The first team could move into the building next month, with the council currently working on fitting out the space.
One of the few CBD buildings to survive the 1931 earthquake, the Napier Central Post Office on the corner of Hastings and Dickens Streets, will house the corporate services department.
The lease for the building to house the council's planning teams and their customer service operations was still being negotiated.
This building and the post office building would be ready for staff in November and December, a council spokeswoman said, should the fit-out and design go to plan.
Yesterday Napier mayor Bill Dalton said he thought council staff would be "delighted to get out" of the earthquake prone buildings.
"They are very pleased with the speed with which we were able to do it.
"It's not an ideal situation but we're making the most of it and our staff are absolutely totally dedicated to making it work."
This new set-up could be needed for up to five years, as new council premises are developed.
"It's going to be a challenge, there's no question it's going to be a challenge," he said. "But we have a staff that are absolutely able to rise to a challenge and we will just make sure it works."
With staff moving from 9200 cubic metres of space to about 3000 cubic metres, a council spokeswoman said they were looking at working differently using measures such as smaller desk spaces, sit/stand desks, reduced storage, and mobile instead of desk phones.
"These innovations were already in the pipeline and had been planned for rollout once we had completed renovations on the current site. However, with the situation we now find ourselves in, we've brought that programme of work well forward."
The detailed seismic assessments were commissioned ahead of a planned $7 million refurbishment of the office buildings, detailed in the Long Term Plan 2015-25.
Conducted by Strata Group, they showed the Civic Administration building met 10 per cent of New Building Standards and the Library building 15 per cent.
Assessments for three possible temporary library location options were expected to be returned to the council yesterday.
Council meetings will continue to be held off site around Napier as they have been since June.