The roughly 100-strong congregation of the Presbyterian First Church decided during its service yesterday morning to start a public appeal to fund the project.
Work began on the spire about a month ago and the scaffolding alone had taken the previous two months to erect.
First Church treasurer Les Green said there was much more work required than initially thought.
"It’s quite major."
The 56.4m spire needed damaged cladding replaced and some rust cleaned on its steel beams, caused by water running through cracks in its exterior.
So far the church had had positive feedback on the project from funding organisations it surveyed, Mr Green said.
"The vibes that we’re getting from everyone we’ve spoken to is that they’re very supportive."
The church would look to its congregation, businesses and people with connections to the church for help.
It would keep people updated on how they could give, he said.
"We’ve got to get our ducks in a row, but we’ve got to move pretty fast."
The work was expected to take six months.
The church would investigate fundraising and publicity ideas including lighting the spire up as "New Zealand’s biggest Christmas tree", he said.
The damage was identified after a Columba College Christmas carol service last year.
There was a "huge storm" and a piece of the spire fell down in front of the church, Mr Green said.
"We needed to quickly put up some basic scaffolding first and then inspect what was happening."
Earlier this year, the church completed a $250,000 earthquake-strengthening project on the building.
This was funded using the church’s restoration funds as well as money from the Presbyterian Synod of Otago and Southland, and Dunedin City Council.
The building was the second most photographed in the city after the Dunedin Railway Station, Mr Green said.
"We’ll get the work going so we can have the beauty of the church revealed again. It’s probably affected a lot of our wedding reservations."
The church was officially opened in 1873. There were two previous major renovations of the spire, in 1933 and in 1964-65.
