Seasonally adjusted consents across all dwellings dropped 8.2 per cent to 2,245 in January, while housing consents sank 5.6 per cent to 1,646, its steepest decline since August 2014, according to Statistics New Zealand.
On an unadjusted basis, new housing consents were 13 per cent higher than a year earlier at 1,286, helping offset a 24 per cent drop in apartment permits to 89 and a 42 per cent slump in townhouses, flats, and units intentions to 185.
On an annual basis, new housing consents were up 5.7 per cent to 19,183, with all dwellings up 9.5 per cent to 27,124.
Consents in Canterbury dropped 38 per cent to 289 in January from a year earlier, while Auckland permits were up 5 per cent at 506 in the month.
On an annual basis, Auckland consents were at 9,275, still behind the 13,000 the city is estimated to need to match population growth.
"This was not unexpected after three consecutive months of strong growth in consent numbers led by Auckland and a December figure that was surprisingly strong in Canterbury, where residential rebuilding is winding down," Westpac economist David Norman said.
"A correction in Canterbury was expected, but the scale of the fall was surprising."
Monday's data also showed a pick-up in consents in Waikato and Bay of Plenty, with permits up 45 per cent and 40 per cent respectively.
The value of non-residential building consents fell 12 per cent to $310 million, for an annual increase of 14 per cent to $5.88 billion.
The value of all buildings rose 6.9 per cent to $1.07 billion in the month, and increased 14 per cent to $16.51 billion in the year.