More than 100 Victoria University students are being told they cannot move into their accommodation because it is deemed structurally unsound.
The university told parents in an email on Friday that engineers have advised the James Hutchinson wing of Weir House is to be closed because of "unexpected internal vulnerabilities".
A detailed seismic assessment of the almost 60-year-old building has been underway for several months, the email said.
The seismic rating of the wing has now fallen below 70 percent of the National Building Standard (NBS), the rating it was given when the last assessment was completed in 2008, the university said.
A final rating will not be determined until later this year, once detailed geotechnical soil testing is finished.
Victoria University chief operating officer Mark Loveard said while the building is still legally able to be occupied, the safety of students and staff is paramount.
"The engineer identified a number of potential vulnerabilities and one was around some of the concrete blocks in the lower walls of the particular wing.
"According to the particular design they were meant to be filled with concrete, and when we did some intrusive testing some were not filled," Loveard said.
The university considered all options before closing the section of the building, including keeping the wing open while the assessment is completed, he said.
Closing the wing now removed the risk of having to move students part-way through the year, which he said would be "very disruptive to their wellbeing, their sense of belonging and the friendships they will build during 2021".
He said all students who were scheduled to move into the wing on Sunday will be reassigned to alternative accommodation.
"We understand that this news comes at very short notice and will be an unwelcome surprise to students their parents and whānau. We also recognise this will be extremely disappointing for affected students."
He added that the moved students will not have to pay any more than they were paying at Weir House and those transferred to cheaper accommodation will pay lower fees.
"We'd just like to apologize deeply to all the impacted students and their parents.
"We know how excited they were about coming to hall and how distressing it is to find - right at the end, just before you arrive - that you're no longer in the hall you expected."