Buildner's Unbuilt Award 2025 competition participant - Hirotaka Koizumi

We’d like to take the opportunity to introduce you to the participant in our Buildner's Unbuilt Award 2025 competition - Hirotaka Koizumi from Japan!

Hirotaka Koizumi with team

Please tell us about your company (when it was founded, where it is based, how many employees, etc) Alternatively, if you do not have a company, please give us some insights on your own professional/academia background.

Aquattuor Co., Ltd. was established in 2024 with bases in Tokyo and Kinshasa, under the banner of the “four a’s: a-quattuor” — a vision to connect Asia and Africa in a fashionable and meaningful way through architecture, technology, and art. Although the company has a team of four, it maintains a multidisciplinary structure capable of covering architecture and urban design, interior design, facility operation and maintenance, as well as education, training, and programming in architecture and art. Since its founding, the company has pursued a design approach rooted in local issues and cultural contexts, developing cross-border architectural practices primarily across Asia and Africa.

Brief information about the projects that you/your company have been involved with. For instance, what scale have you focused on/preferred, any significant projects where the company/ individuals have been Involved?

Our company specializes in internationally collaborative design and planning, and has been involved in a wide range of projects including educational facilities, public buildings, urban regeneration, and cultural institutions across various scales. Representative examples include the Saudi Arabia Pavilion for Expo 2025 Osaka–Kansai (two-story SRC structure), a new embassy project for a Western European nation in Tokyo (one basement floor and six above-ground floors, SRC structure), a battery power plant project in the Andaman Islands of India (two-story RC structure), community facilities in rural Africa utilizing earth and bamboo (single-story), and the basic design of a university medical school building (six-story SRC structure). With a focus on materials suited to local contexts and sustainable construction methods, we aim to create architecture that generates lasting social value.

What does architecture mean to you and what is the role of an architect in your society?

For us, architecture is a “mediating apparatus” that reveals social issues and enriches human life, serving as a conduit between culture and the future. The role of the architect is not merely to create space, but to integrate a region’s culture, technologies, economy, community voices, and its inherent context—its genius loci—into a coherent proposal that offers new possibilities to society. In an era where diverse values intersect, architects should function as facilitators of dialogue and as professionals who contribute to the creation of sustainable and inclusive environments.

Why do you participate in architecture competitions?

Architecture competitions provide a platform to freely explore new proposals for society, offering an important opportunity to accumulate knowledge and techniques that can inform future projects. They also serve as a valuable process in which architects from different countries, cultures, and generations can share ideas and refine their thinking through dialogue. Within the constraints of everyday practice, competitions allow us to return to the essence of architecture and articulate a vision for society with greater purity. This ability to express unbounded ideas is a major motivation for my continued participation in competitions.

What advice would you give to individuals who struggle to decide whether it would be beneficial for them to participate in architecture competitions?

Architecture competitions offer value not in their outcomes, but in the training of thought and the expansion of perspective, and the experience gained through participation can significantly enrich professional practice. For those who are uncertain, I recommend starting with smaller themes or competitions aligned with their areas of interest, approaching them as opportunities to cultivate one’s own design language. Competitions are one of the most effective ways to reassess one’s position and clarify what one wishes to propose to society. It is important not to seek perfection, but to take the first step with the mindset of learning. In particular, what we deeply appreciated about Buildner’s competitions was the scoring service. The feedback provided through ten assessment criteria made our current standing visible, and this transparency was highly encouraging for our team.