In a brief announcement that surprised many, Seattle's City Librarian Deborah Jacobs has announced that she is leaving to join the Bill and Melinda Gates Foundation. She will embark on the task of bringing libraries to parts of the world that have limited access to books.

We owe Jacobs much, for she ushered in Seattle's now-famous new central library and administered the largest library building program in the nation. That program brought us new and remodeled branch libraries and the crown jewel of the system, the downtown Central Library, designed by the celebrated Dutch architect Rem Koolhaas.

Great architects must do more than create a visually spectacular structure. They must also make sure the building "works." Is it efficient, comfortable, and able to do the job for which it was intended? Moreover, the architect must give the clients what they ask for. Seattle wanted a landmark building: an icon, an image that would put Seattle on the world stage.

When the City was formulating a plan for the new Central Library, City Councilmember Richard McIver asked in a public meeting, "Just exactly what do we expect to happen in this new library?" Silence followed his question, suggesting that people were stumped or that all assumed they knew the answer. But had we really taken McIver's excellent question seriously, we may have give more thought to how libraries needed to be different to match our changing ways of living and relating to books.

Koolhaas gave the city what it asked for: national recognition, architectural awards, and a breathtaking structure that attracted 150,000 people last year. Of that number, 116,000 checked out books. Others came as tourists, street people, researchers — to study, do homework, or use computers. (Plus a few who just use the escalator to avoid a hillclimb.)

The number of users in the new branch libraries is even more impressive. New and remodeled buildings designed by local architects have attracted 350,000 people, checking out an amazing 646,000 books a year. That's six times more books than at the Central Library. These branches also provide access for meetings and serve as gathering places for the community.

The flourishing branch libraries raise an old question: Might it have made sense to concentrate more resources on branches, particularly in walkable urban centers where people live, real estate is less expensive, parking is easier, and there are more attractions from adjacent businesses?

Seattle's decision to create a central library where administration, book processing, and the major concentration of books would be stored contrasts with King County Libraries, which have decentralized their libraries. The county chose to locate book processing and administration in less costly real estate and to put books near where most people lived. Seattle placed these operations in a high-priced building and in the most congested and expensive real estate in the state.

Diantha Schull, executive director of Libraries for the Future, puts it this way: "Libraries today are less about the real estate necessary for storing books, and much more about being a public forum — a space for meetings, performances, gatherings, and centers for community communication." If we want our urban villages and urban centers to serve the community, then that may be where we need to put the emphasis.

Charlie Robinson, director emeritus of the Baltimore County Public Library, makes a related point, contending that the public is choosing the atmosphere of the new bookstores over public libraries. He advocates, powerfully, that public librarians must create an environment that will attract young children and keep them coming. He warns that bookstores could empty public libraries if they don't become more inviting and convenient to match the public's busy lifestyles.

One good example of Robinson's point is Third Place Books in Lake Forest Park. Visionary entrepreneur Ron Sher has created a comfortable, inviting bookstore with adjacent classrooms, a stage, a variety of restaurants, wi-fi, and meeting areas. The store also boasts a weekly program of events that provide almost daily attractions of book readings, music, or lectures. The proximity to other adjacent businesses appears to make such stores an attractive destination for busy people who want to mix books with other life routines. Moms with kids, seniors, students, average folks on their way to or from other errands come just to read, eat, study, fend off loneliness, talk about politics. And buy books.

Aside from the question about location, we must also ask how well Koolhaas's architecture works to create "comfortable and inviting spaces," as found in cozy bookstores.

Visually, Seattle's library is a stunner. Light appears to be everywhere, and the sky is the ceiling. Steel and glass and the planes of walls intersect and recede in every direction. It so excites the eye that you can't stop looking. The exterior is a unique structure. No mistaking it for an office tower, the library looks like a massive glass box that got stepped on by the gods and set down between streets.

How it functions is quite another matter. When you wander through all the big and little spaces, you see lots of people on computers and many people obviously intent in using the library for research, study, or to peruse books. Regrettably, there are many who appear to have no reason to be there except to sleep, get out of the rain, or just hang out. How to deal with those whose motives are more the seeking of shelter than books was an issue studied at length during design work for the library. It's a problem faced by every big city library. As hard as they have tried, library security is a challenge, and Jacobs sees hiring more security as a high priority for next year's budget.

Not all Central Library spaces are inspiring. With all its sweeping structural planes, this building has an incredible amount of wasted space. Countless dreary little corners and disconnected spaces neither interest the eye nor serve useful purpose. The staff, when asked about specifics in design, efficiency, windows, convenience, storage spaces, and layout, are loyal to the library, but can sometimes roll their eyes and say, "no comment."

One major failure is the children's area. Just off the Fourth Avenue entrance (which looks like the gate to Boeing Plant 2), the children's library features color and shapes that might appeal to kids, but few seem to arrive unless special programs are set up. Children's libraries, of all the places in a library, need open sight lines so all kids can be seen by the librarian. Koolhaas has not obliged. One also wonders if the children's library would have been better located at Seattle Center with the other children's and family activities.

To my taste, this library seems emotionally cold. Almost devoid of the Northwest's natural woods, it has instead glass, metal, and plastic surfaces that are hard and industrial. It's a major departure from a living room. Startling and even grand it may be, but it's not a friendly physical space to be in. The staffers, on the other hand, are a triumph in everything you could possibly want: skilled, well trained, friendly, and really caring about doing a great job.

It's no easy matter to build long-lived buildings when how we use libraries are changing rapidly. Just think how much has changed since the last libraries were built. Now corporate libraries hire almost as many librarians as public libraries; they collect and store all kinds of proprietary information for their specialized businesses and no longer depend on the public library for technical references. Academics and researchers now depend almost exclusively on university libraries to index research papers and store highly technical information. Chains of bookstores stock and sell pop fiction to the reading public. You can buy a paperback online and have it delivered to your door for less than the cost of driving to the downtown library.