Interview
Pooling Technical Expertise to Turn Standard-Dimensional Constraints into Design
A "Tree Stump" Pavilion Built with Temporary Site Materials
In preparation for exhibiting at GREEN×EXPO 2027, what challenges did the OBAYASHI MORI SORA MIRAI project team face, and how did they act? This second installment of our series―revealing the process through interviews with the people responsible―features four individuals involved in architectural design, structural design, electrical, and mechanical engineering.
How did the exhibition concept "New Sustainable Life with MAKE BEYOND" and the future-oriented message "Embrace Nature, Embrace Happiness" discussed in Episode 01 translate into the final design and structure?
How did the exhibition concept "New Sustainable Life with MAKE BEYOND" and the future-oriented message "Embrace Nature, Embrace Happiness" discussed in Episode 01 translate into the final design and structure?
Profile
OBAYASHI CORPORATION
Assistant Manager
Architectural Design Solutions Department
Marco Capitanio
Born in Italy. After working in architectural design overseas, he came to Japan and joined the company in 2021. At OBAYASHI MORI SORA MIRAI, he is responsible for architectural design, focusing on the spatial composition of exterior structures and entrance areas. In his day-to-day work, he uses computational design to automatically generate designs and simulations, working on tasks such as design optimization and 3D-printed architecture projects.
OBAYASHI CORPORATION
Manager
Structural Engineering Department
Shotaro Murata
Joined the company in 2010. At OBAYASHI MORI SORA MIRAI, he is responsible for overall structural planning. During the internal design competition for the pavilion, he collaborated with Hiroki Minoura from the Architectural Design Department, who appeared in Episode 01. He also felt a connection to the project because he lives in Yokohama City, the host city for GREEN×EXPO 2027. He is primarily engaged in structural design for office buildings, arenas, and similar structures.
OBAYASHI CORPORATION
Expert
Mechanical & Electrical Engineering Department
Yuki Hatanaka
Joined the company in 2010. He is responsible for overall electrical equipment planning for OBAYASHI MORI SORA MIRAI. He designs power supplies for key operational systems—show lighting and air-conditioning equipment—and is also involved in exterior lighting design that contributes to the pavilion’s nighttime illumination. He also frequently handles building services design for logistics warehouses.
OBAYASHI CORPORATION
Mechanical & Electrical Engineering Department
Ken Yasuda
Joined the company in 2024. He joined this project in his second year at the company. This is the first project for which OBAYASHI MORI SORA MIRAI has handled design work. He is involved in creating comfortable environments through planning HVAC systems and plumbing/sanitary facilities, as well as selecting equipment.
Index
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For the Six-Month Exhibition Period, in Line with Sustainability
Construction-Site "Temporary Materials" Adopted as Building Materials for the Pavilion
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Achieving a Sense of Accomplishment by Fulfilling Challenging Orders
Pay Attention to the Technological Capabilities of the Obayashi Group
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Still Room for Improvement
Creating for the Next Stage
For the Six-Month Exhibition Period, in Line with Sustainability
Construction-Site "Temporary Materials" Adopted as Building Materials for the Pavilion
Marco
In March 2025, my proposal was selected as "Gold" in the company's internal design competition for the pavilion, following Minoura's "Platinum" proposal, and I joined this project. I was surprised when I received the notification, but above all, I was proud to be involved in such a high-profile project. When I visited the Milan International Exposition in 2015, I felt a strong emphasis on "green" throughout the venue, in addition to the main theme of "food." Now, almost 10 years later, I feel a sense of destiny in being involved in the work for GREEN×EXPO 2027.
Taking Minoura's idea, we created a landscape design based on the motif of a "tree stump" that gives off a half-natural, half-artificial atmosphere. The tree stump represents Obayashi Corporation as an "Explorer" that will pioneer the future.
While decision-making took time due to the involvement of diverse stakeholders and employees, the design exploration process offered many valuable lessons. Additionally, as an internal project, we were able to try out new software and workflows, and being able to validate their effectiveness was a major takeaway.
Taking Minoura's idea, we created a landscape design based on the motif of a "tree stump" that gives off a half-natural, half-artificial atmosphere. The tree stump represents Obayashi Corporation as an "Explorer" that will pioneer the future.
While decision-making took time due to the involvement of diverse stakeholders and employees, the design exploration process offered many valuable lessons. Additionally, as an internal project, we were able to try out new software and workflows, and being able to validate their effectiveness was a major takeaway.
Exterior rendering of OBAYASHI MORI SORA MIRAI, composed of multiple cylindrical buildings linked in a series, inspired by the motif of a "tree stump."
Murata
The complex consists of multiple cylindrical buildings. The size and height of each building were defined based on the purpose of the exhibition space and the shape of the displayed objects. However, discussions frequently arose about whether the exterior view from the approach path was aesthetically pleasing or seemed unnatural. In such moments, it was incredibly helpful that Marco frequently visualized the design for us using 3D software. Visualizing not just the building, but also the types of plantings and even nighttime lighting simulations in detail made it easier for the team to share a common vision and helped us reach consensus faster.
