School officials announced that development Friday.
About 1,300 students at the private, Catholic school were forced to stay off-campus, with friends in other residence halls, or in temporary spaces equipped with cots in other university buildings.
The outage occurred at St. Ann, St. Martin and Assumption halls about 10:30 a.m. Thursday because a circuit breaker on a gas compressor at the school's on-campus energy center failed.
The school says the buildings will reopen by noon Sunday "under regular systems or using generators."
The outage has left the buildings without electricity, heat or plumbing.
Friday classes were canceled due to the outage, but classes will be held normally on Saturday and Monday. The school doesn't offer Sunday classes.