More than 200 council staff are being moved out of Napier's Civic building and Library after earthquake tests revealed the buildings are unsafe.
The Napier City Council said seismic tests show that both buildings have structural deficiencies.
It said the Civic building, which includes the council's chambers and mayors office, is unlikely to be fixed.
IRD has already moved its 78 staff out out of the Library building, which will receive strengthening work.
The council's infrastructure director Jon Kingsford said staff would be moved out of the civic building in the next few days, while the library staff would be staggered.
"So the strength of the building hasn't changed but the standard has gone up.
"So we are found to be wanting in terms of that new standard."
Mr Kingsford said the public would still be able to access the library as it has a higher rating than other parts of the building.
He said the council is discussing new sites with commercial landlords.