Bishop Victoria Matthews says the Anglican Church has always believed Christ Church Cathedral could be rebuilt, but the cost would be excessive.
The Cathedral Project Group has been considering an alternative engineers' report that says the ruins of the church are safe for workers to restore.
But the group stands by its decision that it is simply too dangerous, and too expensive, to repair the huge stone building.
Bishop Matthews told Morning Report her stance has always been the cathedral could be restored if the church was prepared to spend any amount of money.
"We've always said that it could be done," she said. "If you're prepared to spend any amount of money it could be rebuilt.''
But a replica - the ruins taken apart and put together again - would not be very satisfactory.
"Once you're at $100 million, you have to ask if that's a moral response to a desire for a beautiful building," she said.
The new cathedral will be a combination of old and the new, which she described as a renewed ancient vision, appreciating the past and recognising its journey ahead.
Bishop Matthews said she thinks the new design will have a bell tower, but conceptual drawings will not be available until the end of the year.