The Historic Places Trust is still trying to gauge the extent of the damage caused to heritage buildings in Christchurch since the magnitude 7.1 earthquake on Saturday.
Southern region general manager Malcom Duff told Morning Report that buildings like Christchurch cathedral and the arts centre have fared well, with very little apparent damage.
But he said the trust has 83 category category one buildings in Christchurch.
Mr Duff said there's been widespread destruction and a permanent loss to the heritage of the area, but it will take some time to actually quantify.
Christchurch City Council says many of the city's character buildings have fared well, including the cathedral, the arts centre and Christ's College.
But the Repertory theatre in Kilmore Street is extensively damaged, just months before a major restoration project was to begin.
Meanwhile, Civil Defence has ended a ruling that public buildings need to be inspected before reopening.
It earlier issued a requirement that all public buildings - such as Government offices, council facilities and educational insitutes - had to remain closed until inspected by a structural engineer.
Civil Defence now says it recognises some businesses provide essential services that cannot otherwise be met.
But it says property owners are responsible for making sure their property is safe for employees and the public.