Every arch at Tama Art University Library is 200 millimetres thick, whether it spans 1.8 metres or 16, and Toyo Ito lays them along crossing curves just inside the main gate of a campus in the suburbs of Tokyo.
The first question was about the campus, not about books. At Tama Art University in Hachioji, the cafeteria was the only place that students and staff from every discipline shared, so Toyo Ito & Associates began by asking whether a building with a single specialist purpose could belong to everyone. The plot climbs a slight incline behind a garden of trees big and small; the library stands two storeys over a basement, 5,639 square metres in all.
The answer starts at ground level: a wide open gallery meant, in the office's words, as "an active thoroughfare for people crossing the campus, even without intending to go to the library." Its floor keeps the slope, which Ito, in a 2006 lecture, gave as 1 in 20, the same as the site. Exhibitions and events use the gallery, a theatre area has a big screen, and at the back, students waiting for the bus can watch films at a counter set up like a bar or leaf through current magazines on a big glass table.
The arches serve the same wish, placed at random so that people and views pass straight through and the garden seems to continue inside. Each is steel plate encased in concrete, set on curved lines that cross in plan. The crossings let the arches stay extremely slender at the foot under the heavy floor above, and no two column feet share a shape. Mutsuro Sasaki of Sasaki Structural Consultants engineered the frame, which sits on base isolation. In giving the building an award, the Japan Society of Seismic Isolation credited that system with letting a library, with all the weight the word implies, stand on legs as pinched as high heels.
Ito said in the same lecture that curving everything would have been easy in concrete alone. The office insisted instead on curved glass between the arches, set flush. Walk through arches of different span and height and the sequence, as the office puts it, "changes seamlessly from a cloister-like space filled with natural light, to the impression of a tunnel that cannot be penetrated visually."
Upstairs the floor turns level. Large art books sit on low shelves that cross under the arches, with study desks of various sizes between them; the university counts about 100,000 books on the open stacks, with closed stacks behind glass. Where rows of arches intersect they mark out soft zones within one room, each with its own character from shelves and desks of different shapes and glass partitions that double as bulletin boards.
None of this was the first idea. Ito's lecture traces the path from a scheme that buried the entire library beneath a sculpture garden, through cave-like hollows and Wright-style mushroom columns, to the field of arches completed in February 2007. The office likens a walk through it to a forest or a cave. The cave never went underground. It came up into the light, and the campus walks through it.
