It will be at least two months before it is known if Christchurch's Catholic Cathedral can be saved.
The devastating earthquake on 22 February caused the partial collapse of the two bell towers at the front of the Cathedral of the Blessed Sacrament, causing much of the front exterior to come down.
No one has been inside the 110-year-old church since the quake because of the risk of its copper-clad dome collapsing, so no assessment has yet been made of the extent of the damage and how much it will cost to repair.
Work to remove the dome will begin next week and is not expected to be completed until mid-May.
Engineers will carry out a structural assessment of the building after the dome is lowered to roof level and debris from the towers is cleared away.
Bishop Barry Jones says the church is the spiritual home of Catholics in Canterbury and every effort will be made to save it.