Sendai Mediatheque

Sendai held an open international competition in 1995 for a building combining a public library with galleries and a media-literacy centre, and the brief itself asked entrants to rethink the conventional layered floor plate. Ito's winning idea removed the columns. Thirteen irregular tubes, welded lattices of thin steel rod bundled tighter where they carry more load, rise through all seven floors like kelp stems, doubling as risers for stairs, lifts, ducts and light; the floor slabs are thin steel-and-concrete decks threaded onto the tubes, and the outer wall is glass from top to bottom with no structural frame of its own. Ito had been developing the tube idea for years without a client able to build it; Sendai's competition brief happened to want exactly that kind of structural transparency. The building withstood the March 2011 Tōhoku earthquake with only cosmetic damage — ceiling panels and glazing gaskets — and reopened within a year, cited afterward as evidence the tube structure had worked as intended.