Dunedin City Council confirmed no seismic assessment has been completed for the heritage building.
Council meetings have been shifted out of the building, possibly for three years, while the internal structure is analysed and ahead of possible further strengthening work.
Council corporate and quality general manager Robert West said the council was in a discovery phase for the project to understand any issues.
"This includes site-specific seismic modelling, which will give us the information and evidence to accurately determine the level of risk and inform the programme of work," Mr West said.
"During this discovery phase, we will use a variety of approaches and specialists to help us form the complete picture."
In November 2020, some ornamental Oamaru stone fell from the building, which is more than 140 years old.
Scaffolding and netting were put up around the chambers building and town hall as a precaution and detailed investigations started last year.
An external three-dimensional model of the building was completed and the internal structure is to be assessed next.
The council has described this work as being part ofefforts to preserve the integrity of the building and its future.
An initial $3.3 million was allocated to the project in the council’s 2021-31 long-term plan.
Mr West said last week meetings needed to shift because ofnoise and disruption during the next phase of investigation.
There was no further impact on council staff or operations, at this stage.
"As our programme of work develops, this may change."
Mr West said the modelling work, both exterior and interior, was one tool for helping the council better understand the building and what might need to be done.
The exterior 3D modelling had successfully demonstrated the value of this approach, he said.
Mr West described it as advanced technology and said it was faster and more accurate than traditional approaches.
Some strengthening work was carried out in the Municipal Chambers when it, the town hall and Dunedin Centre were upgraded in 2011.
About 20 steel reinforcing beams were added in the chambers building to strengthen it against damage from possible earthquakes, as part of a $5 million refurbishment.
