At first glance, Shibaura House appears as a tall, rectangular, white box. A closer look reveals three large terraces of different sizes and footprints, masked by stretch metal mesh. These volumes seem to be cut into the orderly outer structure. Diagonal beams keep the construction in place and form enormous, slightly puzzling K’s in a façade divided into a shifting pattern of rectangles. Glass panes screen the rest of the building, resulting in the reflecting semi-transparency of the exterior.
The rectangular outer contour disguises the fact that the building consists of a pile of concrete decks of various shapes. A section of the house demonstrates its spatial diversity, attested to by the varying ceiling heights. Each level seems to overlap the next, causing a sensation of flow between the floors. Curving staircases coyly emphasize this feeling.
The south-facing double-high first floor space is publically accessible from the street. It contains tables for working or reading and a coffee station. Plenty of lush green plants provide for a homely atmosphere. The second and third floors are lounge areas appropriable for various purposes such as meetings and cultural events and with access to two terraces. Rounded glass walls divide the spaces into smaller sections. Offices are on the fourth floor, while the corner ‘Bird Room’ on the fifth floor has a commanding view of the surrounding neighborhood. Its 90m2 have no partition walls in order to secure maximum functional flexibility.
Shibaura House is framed and structured by ten loadbearing posts around the façades, resulting in a square 14x14m footprint dividable into nine equal squares. Hence the building may be interpreted as a response to the famous nine-square grid exercise: This exercise was invented by architect John Hejduk in the 1950s and subsequently used at schools of architecture worldwide. The question is how to spatially divide a square, subdivided into nine smaller squares? Sejima offers seven elegant solutions: Curvaceous, yet simple.
Name: Shibaura House│Type: Office│Architect: Kazuyo Sejima│Completed: 2011