Marco
Thank you. In designing OBAYASHI MORI SORA MIRAI, our initial focus was to create something that both concretely expresses the exhibition theme and delivers impact. We envisioned an exterior and entrance that would spark visitors' intellectual curiosity when they arrive and see the entire landscape, making them wonder, "What kind of experience can I have here?" We also prioritized designing the transitional spaces connecting the buildings and working closely with landscape designers to visualize and refine every detail of the greenery.
Murata
In structural planning, I considered that the building's operational period is limited to about six months, and since it's a pavilion for GREEN×EXPO 2027―deeply linked to sustainability―we couldn't use materials or construction methods typically adopted for permanent structures. Therefore, adhering to the exhibition concept "New Sustainable Life with MAKE BEYOND" and Obayashi Corporation's future-oriented message "Embrace Nature, Embrace Happiness," once the decision was made to adopt a cylindrical form resembling a tree stump, we explored using temporary (leased) site materials as much as possible.
Specifically, we arranged leased scaffolding materials (Albatross (*1)) around the outer perimeter of the buildings as exterior support members, and inside, we built a structural frame using shoring materials (yamadome) (*2) together with Albatross beam frames, creating a building compliant with the Building Standards Act. Additionally, we adopted Lamina panels (wood-based panels) for the exterior cladding, considering their contribution to carbon neutrality. Furthermore, by employing a structural framing system (*3) using compression rings (*4) and tension rods (*5), we created a distinctive structural design. Each component was assigned to the most suitable location to maximize its strengths, thereby constructing the exhibition space.
Specifically, we arranged leased scaffolding materials (Albatross (*1)) around the outer perimeter of the buildings as exterior support members, and inside, we built a structural frame using shoring materials (yamadome) (*2) together with Albatross beam frames, creating a building compliant with the Building Standards Act. Additionally, we adopted Lamina panels (wood-based panels) for the exterior cladding, considering their contribution to carbon neutrality. Furthermore, by employing a structural framing system (*3) using compression rings (*4) and tension rods (*5), we created a distinctive structural design. Each component was assigned to the most suitable location to maximize its strengths, thereby constructing the exhibition space.
- *1Albatross
A temporary work platform erected at high elevations on construction sites to enable workers to move and work safely. Widely used as next-generation scaffolding that balances enhanced safety with improved work efficiency. - *2Shoring materials (yamadome)
Temporary steel supports used to reinforce retaining walls, preventing soil collapse and ground subsidence during deep excavation. - *3 Structural framing system
A structure that supports a building's load by combining columns, beams, and other elements to form a framework. - *4Compression Ring
A ring-shaped reinforcement member installed at the central opening or apex of shell-structured roofs, such as those in domed baseball stadiums. - *5Tension Rod
A structural member that resists forces by "pulling" to support the building.
Achieving a Sense of Accomplishment by Fulfilling Challenging Orders
Pay Attention to the Technological Capabilities of the Obayashi Group
Hatanaka
I joined this project in March 2025, the same time as Marco. At that point, we were building on Minoura's proposal and conducting further discussions within the Architectural Design & Engineering Division to integrate the plans. However, since it was right before the Expo 2025 Osaka, Kansai, Japan, our focus was almost entirely there. My initial reaction was something like, "Horticultural Expo? Are we building a garden or something?" (laughs). Then, when I heard the building would be constructed using temporary scaffolding and shoring materials to mimic tree stumps, my honest reaction was, "I've never worked on electrical systems for a building shaped like that." While it's great that our own pavilion offers such high design freedom, it also means challenging cross-departmental coordination and sometimes unreasonable demands. Still, unlike typical projects, the fun of creating something together with colleagues across the Architectural Design & Engineering Division far outweighs any difficulties.
Marco
What specific aspects did you find particularly interesting?
Hatanaka
What I found both interesting and challenging was the request to "make the various temporary materials composing the exhibition space look like they aren't temporary materials." We struggled with how to expose temporary lighting used to brighten construction sites for lighting exhibits in some places, while carefully concealing it in others to avoid distracting from the building. In addition, ensuring visitor safety at night required balancing these elements, which was difficult. And to begin with, placing electrical equipment inside the Albatross was something I never imagined—"Seriously?!" The exterior Lamina panels also have a polygonal configuration that creates gaps at the corners. This meant the building's water-stop line shifted to the interior wall side, necessitating waterproofing specifications for equipment located between the exterior cladding and interior walls, among other countermeasures. As we refined the design, challenges emerged one after another, making it quite demanding. However, we're clearing each hurdle and the project is taking shape.
Yasuda
As Hatanaka mentioned, while concealing equipment is certainly necessary, I also believe this project presents an excellent opportunity to showcase the Obayashi Group's technical capabilities to the world. Regarding the mechanical equipment, I want visitors to truly experience the technologies the Obayashi Group has helped develop.
