Seattle Central Library

Seattle Central Library solves an old library problem with a ramp. Its nonfiction collection runs as one continuous sequence, the Books Spiral, climbing from the sixth to the ninth floor on shelving that never slopes more than two degrees. The Dewey numbers follow each other without a break, so the classification never has to be split between floors or wings.

From outside, the eleven-storey building looks like a stack of platforms wrapped in a steel net over a glass skin. Rem Koolhaas and Joshua Prince-Ramus of the Office for Metropolitan Architecture designed it with the Seattle firm LMN Architects. OMA had not been invited to compete. Prince-Ramus, a former Seattle resident, heard from his mother one day before the compulsory public meeting, flew in, and the firm won the job.

Like Oodi in Helsinki later, the building keeps the collection high up and gives the lower floors to the public, with a children’s centre, an auditorium and a “Living Room”.

It opened on 23 May 2004, the third central library on the same downtown block, after a Carnegie library of 1906 and its 1960 replacement. Seattle voters paid for it through the Libraries for All bond of 1998. In the first year 2.3 million people came, about 30 per cent of them from outside the city, and use has run at more than double the forecast.

Opinion has never settled. Paul Goldberger called it “the most important new library to be built in a generation”. Lawrence Cheek, who had praised it, came back in 2007 and called that praise a mistake. The layout has since become a research case in how people find their way through complex buildings.