This project involves the construction of a new tenant building located on a corner lot, just off the main street in Omotesando, Tokyo. While the area allows for a three-story building above ground, the client expressed a desire for a “building open to the city.” Taking this into consideration, we decided to construct a steel reinforced concrete (RC) building with one basement and two above-ground floors, intentionally avoiding the maximum possible height.
Typically, when designing a tenant building, the goal is to maximize the building’s floor area, with the upper floors often reduced in size due to height restrictions. However, prioritizing floor area without clear value can sometimes be counterproductive for the overall functionality of the building. After extensive discussions with the client, we aimed to differentiate and clarify the value of the building by adopting an unconventional layout.
One of the project’s key features is a void (atrium) that extends from the corner of the building down to the basement. The previous building on this site gave a cramped impression due to its volume, which was aligned closely with the narrow streets surrounding the intersection. The closed-off feel of the basement and issues with humidity were also challenges with the previous structure.
The void at the corner serves as a buffer, creating a comfortable distance from the surrounding streets and providing vertical circulation between floors. It also functions as a space that brings light and outside air to the basement. At the same time, the outer perimeter of the building, framed by two structural slabs, creates an invisible façade while allowing visibility to the surrounding area. While this design sacrifices the maximum possible floor area, it results in a more open and elevated space, with higher ceilings (nearly 4 meters) and large terraces on the basement and second floors, offering a sense of openness despite being in a densely built urban area.
Additionally, a single steel round column supports the slab at the corner of the building, maintaining a sense of openness. We also designed custom uplighting integrated with the column to illuminate the void, using reflected light from the ceiling instead of typical downlighting. This approach enhances both the structural and lighting features of the building. Furthermore, the façade design changes the position of the windows on each floor, ensuring the walls accommodate tenant needs while presenting an equal visual impact from all angles.
Though the overall structure is a simple RC construction, careful consideration of the building’s relationship with its surroundings and the perspective from the street has resulted in an architecture that balances functionality with openness, harmonizing with the backstreets of Omotesando.
Type of Project: Newly build
Use: Building for rent
Period: Dec 2021 – Aug 2024
Structure: steel reinforced concrete structure (partially steel-framed)
Scale: 2F/B1
Site area: 177.85m2
Building Area: 108.12m2
Floor Area: 283.54m2
Location: Tokyo, Japan
Building Owner: TENORAS Co.,Ltd.
Project Planning, Building Management: Masayuki Nishimoto, Shiori Yaga (en one tokyo Inc.)
Architecture Design: Koichi Futatsumata, Aki Hashizume (CASE-REAL), Junichi Watanabe (Junichi Watanabe Architects Inc.)
Contraction: SHIN Co.,Ltd.
Structural Engineer: Hirofumi Ohno, Kokuno Naoki (Ohno Japan)
Lighting Plan: Tatsuki Nakamura (BRANCH LIGHTING DESIGN)
Planting Plan: Yuko Takaura(GREENETTA)
Photo: Daisuke Shima