More than a century ago, the University proudly unveiled the most expensive dormitory at any college in American history — Vanderbilt Hall, built in 1894 for a whopping $500,000.

Within a decade, Yale may repeat that feat with the construction of two new residential colleges. This time, the price could run to almost $600 million, according to University budget projections made available to the News — making it one of the most expensive construction projects on a single site ever undertaken in the state of Connecticut.

While administrators have emphasized that no decision has been made regarding the expansion, and that student input will be carefully considered, Yale’s 2007-2008 budget lists the new colleges as one of several major “planned” projects whose cost has been carefully calculated by University planners.

Students will still have time to provide their input about the proposed colleges, administrators said. College students were invited Monday to attend five forums over the next two weeks to discuss the possible expansion. A total of six students sit on two committees formed in February to prepare a report on the expansion, and Yale officials have stressed throughout the process that the addition of two colleges is by no means a forgone conclusion.

But in the capital budget, the colleges are listed alongside several projects already considered to be set in stone — like the new School of Management campus planned for Whitney Avenue and the renovation of Hendrie Hall on Elm Street.

The entire budget projects more than $4 billion worth of construction in coming years on nearly 100 different projects. Among them are “Residential College #13 (S)” and “Residential College #14 (N),” budgeted at $264.7 million and $280.3 million, respectively, along with $48.2 million of site work to prepare for the construction of the colleges.

The addition of 13th and 14th residential colleges would be the first major addition to Yale’s undergraduate housing since Morse and Ezra Stiles opened in the early 1960s.

The Yale Corporation is scheduled to vote in February on whether to build the proposed colleges after the committees submit a report at the end of the fall semester. University President Richard Levin described the budget projections as placeholders and said the inclusion of the cost of constructing the colleges does not indicate that the colleges have been officially approved.

“It’s just an estimate of what it will cost if we go forward,” he said. If the colleges are not approved, those line items will simply drop from the budget, Levin said.

Still, Levin said if the University decides to build the new colleges, it will not spare any expense.

“It would really be a mistake to add residential colleges that did not have the kind of spaciousness and amenities of our existing colleges,” Levin said in an interview Sunday. “You wouldn’t want to create a sort of second-class status at Yale.”

And judging from their anticipated cost, higher education experts said it appears Yale is not cutting any corners with the project.

Paul Abramson, an education industry analyst for College Planning & Management magazine and president of the consulting firm Stanton Leggett & Associates in Mamaroneck, N.Y., said he could not recall another residence hall with such a high price tag. But he said it was not outlandish, considering the amenities typically featured in Yale’s colleges.

“Am I surprised by it? I’m not surprised, I’m not shocked,” he said. “It is high. It certainly isn’t what would be termed an economical construction job.”

But, he said, “You’re also talking about Yale — what would be acceptable at [most schools] would not be acceptable in a new residence hall … at Yale.”

At Princeton, the 500-student Whitman College — a residential college much like those at Yale — opened this fall at a total cost of $136 million. At Massachusetts Institute of Technology, the $94 million, 350-student Simmons Hall was believed to be the most expensive college dormitory in the nation when it opened in 2002.

The per-student construction cost of Simmons Hall was $268,000, more than quadruple the last year’s national average of $61,700 per student, according to a report by American School & University magazine. At Yale, assuming the colleges are built for 400 students each, the per-student cost would be close to $741,000 per student. For that price, the University could nearly buy three average single-family homes in the New Haven area for each of the 400 students.

The $593 million overall cost could make the combined colleges the most expensive single project on any single site in Connecticut. Several of the largest buildings in the works, like the $400 million new world headquarters for the Royal Bank of Scotland in Stamford and the $160 million Shartenberg residential tower planned for the corner of State and Chapel streets, are far less costly.

Michael Bingham, editor of Business New Haven magazine, said he could not recall any single building erected in the local area at a cost anywhere approaching the $593 million projected for the two new colleges. He said the project will almost certainly be a major boon to the region’s economy.

“Strictly based on speculation, I’m sure that would involve thousands of jobs over a period of years,” he said. “I’m sure the impact would be significant.”

The $593 million estimate is adjusted for inflation over the course of construction, according to the budget documents. Still, history would indicate that figure will creep higher before all is said and done.

A decade ago, the University’s then-vice president for finance and administration, Joseph Mullinix, predicted Yale’s residential college renovations would cost an average of $30 million per college. Silliman College, which reopened last month, cost $100 million to renovate, while this year’s renovation of Jonathan Edwards College is budgeted to cost $61.6 million.

But the $593 million estimate should be fairly accurate, Deputy Provost Charles Long said, because architects in the University planner’s office have the benefit of knowing the exact costs incurred during those college renovations.

“The minute you decide what you’re going to do, you call them in, and they sit down and talk about … what you think you need in it and they go off and try to make some estimates,” Long said. “We’ve done enough renovations, we know what it costs per square foot to [construct residential colleges].”

From there, they can approximate the cost of the new colleges, Long said.

University Planner Laura Cruickshank — whose office Long said devised the projections — did not return a phone message Monday. She has previously declined requests for interviews with the News.

When Yale last built residential colleges a half-century ago, they did not spend as freely. Morse and Ezra Stiles colleges, which were designed by legendary architect Eero Saarinen, cost $7.5 million in total, a relatively tight budget given the need to build something that could compare favorably with architectural gems like Branford and Davenport colleges.

“We have to find an architecture which would prevent these colleges from looking like poor cousins compared to the existing colleges,” Saarinen told the Harvard Crimson in 1962.

Meanwhile, Harvard was constructing two new dormitories — Leverett Towers and Quincy House — at a cost $3 million more than that of Morse and Stiles despite housing 54 fewer students, the Crimson noted.

The Corporation had been scheduled to vote on the issue of the colleges in December, but that vote was postponed until February in order to give the committees studying the expansion more time to deliberate, Levin said last month.

The 9 p.m. forums are scheduled for Wednesday in the Calhoun College dining hall, Thursday in the Pierson College dining hall, Oct. 30, in the Saybrook College common room, Nov. 1 in the Morse dining hall and Nov. 5 in the Silliman master’s house.