The Municipal Building is the final part of the redevelopment of the arts precinct.
Overall, the council has committed $23.8m to the Toitoi strengthening and redevelopment project and has received $9.47m of external funding, $4.75m of which was specifically for the Municipal Building re-strengthening work, stage 1 of its redevelopment.
Council group manager corporate Bruce Allan said cost estimates made in a business case to complete the redevelopment that were endorsed in August 2019 have become "more refined" with more detailed designing and costing.
This included updated costing of the fit-out estimates, based on finalised designs.
The council had been planning a community fundraising programme but this was canned due to Covid-19.
Hastings Mayor Sandra Hazlehurst said the Municipal Building is the "final element" to unlocking the full potential of Toitoi - Hawke's Bay Arts and Events Centre.
She said during community consultation about the future of the Opera House and Municipal Building, it was clear that protecting the heritage building for the next 100 years and bringing economic and social benefits to Hastings was important.
"Our vision, shaped by and for our community, is to create a place for activities and events that everyone can enjoy and feel a part of, while also incorporating cultural, educational and commercial uses, helping revitalise Hastings city."
She said when finished, the building will bring community together, provide educational pathways for young people, and showcase the rich cultural tradition of Ngāti Kahungunu and the performing arts.
"Since re-opening the refurbished Hawke's Bay Opera House and Functions on Hastings in February we have seen our community's enthusiasm to support these facilities.
"We know people can't wait to get back into the Municipal Building, to dance in the Assembly Room, to celebrate in the Shakespeare Room and to enjoy the hospitality that will be on offer in the laneways that are planned."