A geologist advising Civil Defence in Christchurch has warned that a significant number of homes on the Port Hills may have to be abandoned.
Mark Yetton told a meeting of Sumner residents on Sunday that the risk of rockfall will be insoluble in some places.
Mr Yetton said most parts of the Port Hills, and the homes on them, remain stable and unaffected by the quake of 22 February.
But he believes people will have to retreat from the most risky hill areas, just as they will in places like Bexley, now that active fault lines have been discovered.
Mr Yetton said the magnitude 5.3 aftershock on Saturday brought more rocks down in the hills and some crashed into homes that had been evacuated.
More than 400 hillside homes between Opawa and Taylors Mistake have been evacuated precisely because of that risk.
Civil Defence National Controller John Hamilton told Morning Report that no more houses will need to be evacuated, but scientists must reassess the stability of the ciffs.
He said it will be June at the earliest before some residents know whether they have to permanently abandon their houses.
The Earthquake Commission says hillside residents don't have to wait until a rock hits their house to take action: it's advising anyone facing that risk, to make a claim now.