The grandson of Robert McDougall says Christchurch City Council is dishonouring his grandfather's gift to the city - the Robert McDougall Art Gallery.
In 1928, Mr McDougall donated $25,000 to open the city's first public art gallery, but the Robert McDougall Art Gallery has sat empty since 2003 when a new gallery opened in Christchurch.
The gallery sits in the city's Botanic Gardens, behind Canterbury Museum.
Mr McDougall's grandson, Timothy Seay, said the building was not damaged in recent earthquakes, but the council said it needed strengthening work to reopen.
Mr Seay said the council planned to start strengthening work in 2022 and finish in 2024, but he believed that needed to be brought forward.
"I have asked them to honour the terms of my grandfather's gift and I've explained to them as far as I know it is the largest gift ever given to the citizens of Christchurch and to dishonour something like that would be dreadful," Mr Seay said.
He would also like to see the building returned to its original heritage form.
This would include the removal of custom board, which was inserted over the walls to allow the display of modern art.
Mr Seay hopes the building will be used to display more traditional art works, particularly the city's collection built up since 1928 when the gallery opened.
"I've discovered from talking to people that they feel that if the McDougall isn't retained then they'll never see a lot of the traditional art in the city's collection," he said.
Christchurch City Council manager of capital delivery for major facilities, Alistair Pearson, said the council was currently working through options that would alleviate Mr Seay's concerns.
"An options report will go to council in February 2019 for a decision on how to proceed," Mr Pearson said.
"Staff have also advised Mr Seay that the family's concerns have been noted.
"Once a decision has been made by council, staff will develop a scope of works and timeline for the repair strategy."