Essential repairs will mean the major concert hall at Huddersfield Town Hall will close for 20 weeks.
The hall will be out of bounds from March until August next year while vital work takes place to the roof.
It affects 30 bookings already made – some by regular hirers who are now being contacted by Kirklees Council officers and offered alternative options.
Kirklees town halls manager David Roche said: “It has been established that the roof over the concert hall is in need of essential work to protect the future of the buildings to ensure it stays wind and water tight.
“We don’t want the roof to affect the overall fabric of the building – the concert hall ceiling with its ornate features or the Father Willis organ – and to ensure health and safety is maintained we need to do this work.
“It is about preserving this asset and making sure the concert hall is protected in the future. It only affects the concert hall – other than that it’s business as usual at the town hall.”
The council’s physical resources and procurement department assessed the roof and say 20 weeks is needed for the work to take place at the Ramsden Street building.
Work is set to get underway from March 2016 and finish in August, with Mr Roche saying the spring and summer months were the best time to get the builders in weather-wise and it was also the quietest period for concert bookings.
Some of the 30 bookings are council functions such as the mayor-making ceremony which can be relocated to other council venues.
Mr Roche said they hoped to accommodate the external bookings at other Kirklees town halls or reschedule them, adding: “We have a great team that has done a lot of work to pull this together and are contacting those affected.
“It’s not ideal for them, but we want to support them in the process and find suitable alternatives.
“Up until last week we were working on plans to work around the bookings, but it became evident that wasn’t going to be an option.”
The main concert hall can seat up to 1,200 people, making it the biggest venue in the council’s live events portfolio.
Special plans to protect the Father Willis organ are being drawn up, which will see it sealed off to protect it from dust or rising temperatures that can affect its sound.
Other Huddersfield Town Hall services, including the register office, council chamber, conference and meeting rooms are unaffected by the work.