The Yale Corporation decided today to proceed with planning for two new residential colleges, moving the University one step closer to its largest expansion in decades.

At its formal meeting this morning, the Corporation directed University administrators to prepare two new studies detailing the estimated cost of the expansion as well as a plan for how Yale officials could solicit donations to help pay for it. Those instructions came a day after the Corporation, the University’s highest governing body, was presented with a report by two committees charged with examining the consequences of expansion on academics and student life.

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The Corporation will not take a formal vote on the colleges until those two studies have been completed and thoroughly examined by its members, Roland Betts ’68, the senior fellow of the Corporation, said after Saturday’s meeting. It is uncertain whether that vote will come in either April or June, he added.

But Betts, in his first public comments on the expansion plan, followed University President Richard Levin’s endorsement of expansion on Monday with a ringing endorsement of his own.

“If you’re ever going to expand, this is the right time to do it,” Betts said, citing Yale’s robust health as an institution at this point in its history. “You have an unbelievably precious resource here called the Yale education, and you sort of have a duty to provide it to as many people as you possibly can.”

The decision to proceed was seen by many observers as little more than a formality, especially after Levin’s public endorsement of the expansion plan this week. And, indeed, the Corporation did not hold a vote on the matter, instead reaching a consensus to continue planning, Betts said.

The expansion plan — in the works for a decade but not announced for public consideration until last February — calls for two residential colleges to be erected along Prospect Street behind the Grove Street Cemetery, a location that has been criticized by students as isolated from the central campus.

Only one in four students supports the expansion plan, according to a campuswide poll conducted by the News earlier this month. Many students have argued that expanding, especially given the location in question, could ruin the quality and intimacy of the Yale College experience.

But from Levin’s point of view, expansion could make that experience even better — as well as help the University expand on its mission.

“I believe that it is time to use our augmented resources to prepare a larger number of the most talented and promising students of all backgrounds for leadership and service,” he wrote in a statement to the Yale community Monday.

The new colleges would enable the University to ease overcrowding in the existing 12 residential colleges and also to bump the undergraduate enrollment by more than 10 percent, to about 6,000 students in total. A preliminary budget estimate placed the cost of the colleges at no less than $600 million in total.

But Provost Andrew Hamilton dismissed that figure as an extremely imprecise estimate and said that his office, with the assistance of Vice President for Finance and Administration Shauna King, will need to develop a much more precise estimate for the Corporation to consider in the coming months.

The obvious calculation, and perhaps the simplest, will be for the actual construction of the colleges. That includes both the buildings themselves as well as enabling costs, ranging from preparing the site to improving infrastructure in the area, officials said.

More complicated, perhaps, will be the many expenditures related to “scaling up” the operation of Yale College to accommodate a larger enrollment. The committees’ report, released Monday, emphasized 15 recommendations that the University should pursue if it chooses to expand, and many of the recommendations would bring with them extensive costs, ranging from hiring dozens of new faculty members to adding bus routes and police patrols in the Science Hill area.

Corporation members discussed the report on Friday with many of the 34 faculty, students and administrators who served on the two committees. Betts said the discussion was a valuable one, especially as it pertained to many of their recommendations for ensuring that expansion strengthens Yale College, rather than detracts from it.

“We’re really on the same page there,” Betts said. “The issue is: If you’re going to expand the University and if you’re going to add a couple of new colleges, just make sure that you don’t compromise what is at the heart of the Yale experience.”

Levin, who was absent from the meeting because of a family emergency, was unavailable for comment Saturday.