Leaders of the Free Library of Philadelphia have asked architects from Moshe Safdie's office to put down their dreaming pencils in pursuit of a design for the long-planned expansion on land just north of the Central Branch.

A strained funding climate is one reason for the pause. But as the recession has worn on and patrons have come to expect something different from the library, the role of an expansion in the library of the future is no longer clear. What would a new building actually contain?

As recently as a year ago, the library revealed a scaled-back vision - 80,000 square feet rather than 100,000 - and said a preliminary design would go before its board within months. More focus, and more money, would instead go toward renovating the existing magnificent structure fronting on the Parkway.

Those renovations are proceeding. But now, just about all president/director Siobhan A. Reardon is sure will go in the new building is an auditorium, an acknowledgment of the enormous popularity of the library's series of visiting authors. Montgomery Auditorium, in the current building, is to disappear in a few years when the new one opens, the space used for other purposes. The price tag for construction of the new structure, once estimated at $60 million, is now unknown.

The Free Library of Philadelphia will always be a huge repository of knowledge for casual learners as well as scholars. But as patrons increasingly look to the system for job assistance, Internet access, and an after-school safe haven for children, the library's physical manifestation is morphing as the idea of the institution evolves. In broad-brush terms, this means less on-site space devoted to collections storage and back-office functions, and more for the public. Currently, about a third of the Free Library's 300,000 square feet of floor space is open to public use. Reardon would like to see that number increased to about two-thirds.

"I want people streaming in and out, but until we give them the space to infuse the building, it's hard for them," she says.

First the library has to determine just what it has. An inventory study, expected to be done by May - there are more than one million items in the Prints and Picture Collection alone - will go to the special collections committee, which decides what will go and what will stay.

"We're reviewing every item," says Reardon.

A number of factors will be considered, including wishes of the item's donor (if applicable) and relevance to the collection. In addition to books, the library has an impressive trove of ephemera, as well as original paintings and sculpture. Warhol Campbell's Soup Can and Jacqueline Kennedy Onassis prints are being considered for sale, according to a Pew Charitable Trusts study on the library released last week.

Some holdings may have better homes elsewhere; others will be kept because of connections to the library that may not be immediately obvious, Reardon says.

"In Rare Books, we have a Manet City in the Sea]. Actually it's part of the Poe Collection. He painted it after reading one of Poe's stories," she said. "Sully's painting of Little Nell Little Nell Asleep] - it's part of a very important collection we have here ."

Another aspect of the renovations plan is to ensure that certain materials are housed in appropriate temperature- and humidity-controlled environments, which is the case already in Rare Books.

Tens of millions have already been spent. The Music Department has been renovated. A new roof, partially green, has been put on and stone on the outside cleaned. Shakespeare Park, the green between the library and Parkway, has been remade into a pleasant welcome mat of plantings and pavers. The Popular Library - the grand room just to the right on entering - has just reopened as Philbrick Hall after an extensive renovation that includes a new space for teens. These phases, costing $34 million, were paid for with a mix of public and private money. Safdie Architects has been involved in some of the work, designing lighting and signage and choosing furniture.

The next phase, to begin within weeks, is expected to cost $39 million, of which $28 million has been raised. It includes replacing six levels of ancient stacks with a modern, climate-controlled system that will both hold more materials and open up more floor space; remaking the fourth floor, including a terrace with a view of Center City, and a number of improvements to the main entrance and other departments in the building.

But for whom are these spaces being brightened, restored, and transformed?

"The work of libraries has changed more in the last decade than it did in the prior 100 years," says a passage in the Free Library's new strategic plan. "And that work will likely change more in the next decade than it did in the prior one."

The key section in the plan points strongly, and soberingly, at the expected change.

"We can envision a long era of divergence between wealthier residents of the city and other patrons of the library such as those with disabilities, new Americans, and job-seekers. A prolonged and deep divide will have a major effect on the services that the public needs from the library and on the funding model necessary to provide those services."

The library cannot, the plan concludes, be all things to all people, so it will focus on the needs of five groups: job-seekers, children under 5, entrepreneurs, new Americans, and people with disabilities.

Along with this shift, the library expects adjustments to make staffing more specialized, and to seek more private support to supplement public funding.

The neighborhood branches will continue to receive attention. Despite a project between the 1990s and 2003 in which every branch was renovated and given state-of-the-art technology, the library's $1 million a year devoted to maintenance is insufficient given all of the leaky roofs, aged boilers, and water damage. Said Reardon in the Pew report: "We have to focus on the real emergencies. As a result, some needed upkeep goes undone. Because we can't take care of things up-front, we end up with chronic problems down the line."

Still, one idea raised in the strategic plan is reopening a dormant branch in the former George Institute at 52d and Lancaster - not as a traditional library, but rather as a "Hot Spot" of technology, with computers, training rooms, and other tools for serving an immediate neighborhood that needs help with literacy, jobs, technical skills, and free Internet access.

Technology, downtown and in all the branches, will figure enormously into what the public expects from the Free Library's future, leaders think.

In support of that belief, they cite what has become - with six million visitors in the year that ended in June - the Free Library of Philadelphia's most popular branch: www.freelibrary.org.

Contact Peter Dobrin at pdobrin@phillynews.com or 215-854-5611. Read his blog at www.philly.com/artswatch.