architectural contexts.

Cardboard Tubes: Recyclable, Modular, and Low-Impact
The exit dome (Dome C) is constructed from recyclable cardboard tubes, arranged in a molecular-like structure. Cardboard has been a signature material in Ban’s work due to its accessibility, recyclability, and ease of assembly. Its use here reinforces the project’s emphasis on temporary construction and material circularity. The lightweight nature of cardboard makes it suitable for demountable structures, particularly where ease of transport and reconfiguration are priorities.

Interior Exhibition: Highlighting Ocean Conservation
The interior of the pavilion features exhibits curated by Kenya Hara, Japanese designer and art director for the brand Muji. The displays focus on the value of the world’s oceans and the environmental challenges they face, including pollution and degradation. The central dome includes a 360-degree film projection, enhancing the visitor experience and linking the pavilion’s material construction to its environmental narrative.

A Case Study in Material Experimentation
The Blue Ocean Dome offers a case study in the use of alternative, sustainable materials in temporary architecture. Through the integration of laminated bamboo, carbon fibre, and cardboard, the pavilion explores the performance potential and environmental implications of each. The project demonstrates how design and material choice can align to promote modularity, reuse, and resource efficiency, offering valuable insights for designers aiming to reduce the environmental footprint of the built environment.

Source: Dezeen
Photography: Hiroyuki Hirai