Undergraduates anxious to sign leases or begin room draws for next year are not the only ones at Yale with housing worries. As of right now, there are no definite plans for the Sociology Department’s future permanent home if its current one is knocked down to make room for two new residential colleges.

As Yale Corporation members grow closer to giving their final go-ahead for the construction of two new colleges, deep uncertainties have surfaced about how at least one department currently housed on or around Prospect Street will be affected.

For a decade, University planners have identified the Prospect Street site behind Grove Street Cemetery as the location best suited to house the new colleges if the University decided to build them. And, over the years, administrators quietly began finding new homes for the departments that were located in the area.

The sociology department, however, has a much less certain future.

Hammond Hall, for instance, is ready for demolition now that the University has constructed a new home for the sculpture department on Edgewood Avenue. The School of Management is set to move to Whitney Avenue, rendering Donaldson Commons obsolete. And from their current home in Brewster Hall, political science professors have spent this year watching construction crews at work on their new headquarters across the street.

“It was like, ‘If it’s going to happen, then this is where it makes sense,’ ” said a former senior University official, who asked not to be named so he could speak candidly about his former employer. “We tried to ‘protect’ that property,” he added, “and make it as large a parcel as possible.”

They succeeded. By this fall, only one concern remained to be addressed: the Department of Sociology, based in Urban and Williams halls on Prospect Street and Sachem Street, respectively. If new plans do not materialize, the department will be rendered homeless as early as 2011, when construction is expected to begin on the two new colleges.

And as the University rolls ahead with the expansion project, which now has the endorsement of University President Richard Levin in addition to the Corporation, administrators still do not know what to do about the department.

“They need to move, and there’s been no decisions made,” said Deputy Provost Charles Long.

Some specifics are known. For instance, the department’s future home will surely be somewhere in the Prospect Street area near the other social sciences, Yale College Dean Peter Salovey said.

When SOM moves to its new campus in 2011, that will free up significant space on Prospect Street; one idea, Long said, is to construct a new building on the corner of Prospect and Sachem Streets that could house the Sociology department and also provide much-needed space for economics and anthropology offices.

But nothing has been decided. “We’re still working,” Deputy Provost for Undergraduate and Graduate Programs Lloyd Suttle said Thursday in an e-mail.

In the meantime, the department has sought a number of stopgap solutions, even moving some of the offices for its growing faculty to a University-owned house on Prospect Street, department chair Karl Mayer said.

But, Mayer said, even that is not a proper temporary solution.

“It clearly has to be solved within the next one to three years,” he said. “One of the big questions is whether there will be an interim solution. The offices are very much up in the air.”

The uncertainty comes as professors claim the department is becoming larger and more popular with students than ever. Sociology professor Julia Adams said the increased number of undergraduates, graduate students and faculty in sociology has led directly to the department’s outgrowth of Urban and Williams halls.

“For me it’s obviously related to the fact that the department is growing larger and becoming ever more healthy,” Adams said. “We no longer fit inside that building anyway. We’re already exploding out of it.”

But numbers gathered by Yale’s Office of Institutional Research tell a different story. According to the OIR, undergraduate enrollment in sociology courses hit a low of 388 last year, from a high of 1,249 in the 2002-2003 school year. Twenty-three juniors and seniors currently list sociology as their major, from a high of 49 in 2003-2004.

In 1992, the administration attempted to shut down the entire department in an effort to cut costs. But when Levin took the helm of the University a year later, plans to axe the department were taken off the table and the department began a period of re-growth and hiring.

“If you look at the Sociology department, nearly every professor arrived from the mid-1990s until now,” Salovey said.

While the department’s future home remains uncertain, the University at least has some time to find an answer to that question. For now, University administrators are still considering how much the new colleges would cost, if constructed, and how the University might be able to solicit donations to pay for them.

The Yale Corporation is expected to vote later this year to formally approve the expansion project, though construction is not expected to commence until 2011.