The number of new home-building consents has fallen for the third month in a row.
Official figures show the number of dwelling consents dropped by a seasonally adjusted 6.3 percent in February to 1758.
Chief economist at the BNZ Tony Alexander said the fall was surprising given the housing shortages in Auckland and Canterbury.
He said it pointed to the unavailability of land on which to build new homes, as well as a shortage of construction workers to do the job.
Mr Alexander said the fall in Canterbury may indicate that the number of new building consents had already reached its peak.
The value of all building work consented in February rose by 12 percent to $1.2 billion.