Work to keep the People's Palace museum in Glasgow open could cost as much as £350,000, councillors have heard.
The popular attraction may need to close for two to three months while the modifications are carried out.
The work needs to be done to ensure it can remain open after the adjoining Winter Gardens close at the end of the year.
The indoor gardens are used as the museum's fire escape but the Victorian structure requires major repairs.
Council officials have been looking urgently at how to ensure the People's Palace can remain open.
A report being discussed by councillors says the museum could have to close for eight to 12 weeks while the work is done.
Councillors heard "minor adaptations" would be needed to the People's Palace but these could be reversed if necessary.
A report produced for councillors said a feasibility study produced early in October concluded that with some small to medium scale internal adaptations, the People's Palace could remain open and operational.
But it said it was unlikely that the works could be completed in advance of the Winter Garden's planned closure.
The report said the timescale for the work would be kept to a minimum and that it was estimated it would take 8 to 12 weeks.
The paper, which has been backed by councillors, gave no details of the exact modifications which are necessary and work is still being carried out to find the best solution.
The council says it is likely that the People's Palace will shut on a temporary basis while the necessary permissions are gained and adaptations are completed.
'Strong, emotional reaction'
Although it never intended to close the People's Palace long term, some reports suggested this might happen and a petition was launched to try to stop this.
Councillor Susan Aitken, leader of Glasgow City Council, said: "There was strong, emotional reaction to the possible closure of the People's Palace, which shows exactly what it means to the people of Glasgow.
"In the circumstances it is right that we have pursued a plan that will allow it to remain open independently of the Winter Gardens.
"The Winter Gardens is also a much loved part of the city's heritage, but given its ornate and detailed design it will always require a substantial and expensive programme of repairs.
"At this point it is also right that we take stock and look for sustainable options for both the Winter Gardens and the People's Palace."
Ms Aitken said it would be part of a wider look at all glasshouses and other landmarks.
She added: "It is not enough to keep pouring money into our historic buildings and hoping for a different outcome, both physically and financially.
"We need to think creatively about how we use our built heritage so that the architecture that everyone in the city enjoys does have a sustainable future.
"This will be no easy task, but developing a heritage strategy will help us to determine what we need to do protect these buildings for generations to come."
The council said the structure of the Winter Gardens was in need of repairs and the sealant used to secure thousands of windows in the glasshouse had reached the end of its life.
After a pane of glass fell into the public area of the building in 2016, protective netting was installed around the glasshouse.
The structural engineers commissioned by the council identified a number of structural issues with the Winter Gardens with the current repair bill estimated to be £5-7.5m.
At further report will be submitted to the City Administration Committee in due course which will explore options for the People's Palace, Winter Gardens and other historic glasshouse structures.