First is the outdoor installation of "Comfy TOUCH" (*6). This incorporates cold/hot water panels into benches, creating "ultra-localized heating and cooling" that utilizes heat conduction and radiant heat. Visitors can directly touch the panels to feel a cooling sensation, enabling localized, highly energy-efficient, and effective heat countermeasures.
The second is the "in-DUCT" air outlet type (*6) for installation in exhibition rooms. This technology integrates the air intake mechanism with the air outlet, drawing in surrounding air to increase the airflow volume. This allows the air conditioner itself to reduce its airflow volume, lowering fan power consumption. It achieves reductions in power consumption and CO2 emissions, while also suppressing condensation.
Finally, the "Saratto Mist" (*6) is installed outdoors. By spraying a fine mist that doesn't feel wet upon contact, it generates evaporative cooling, lowering the surrounding air temperature by 2-3 °C to create a comfortable environment.
This technology is incorporated into "The brænch" (*6), a structure made with a metal 3D printer at the Obayashi Corporation Technology Research Institute―a project in which Marco is also involved. I believe this structure truly symbolizes the fusion of technologies within the Obayashi Group.
First is the outdoor installation of "Comfy TOUCH" (*6). This incorporates cold/hot water panels into benches, creating "ultra-localized heating and cooling" that utilizes heat conduction and radiant heat. Visitors can directly touch the panels to feel a cooling sensation, enabling localized, highly energy-efficient, and effective heat countermeasures.
The second is the "in-DUCT" air outlet type (*6) for installation in exhibition rooms. This technology integrates the air intake mechanism with the air outlet, drawing in surrounding air to increase the airflow volume. This allows the air conditioner itself to reduce its airflow volume, lowering fan power consumption. It achieves reductions in power consumption and CO2 emissions, while also suppressing condensation.
Finally, the "Saratto Mist" (*6) is installed outdoors. By spraying a fine mist that doesn't feel wet upon contact, it generates evaporative cooling, lowering the surrounding air temperature by 2-3 °C to create a comfortable environment.
This technology is incorporated into "The brænch" (*6), a structure made with a metal 3D printer at the Obayashi Corporation Technology Research Institute―a project in which Marco is also involved. I believe this structure truly symbolizes the fusion of technologies within the Obayashi Group.
- *6Links available only in Japanese
Marco
For this design project, I wanted to introduce designs that deliver a physical impact and symbolically express the exhibition theme. The brænch is precisely one such element. While the overall landscape is important, I also hope many visitors will see, touch, and experience The brænch, which I designed.
Still Room for Improvement
Creating for the Next Stage
Hatanaka
With less than a year remaining until GREEN×EXPO 2027, where Obayashi Corporation will exhibit, what aspects do you particularly want visitors to see, Marco?
Marco
The areas I especially want people to see are the entrance approach and the distinctive equipment we deliberately chose to showcase. While actively using temporary materials commonly found on construction sites, I hope visitors will sense that this is a special pavilion that balances aesthetic appeal with ease of dismantling.
Hatanaka
Indeed, as Marco mentioned, I hope visitors will pay close attention to how we've balanced the seemingly contradictory concept of "concealing while revealing." I also hope they enjoy the night view with the stump-shaped buildings illuminated.
Murata
The exterior Lamina panels mentioned earlier by Hatanaka are configured with a base unit of 2 m or 3 m in height and 50 cm in width, matching the temporary fencing at construction sites. Furthermore, the pavilion constructed using Albatross scaffolding materials faced certain constraints on height and diameter due to the dimensional specifications of the Albatross modules. We hope you’ll see how this design achieves its ideal aesthetic while enabling rational construction even under such conditions.
Looking ahead, there are plans to deploy these Lamina panels as wood-based temporary fencing panels at Obayashi’s construction sites in the future. The evaluation from this project could serve as an important test case for that initiative. In that sense, we also hope you will pay close attention to the exterior design.
Looking ahead, there are plans to deploy these Lamina panels as wood-based temporary fencing panels at Obayashi’s construction sites in the future. The evaluation from this project could serve as an important test case for that initiative. In that sense, we also hope you will pay close attention to the exterior design.
Yasuda
While the facilities are not meant to be the main attraction, we hope that as you experience OBAYASHI MORI SORA MIRAI, you will sense the comfortable spaces created to complement the exhibits and presentations.
Furthermore, regarding the Obayashi Group's technologies I mentioned earlier, their appeal truly comes through when you "experience them firsthand". We would be delighted if experiencing them on-site sparked even a little interest.
Furthermore, regarding the Obayashi Group's technologies I mentioned earlier, their appeal truly comes through when you "experience them firsthand". We would be delighted if experiencing them on-site sparked even a little interest.
Murata
OBAYASHI MORI SORA MIRAI is still in a state where we are all "nurturing" it together, and it can be said there is still room for upgrades to create an even better pavilion. Let's continue refining it as much as possible and move forward to the next phase.
The departments and job titles shown are current as of April 2026.
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