A senior lecturer in civil and environmental engineering says many buildings that were not damaged in September's 7.1 magnitude earthquake will have been significantly damaged this time.
Auckland University civil and environmental engineering lecturer Hugh Morris says the level of accelerations experienced in Tuesday's 6.3 magnitude tremor were so much higher than past aftershocks that previous damage would not have made much difference to the building's which actually collapsed.
He says he understands the Pyne Gould building was built in the 1960's and major changes to New Zealand's building codes were made a decade later.
Mr Morris says buildings established subsequent to those changes would be designed to resist much stronger pressure.
He says that most timber framed houses should be safe.
