Administration officials confirmed Thursday that Calhoun, Ezra Stiles and Morse colleges will all undergo yearlong renovations, beginning with Calhoun in the 2008-’09 academic year.

Though some University officials had anticipated full-scale renovations for months, administrators did not plan for yearlong closures until the Yale Corporation discussed the project in late April, Deputy Provost for Undergraduate and Graduate Programs Lloyd Suttle said. The administration also chose to renovate Calhoun first, but no timetable has been set for work on Morse or Stiles, which are expected to be more challenging. The colleges will relocate to Swing Space during the renovations.

Yale President Richard Levin said the Corporation will likely vote to approve the project formally in September.

The University’s announcement caps months of discussion regarding the manner in which the three colleges are to be revamped. Since Calhoun was renovated in 1989, and Morse and Stiles were built decades after their peers, administrators had hoped that the three could be renovated through a series of summer projects. But an architectural report prepared by the firm KieranTimberlake Associates concluded that comprehensive renovation would require 15-month closures, Suttle said. The architects presented the final version of their report at the Corporation meeting on the weekend of April 21.

“Their clear recommendation was that the scope of work is too much to be done in one summer, or even two summers,” Suttle said.

Levin said Calhoun was chosen to be renovated first because it is an easier job for planners. Calhoun’s restoration will be similar to those of its peer colleges, while work on Morse and Stiles is complicated by the nature of the architecture and a lack of free space. A mid-April draft of the KieranTimberlake report suggested that new basement space would have to be devoted to upgraded mechanical equipment in Morse and Stiles, posing a challenge for architects trying to improve areas intended for student activities.

“It’s a simpler project,” Levin said of the Calhoun renovation. “We know what we need to do.”

Workers are already replacing Calhoun’s battered windows and expect to be finished by the end of the summer.

The order in which Morse and Stiles will be revamped remains undecided, Suttle said, partly because architects must determine the details of shared infrastructure — such as the colleges’ joint kitchen.

Morse Master Frank Keil said he would prefer that his college be renovated earlier, though he appreciates the architectural hurdles involved.

“Obviously, we’d all like to have it as soon as possible, but we have to wait our turn,” he said. “It’s going to be a challenge, but I have no doubt they can do it.”

Facilities officials said they expect the renovations to repair Calhoun’s degrading infrastructure and to bring the basements of all the colleges to par with their peers.

Calhoun needs new roofing, plumbing and electrical systems, Calhoun Master Jonathan Holloway said.

“It’s clear that although Calhoun was partially renovated 16 years ago, it needs the attention now,” he said. “We had terrific rainstorms last October, and Calhoun leaked left and right.”

Officials said they are currently seeking an architect for the Calhoun project.