The Dunedin Town Hall is to be closed for 12 months during the the $45 million revamp, requiring graduation ceremonies to be held elsewhere.
The New Zealand Symphony Orchestra is likely to cancel a performance.
Major events were to have been held in the town hall during the redevelopment stage, but health and safety concerns and possible construction delays had forced the Dunedin City Council to close the town hall and the Dunedin Centre, DCC strategy and development general manager Kate Styles said.
Twelve confirmed bookings, including eight University of Otago graduation ceremonies and a concert by the New Zealand Symphony Orchestra in September, would have to be held in other venues, Mrs Styles said.
Construction work would begin in the Municipal Chambers and the Glenroy Auditorium building next March.
The town hall, which has a capacity of 2200 people, would probably be closed from May next year.
The council was discussing alternative venues with users.
The Regent Theatre and the Edgar Centre were possible options, she said.
NZSO chief executive Peter Wells, of Wellington, confirmed he had been informed by the council of the town hall's closure only yesterday.
The NZSO, which will perform at the town hall in April, was unlikely to visit in September if alternative venues were not suitable.
The council was "actively assisting" the university to make alternative arrangements, and had made preliminary bookings for the Edgar Centre and the Regent Theatre on graduation dates.
Both venues had the capacity to host graduation ceremonies, she said.
Eight University of Otago graduation ceremonies are affected by the announcement: four in December next year, three in May 2011 and one in August 2011.
University director of academic services John Price said the university would consider over the next few weeks the implications and options for its graduation ceremonies.
It was unclear what would happen to the traditional graduation parade.
Mrs Styles said the council was also in talks with the owner of the Metro Cinema, beside the town hall, which would also have to close during the redevelopment.
"It is disappointing for everyone affected by this decision.
"But, in the long run, Dunedin is going to have a town hall and Dunedin Centre that will serve it well for many more years," Mrs Styles said.
The Municipal Chambers is expected to be completed by February 2011, the town hall in July 2011 and the overall project in late 2011.
