The Federal Court has ordered all work stop on the demolition of Bruce Hall until Tuesday.
The Bruce Hall Alumni Association sought the temporary halt on Saturday amid fears the demolition would be irreversible before its challenge to the works was heard next week.
Judge John Griffiths prevented the university "from doing any work involved in demolishing any part of the buildings comprising Bruce Hall" until 10.15am on Tuesday, when the matter will be heard.
Bruce Hall Alumni Association president Bec Duncan said her organisation feared dismantling of the buildings meant "they wouldn't be worth saving" if work continued through the weekend.
"The Bruce Hall Alumni Association did this as a last resort," Ms Duncan said.
"Courts don't give these orders lightly, but we believe we have a reasonable prospect of success."
The National Capital Authority approved the demolition of Bruce Hall's accommodation wings in February, while permission to demolish the dining hall was granted last month.
The association lodged a challenge against the demolition in the Federal Court on Tuesday, after the Australian National University began the demolition process and asbestos removal.
Ms Duncan said the association wanted the matter resolved as quickly as possible.
"We don't want to hold it up, whichever way the decision goes," she said.
"We have no desire to stop the building if the court decides against us, because we want the students to be able to move into their accommodation as soon as possible."
In a statement, an ANU spokesman said the university would comply with the order.
"ANU has been proceeding with the redevelopment of Bruce Hall in accordance with approvals granted by both the National Capital Authority and the Department of Environment and Energy," the spokesman said.
"ANU will comply fully with any court order in relation to the project and at the earliest available opportunity seek to ensure the redevelopment continues for the benefit of all students and alumni."