Koenji Office Building
Emergent Connections and Expanded Roles of Concrete
This headquarters building is situated on a flagpole-shaped lot near Koenji Station, with a frontage of just 2 meters. The building comprises three above-ground stories and one basement level. We sought to free the design from the constraints imposed by the conventional rationality of reinforced concrete structure frames with shear walls, and to expand the roles of concrete. Rather than being constrained by the structural system, we responded to a three-dimensionally fragmented spatial condition by limiting the dimensions of columns and walls to 300 mm or less and defining only the minimum clearance beneath the beams. Within these parameters, the minimum number of columns and shear walls were positioned while ensuring the required structural and spatial dimensions.
Through continuous adjustments to beam widths, beam depths, and the addition, removal, or relocation of columns and beams, numerous beams with varying cross-sections came to be interconnected, each playing its own role: Cantilever beams supporting the H-steel beams of the staircase, intermediate beams that prevent columns from buckling, reduce slenderness ratios, and alleviate structural stresses, as well as a transfer beam resulting from the floor plan of the lower level.
The accumulation of diverse and somewhat fortuitous connections, as well as the 300 mm square concrete elements, gave this building, and the concrete itself, a multifaceted meaning.
Even after the drywall, steel window frames, and steel staircase are removed, leaving only the concrete behind, we hope this building will continue to serve as a bridge to the future.
This office building is owned by a company that has long maintained its headquarters and retail stores in Koenji, where it develops and sells a wide variety of products, including action figures, balance bikes, apparel, and accessories. As a base for this creative and evolving business, we have created a “place of beginnings” that is open to the city and responsive to future changes, rather than a rigid, homogeneous space.
