How do you renovate a 430,000 square foot building С most of it underground С without disrupting the essential services it provides to faculty, students, scholars, and others almost every day of the year?

Answer: very slowly.

“This is a saga, not a story,” observed Princeton University Librarian Karin Trainer describing the current renovation of Firestone Library, the largest building on campus. The project is scheduled to be completed in 2018. Until then, a team of architects, from both within and outside the University, meets frequently to share plans and sketches of the day. There are often “multiple screens going at the same time,” said Ms. Trainer. The estimated cost of the project is “in the nine figures,” and is being underwritten by the University, “just as they would a new laboratory for scientists.”

It’s very clear to anyone entering Firestone that a renovation is in progress; scaffoldings and drop cloths abound, and there’s a considerable amount of rerouting to various services. There should be no real sense of dislocation, however, thanks to “a promise to ourselves that we would continue to offer all of the normal services we provide; that the library would stay open its regular hours; and we would not dislodge large portions of collection,” said Ms. Trainer. “We’re moving people and books around to keep them out of the contractors’ way; that’s another reason it’s going to take a long time.”

Built in 1948, Firestone Library was the University’s first major academic building constructed after World II. (The vastness of its underground portion occurred out of a desire not to overshadow nearby buildings, including the Chapel.) “The University has maintained it very carefully over the decades,” said Ms. Trainer, “but there comes a point when systems need to be replaced.” The current project includes a complete renovation of the library’s infrastructure, the creation of “modern study spaces” for students and faculty, “more suitable” spaces for students who are using digital resources. and computer upgrades. New electrical outlets are high on the list of must-haves; “staff and students would be lost without them,” said Ms. Trainer.

A great deal of attention during the renovation is being paid to making the building more environmentally responsible. “It’s a very big building that’s open lots of hours, so we feel an extra responsibility to have systems that are as efficient as they can possibly be — especially lighting; all the lighting in the building is being redone.”

Firestone Library currently houses about three million books and is growing. “We still buy almost two miles of books every year and we don’t see that changing very soon,” Ms. Trainer commented. “We also offer ebooks and we loan Kindles to students and faculty, but major research libraries like ours buy more than half of our material from other countries, and digital publishing hasn’t caught on abroad as much as it has here.”

Some recent, more obvious changes to the building include the fact that the main staircase is closed from C floor up past the third floor; a brand new, light-filled open staircase is scheduled to open in January 2013. The Trustee Reading room has been closed for asbestos abatement above the ceiling and at perimeter radiators, and a new “temporary” circulation desk has been constructed. Core work preparing for new bathrooms and service point closets is being done on the B and C levels.

“It’s gone very well so far; students are getting used to seeing workers replacing hardware on the doors,” joked Ms. Trainer, who has been University Librarian since 1996 and is the first woman to hold the post. “I think everybody on campus understands how important this work really is.”

In addition to serving and remaining open to the University community, Firestone will continue to be accessible to Princeton residents who take advantage of the cooperative “museum pass” program with the Princeton Public Library, and to local school teachers and librarians. Public exhibition spaces remain open as well.