A detailed engineers report has identified that it will cost around $950,000 to strengthen and refurbish Pātea's Hunter Shaw Building.
At a meeting on Monday night, South Taranaki District councillors agreed to commit up to $500,000 to earthquake-strengthen the building, which was built in 1930.
The Egmont St building has been closed for some time after the 2013 Seddon earthquakes damaged it.
In 2013, the STDC agreed to get the building up to 67 per cent of the New Building Standard at an estimated cost of $350,000, before the more detailed engineers' report was established.
South Taranaki mayor Ross Dunlop acknowledged the building was part of the unique streetscape of Pātea, but was concerned at the price tag.
"We are all supportive of preserving this building, but we would like to see if we can get the costs down further," Dunlop said.
"We will also need some help to get this over the line and the remaining funds will be sought from external sources such as the NZ Lotteries Community Facilities Fund."
Funds for the council's contribution to the strengthening will come from the council's earthquake prone buildings budget.
Hunter Shaw was a farmer in Whenuakura who died in 1927 and left behind a large sum for various charitable institutions.
The building was erected courtesy of a bequest from his estate.