An engineer’s seismic assessment indicated the main Te Hononga Civic Offices building off Hereford St is 100% of the New Building Standard (NBS), but the annex floor connections on the Worcester Boulevard side are at 40%.
Council chief executive Mary Richardson said while the NBS rating for the building is above 34% - meaning it is not quake-prone - the annex floor connections could behave unpredictably or fail abruptly during a strong earthquake.
"The likelihood of a large earthquake is considered low, however, based on the potential consequences and the temporary mitigation measures available, we have determined that the council should continue to vacate the annex area," Richardson said.
"Safety of council staff, elected members and visitors is paramount and after discussing the risks, mitigations and options with the council engineers and the executive leadership team, we’re not willing to take any risks on that."
The design and seismic strengthening of the building is expected to take up to six months.
"There is an advantage of the annex (being) unoccupied over this time to allow for investigation and then construction works to happen as quickly as possible. Although we are still working on logistics for how the remedial programme will run," Richardson said.
"Due to the longer period of restricting occupancy of the annex, we will be looking at options to improve the working environment for staff and elected members, particularly those who have been relocated."
The entrance on Worcester Boulevard has reopened and the civil servant café is operating with some tables in the main building.
"Having assessed the usage of the Worcester Boulevard ramp and entrance, we consider there is a lower risk to users of this entrance due to the shorter time the area is occupied," Richardson said.
"Once again, I want to thank staff for continuing to provide advice and services to our residents, in spite of the disruption, as well as the mayor and councillors and visitors to our civic offices for their patience and understanding."
