Mr de Leur said there were several issues with the building.
"It fails current seismic standards, has an unstable, leaking roof and unsafe wall and ceiling linings which are a fire risk. Our Auckland Council team has an in-house fire safety specialist whose expertise we can utilise on this and other buildings."
The Rodney Local Board made the decision to shut the town hall's doors yesterday after it received a report that outlined how the building failed current Building Code requirements.
Chairman Bob Howard said board members and council officers were working with the hall's existing tenants to help them find alternative premises by the end of March.
"We know this is a popular, well-used facility but the time has come for us to face the facts. The roof leaks, the walls are a fire risk and it fails on the seismic scale too. All up, it's not good enough and the people of Warkworth deserve better."
Mr Howard said that while funding was not yet outlined, his board would work with the mayor and councillors, including Rodney Ward councillor and finance committee chairwoman Penny Webster, to discuss options.
He said the Warkworth Town Hall was a community treasure which deserved care in its 100th year.
"We recently commissioned a heritage assessment which revealed that it was originally designed as an Edwardian public building using hollow glazed bricks as cladding.
"Unsurprisingly, this design and materials predated current seismic standards. We've got the expertise on hand now to future-proof this grand old lady so she could serve our community for another century."