A meeting has been told that ChristChurch Cathedral could be restored for half the price estimated by the Anglican Church.
US heritage expert Professor Marcus Brandt said the church could be repaired for about $50 million.
Professor Brandt told a public lecture in the city on Sunday that restoring the cathedral would be fairly easy compared to some of his overseas work and doesn't need to break the bank, if the right methods are used.
A master carpenter, Professor Brandt has been working alongside the Restore ChristChurch Cathedral group on a plan to restore the cathedral, which would involve shoring it up with timber frames and repairing it from the outside so no workers are put in danger.
The only major design change would be an earthquake-safe wooden steeple, similar to that originally planned for the building, which would replace the current stone one.
Professor Brandt says the building is in better condition that most people realise, which is why demolition should be halted before the pieces that are still intact are ruined.
The Anglican Church, which owns the building, says it's beyond repair and work has begun to reduce its height to just two or three metres.
The cost estimate has been welcomed by the Restore ChristChurch Cathedral group which on Saturday led a rally of about 5000 people demanding a halt to demolition work.