When Harvard Law School students take their final exams this winter, they won’t have to worry about drinking coffee to wake up for early morning exams.

The Law School notified the student body yesterday that in-class exams will be held during the late afternoon from Monday through Friday, and take-home exams will be given on Saturdays and Sundays, to accommodate construction of a 250,000-square foot complex on the northwest corner of the campus.

Construction could not cease during exams because delays could cost the Law School more than $15 million, according to an e-mail sent to students yesterday by Ellen M. Cosgrove, dean of students, and Leslie Sutton-Smith, the registrar at the Law School.

“As with any project of this scale, there are some associated costs beyond the obvious financial ones,” the letter said. “We are doing our best to make sure the construction has minimal impact on your Law School experience, but some disruptions are inevitable, and when they happen, the Law School community will need to work together to overcome them.”

The e-mail said that noise from construction would likely make it impossible for students to concentrate on final exams in classrooms and dormitories near the site.

On the Law School campus, some students said that the new exam schedule could interfere with pre-arranged travel plans.

“I think it could be inconvenient for people who already bought a plane ticket,” said Miriam L. Glaser, a second-year student, who lives in New York. “It’s not inconvenient for me, but I can definitely see it being a problem for other people.”

Nicholas F.B. Smyth ’05, a second-year representative in the Law School’s student government, added that some students have expressed concern over the transition from morning to afternoon exams.

“I don’t think anybody is happy to have to wait all day to take a test rather than just doing it in the morning like we’re used to,” he said.

But Law School spokesman Michael A. Armini said that while the school understood students’ concerns, the administration determined that changing the time of exams was the best course of action.

“A lot of people might come up and say that there are problems,” Armini said, “but the intent is to make it better.”

The complete exam schedule will be posted on the Law School’s Web site in the upcoming days, according to the e-mail.

The new facility, set to open in 2011, will include student spaces, classrooms, and rooms for clinical programs.

—Staff writer Kevin Zhou can be reached at kzhou@fas.harvard.edu.