A group is being established to work its way through earthquake-hit central Christchurch to secure damaged premises and reassure anxious business owners.
Civil Defence said on Wednesday work in the red zone will begin over the next couple of days.
National controller Steve Brazier says the move follows discussions with business owners worried about the safety of their possessions.
Mr Brazier says heavily-controlled access to parts of the CBD will begin on Monday and more details about that will be confirmed on Friday.
In the interim, broken doors will be secured using plywood or heavy plastic.
Mr Brazier says he can not guarantee that all broken shop windows will be boarded up, given the extent of the damage, but the group will do its best.
Twenty-three demolition companies have been accredited to work in the CBD and they have no rights to salvage anything from the buildings, he says.
17 buildings demolished
Civil Defence Minister John Carter told Parliament on Wednesday that 17 buildings have been demolished without the owners being told first.
Mr Carter told the House that 139 buildings in central Christchurch were knocked down following the quake and thorough efforts were made to contact owners in advance.
Mr Carter said of the 17 demolished without the owners' knowledge, 12 came down before 8 March when the search for survivors and the recovery of bodies was the primary focus.
The buildings were demolished under the authority of the Civil Defence Act.