Council chiefs are being forced to spend £15,000 repairing leaks on one of their flagship projects.
Bosses say "inclement weather" has caused issues at the Grain Exchange in Ayr High Street, opened just two years ago.
The former Clydesdale Bank building was renovated with a view to staging craft markets and housing council staff.
But the project was beset by problems and delivered two years late in 2019.
Workers were due to move in early this year but leaks – blamed on loose guttering – has caused scaffolding to be thrown back up around the building.
South Ayrshire Council bosses say it will take a number of weeks to "investigate the full scale of the damage and repair".
The latest setback has drawn criticism over the council's handling of the building.
Tory Martin Dowey, who leads the opposition on the council, said: "I am shocked but once again not surprised that a building, which was two years late and is not even occupied by council staff, is already in need of remedial work to the roof because of apparent inclement weather.
"Well, we tend to get a lot of inclement weather in Scotland and this is a building that has stood in Ayr for well over 100 years.
"To my knowledge it has had no water ingress issues prior to the council getting its hands on it.
"Questions need to be asked why this was allowed to happen and why it was not picked up at the time the building was handed over to the council – supposedly as a finished building."
A council spokesperson said: "We have been working on the fit out of the upper two floors of the Grain Exchange over the last six months.
"We recently identified water ingress on the upper floor of the property.
"Initial investigation has suggested that the recent inclement weather may have caused some of the guttering to be displaced.
"Fortunately we still had a contractor working on the building so the issue was picked up immediately and repairs were instructed.
"These will consist of one week to erect the scaffold, three weeks to investigate the full extent of the damage and repair, then a final week to dismantle the scaffold.
"As this is a now a council-owned property, we will be paying for the repair/scaffolding works (approximately £15,000).
"However, we will seek to mitigate these costs and claim against our insurance policy if possible."
