Te Awamutu Museum has closed after a seismic assessment deemed it an earthquake risk.
Waipā District Council evacuated the museum and an adjacent council staff building, after work to replace the roof and windows got underway.
Chief executive Garry Dyet made the evacuation call on Friday, after the building was given a Grade D rating, meaning it was at 20 percent of the National Building Standard.
"I was simply not prepared to put any staff member or any member of the public at risk," he said.
In the event of an earthquake, Grade D buildings represent a risk to occupants 10 to 25 times that expected from a new building.
About 78 staff across the council's service delivery and community services team are affected.
"We will be able to house staff elsewhere and some will work from home for a short time while we work this through," Dyet said.
"Except for museum staff, I don't think it will cause too much disruption."
The museum would be closed until further notice, he said.
While the closure was inconvenient and disappointing, the focus now would be on deciding what kind of remedial work would be required to re-open, he said.
"Right now, our priority is working alongside mana whenua, the Office of Kingi Tuheitia and the Te Awamutu Museum Trust Board to ensure all the taonga in the museum are taken care of."