Constructing a sustainable pavilion using unprecedented building materials

“BOD Professionals” interviews the people who support the BLUE OCEAN DOME behind the scenes. The second instalment is with Tomoya Ishiguro of the 2025 Japan Universal Exposition (Expo Osaka-Kansai) Promotion Office at Daiwa House Industry Co., Ltd. The BLUE OCEAN DOME was designed by Shigeru Ban, a world-renowned architect, and is made up of three domes made of laminated bamboo timber, carbon (CFRP: Carbon Fiber Reinforced Plastics), and paper tubes. Ishiguro, who has devoted himself to realizing this unique pavilion architecture, spoke about the challenges he faced over the past year and a half and his current thoughts.

Wanting to test the abilities of himself on the challenging stage of the Osaka-Kansai Expo,
he applied for the company’s internal recruitment.

In April 2023, there was an internal recruitment for personnel involved in the Expo Osaka-Kansai project. Until then, I had mainly worked within Kanagawa Prefecture, so I wanted to test my abilities in a new place and improve my skills and broaden my horizons in a big challenging place like the Expo, so I applied. I was successfully accepted, and I was assigned to work alone on August 1, 2023. From then, I worked energetically every day with about 15 members for about a year and a half until the handover in March 2025. While there are many schemes in which Daiwa House is responsible for both design and construction, I was in charge of constructing a pavilion designed by a world-famous architect. Until now, I have been involved in architecture that is meant to be used for a long time, which is the concept of Daiwa House, but this time, the big difference is that it is a temporary structure that will only be used for about half a year during the Expo.

Using unprecedented building materials as the structure,
trial and error were undertaken to realize the design of a world-renowned master.

This pavilion is made up of three domes. Dome A is made of laminated bamboo lumber, Dome B is made of carbon (CFRP), and Dome C is made of paper tubes. These are construction materials that have never been used before. This was a first for both Daiwa House and for me, so it was a constant process of trial and error to find a way to build it smoothly.

Dome C in particular has a double structure, with the inner and outer layers spaced 1m apart, so it was difficult to build it safely and efficiently. Initially, it was planned to be built 1.5 months, but it actually took 3 months, as the material was paper and we struggled with the weather. Dome A was also a millimeter-by-millimeter job of arranging bamboo laminated timber, which can only be bent in two dimensions, into an arch shape, and for Dome B, we started by gaining knowledge about carbon, and then we worked on how to bend it and give it strength, and we proceeded with production and construction in the factory almost simultaneously. In order to materialize Mr. Ban’s image, we discussed using mockups, but each piece was designed with great care, so in order to fulfill his wishes, we took safety, cost, and schedule into consideration, and in a positive sense, we looked for compromises as we carried out the construction. I am truly grateful that it was only thanks to the hard work of the craftsmen on site that it was made possible. In areas where walls will not be built, plywood is attached to plastic resin panels, and concrete is used as little as possible, making it a sustainable building that has been designed with dismantling and relocation in mind after the Expo ends.

If you are interested in architecture as well as water exhibits and video content,
this is a must-visit place.

We feel relieved that the handover was completed safely the other day, but the real work has yet to come, so we hope that everyone of ZERI JAPAN can use it comfortably. For visitors, there are many highlights, such as the water exhibit in Dome A and the impactful video content in Dome B, but as this is a pavilion constructed by Daiwa House featuring Mr. Ban’s work, we would definitely recommend it to anyone interested in architecture.

The surrounding area is filled with well-known pavilions such as Bandai Namco (Gundam) and Yoshimoto Kogyo, so you may not be able to imagine what the BLUE OCEAN DOME will be like, but once inside, you will be able to see architecture that exceeds your imagination, so please look forward to it. After the opening, I will be gazing at the dome from a secluded spot under the big roof of the ring, and when I see the smiling faces of the people coming out of Dome C, I felt I will be overcome with emotions that are hard to put into words.