A campaign group says it still believes the original ChristChurch Cathedral building can be restored more cheaply than the Anglican Church says it can.
The church on Friday released more details of the estimated cost of restoring or rebuilding the central city church severely damaged in the February 2011 earthquake.
From left: Options are restoration, a traditional church or a contemporary building. Photo: SUPPLIED
A 455-page document has been made public, explaining how it arrived at the final cost for each design to restore or rebuild the cathedral.
The Church Property Trustees have presented three options: restoring the building, replacing it with a timber building in a similar style, or using a different and more modern design.
The costings have been published on the Cathedral Conversations website for each part of the process of restoration or rebuilding.
They show how much money the church has allocated for inflation, or escalated costs, in case fundraising takes up to 15 years.
The Anglican Church has put the cost of restoring the cathedral at a maximum of $221 million and the longest building timeframe at 22 years.
The Restore ChristChurch Cathedral Campaign group says it will look for savings when it analyses the detailed financial breakdown of restoring the building, but still believes $221 is too much.
However, spokesperson Mark Belton says the new figures are helpful and is pleased they have been made public.
Mr Belton says a group of qualified quantity surveyors will now go through the figures and work out where savings could be made.
"We are only focusing on the shortest term because we are strongly of the belief that the project will not take 22 years - it's more likely to take seven."
But a spokesperson for the Anglican Church, the Reverend Jayson Rhodes, says he is confident its figures are accurate.
"In terms of costings, the church is the only group who've put out costings. It's a time for engagement though, and we are engaging with a lot of different groups and are willing to take information, to hear information, to receive it.
"But the figures that we have put out ... we're standing by them. They're prepared by an internationally renowned organisation for quantity surveyors."
The details released on Friday do not cover the cost of fund-raising, but do include specifics such as the cost of removing and storing the cathedral's windows and the cost of new timber columns.
15,000 hits on website
The website set up as part of the public consultation process on the cathedral's future has had over 15,000 visits.
More than 2500 have so far provided comment on the site, which also gives people the option to vote for their preferred design.
About 500 people have attended a series of public forums on the issue in Christchurch and Auckland.
The Anglican Bishop of Christchurch says the forums have brought forward issues and options for consideration as the Church Property Trustees do further work on the proposals.
Bishop Victoria Mathews says feedback on the site as well as from the forums will be collected and reviewed as part of the decision-making process.