Kazuyo Sejima Completes Her Most Complex Work So Far

Famous outside of Japan for her work with SANAA, whose rational forms appear implausibly light, Kazuyo Sejima has just completed what she describes as her “most complex shape so far.” Though the apartment building hugs the corners of a 4,900-square-foot lot in the Okurayama neigh­borhood of Yokohama, a suburb of Tokyo, it does not max out the available space. Instead, airy voids perforate the concrete structure, making way for courtyards, terraces, and channels of natural light.

Completed last year for her independent firm, Kazuyo Sejima & Associates, the 52-year-old arch­i­tect’s design refutes the Japanese practice of packing residences within inches of one another and cutting off all but windowless interiors from the world around them. She says that although her fellow architects are often concerned with avoiding such cramped conditions, their solutions do not go far enough. “Architects may think about how to have a good relation with the surroundings but just in terms of one building volume,” Sejima says. “I want to bring character to each of the individual apartments.”

The key distinction at the Okurayama building is the curvature of the internal walls, which Sej­i­ma punctured through in various places on the ground floor to create a courtyard that all residents traverse to enter their apartments. It is an irregularly shaped space, with nooks and crannies that serve as semiprivate gardens for several of the units. And for those apartments that don’t have outdoor gardens, Sejima carved out second- and third-floor terraces. The design manages to grant both privacy and a sense of community. “These are apartments where people can feel more open toward the outside, and where there is at least some kind of com­mun­ication between the residents,” she says. “Instead of being surrounded by a clearly fenced boundary, people should make some effort to claim their own territory.”

Internally, the curved walls give each unit a unique profile and private views. The irregular shapes work because the apartments aren’t subdivided into smaller rooms, but to make furnishing them easier Sejima gave each room two straight walls. For Naoko Kawachi, a resident of the building, the nonlinearity is a space-planning advantage. “Put­ting a table or placing shelves against the curved wall creates angles in the room that are a natural place for having dinner or reading books,” she says, before offering the ultimate endorsement for Sejima’s design. “The curves in the glass make the boundary between the garden and the room ambiguous, so you experience the outside and indoors closely together.”