The picture of suburban damage is becoming clearer in Christchurch after the latest series of shocks.
Fire Service Commander Dan Coward says some people came home after Christmas to find their chimney had come loose during the Boxing Day wave of aftershocks.
Fire crews have attended 200 quake-related incidents: fewer than a dozen were houses.
The number is much lower than after the first earthquake on 4 September, which was magnitude 7.1.
Commander Coward says people were right to ring the 111 emergency line, because an unstable chimney can be life-threatening.
Twenty quakes have been recorded since early on Boxing Day. The strongest was magnitude 4.9 at 10.30am, at a depth of 12km.