Masterton Town Hall's auditorium has been declared off-limits after an engineering report found it does not meet required earthquake standards.
And council staff are steeling themselves for the possibility of evacuating their offices, if a second report in July finds the offices wanting as well.
The council issued a notice yesterday at noon saying the hall would be closed with immediate effect following an initial structural survey and report.
A council spokesman said the preliminary results indicate that the reinforced concrete frames which brace the Town Hall in the transverse are at a compliance level of 20-25 per cent New Building Standard (NBS), below the legal requirement of 34 per cent.
"Council staff are in the process of contacting all groups and organisations who have future bookings in the hall and will be helping them to find alternative venues."
That includes the Art Green and Matilda Rice book launch, now shifted to the Wairarapa College hostel dining room.
"The full report is scheduled to be completed in July and once this has been received decisions can be made on the rest of the Municipal Building and the length of time that the Town Hall will be closed for remedial strengthening work."
Areas to be assessed in July include the Frank Cody lounge, the council entrance and the majority of council offices, including the mayor's office.
At present the carpark door to the building is closed, as are the toilets adjacent to the Frank Cody lounge, where council sits.
The spokesman said office staff above the auditorium have been moved to other areas.
The council's engineering and civil defence offices are up to standard. Staff have already investigated temporary options to house the council if the July report requires it to move.