Too many buildings in Christchurch are being demolished, hindering the future rejuvenation of the city, a Japanese earthquake engineer says.

Dr Kit Miyamoto, the chief executive of Miyamoto International, visited the CBD red zone last week.

He told Fairfax Media many buildings being demolished appear salvageable and more effort should be made to repair damaged buildings.

Dr Miyamoto said because so many buildings are being torn down - around half of all buildings - the CBD would become a vacant lot, making it hard to attract capital for the rebuild.


"If you have 50 to 60 per cent of vacant lots, it is going to be very difficult for people to rebuild and ... to reinvest," he said.

"You are going to see the doughnut effect. You are going to see a lot of vacant lots and people are not going to rebuild."

In comparison, only around 20 per cent of buildings in Haiti were demolished following last year's quake there.

Dr Miyamoto said areas of New Orleans where buildings had been retained and repaired following Hurricane Katrina were prospering better than those where buildings had been more widely torn down.

- Herald Online staff