OFFICE IN SEGI PARK

At Seki Park, a circular fishing pond operated until June 2021, after which declining use and aging facilities prompted a renewal of the park and its management building. To ensure security and children’s safety, the office was enclosed by a fence and a clear management route was defined from the street, giving rise to the question of how to open the site while accommodating its “back.” Public projects awarded through competitive bidding often result in safe, restrained designs. Yet for a park, we hoped for greater expressive range. Seeking a space that citizens could cherish over time—abstract yet tactile—we explored many proposals, and with the client’s understanding, ultimately arrived at the most daring scheme.

This single-story, 200-square-meter building houses a park management office, public restrooms, storage, and a covered plaza for children to play in rain or strong sunlight. With the required rooms occupying only a small portion, the building takes the form of a large pavilion embracing the open plaza. The triangular plan assigns each corner a role—office, restroom entrance porch, and bench—creating moments of circulation and pause.

Although the original brief called for reinforced concrete, timber construction was chosen in response to the limited budget and the park’s child-friendly context. What appears unconventional is in fact a simple equilateral triangle, 21 meters on each side, based on a 3-meter module. The large triangular roof is stably supported by tripod-like load-bearing walls, and a truss system allows for slender members and fewer piloti columns. Behind its playful appearance lies a sound structural logic.

The ceilings and soffits are left exposed in structural plywood, allowing the structure itself to define the space while keeping costs low. Although the hexagonal office may seem impractical, entrances, windows, storage, wet areas, and desks fit naturally without functional compromise. Rounded columns ensure safety for children. The storage room, accessible from both inside and outside, is finished in exposed plywood and retains flexibility for future updates.

The park sits at a junction between the “river-like” Nishisansō Yutori Path to the north and the “sea” of Tsurumi Ryokuchi to the south, holding the potential to become an “urban brackish zone” where people naturally mingle. With the circular fishing pond—the former center—filled in, the architecture was required to assume a new center of gravity. The equilateral triangle thus emerges as a form embodying that new core.

This place was planned with the safety of children as a priority and is now used daily, primarily by children from the neighborhood. While children were placed at the center of its use, the space was designed to remain generously open to everyone. Like new growth taking root, we hope that a diversity of activities will naturally emerge from here.