More than 700 commercial buildings in Christchurch have now been red stickered after last month's earthquake.
That means they are unsafe to enter because of damage or threats from neighbouring constructions or landslips.
Another 721 were given red placards after being inspected.
Slightly fewer, 711, received a yellow placard, while 1891 have been declared safe with green stickers.
Of the 837 heritage buildings inspected, 338 received a red placard.
Civil Defence national controller John Hamilton says some heritage buildings simply cannot be rebuilt.
Meanwhile, demolition crews are bringing down whole blocks of devastated buildings in the CBD.
Radio New Zealand's Rachel Graham was among the reporters taken on a tour of the restricted red zone today.