The Statistics New Zealand figures showed total residential building consents falling 9.1% in March, following an upwardly revised 4.4% increase in February.
''The sharp fall in March consents was the result of two factors: a fall in the volatile apartments component to rock-bottom levels and one less working day than usual for March due to the timing of the Easter holidays.''
Neither of those was a cause for concern, he said. Excluding apartments, consents were down 3.1%.
Canterbury was a bright spot in March, with 444 consents for homes, the highest in six years, with record numbers in Waimakariri and Selwyn districts, which were benefiting from people relocating from damaged communities in Christchurch. Compared to March 2012, consents fell by 118 in Auckland, 45 in Wellington, 21 in Bay of Plenty and 20 in Otago.
Just 16 new apartments were consented in March, the lowest since February 2010. No apartments were consented in Auckland, compared with 104 in March last year.
The total number of approvals for all building types rose 10% from a year earlier to $937 million.
The weaker consent numbers will be closely watched by the Reserve Bank, which has been eyeing heat in the Auckland and Christchurch property markets for any signs house price inflation spills over into the broader economy.
ASB economist Christina Leung said the latest figures were weak, even after taking into account the volatility of the monthly series.
''While the rebuilding in Canterbury is continuing to underpin construction demand, the trend improvement in house building demand in the rest of New Zealand appears to be slowing. This will put additional pressure on the housing market, particularly in Auckland.''
Housing market pressures were becoming a key focus for the Reserve Bank, she said. The central bank released a public consultation document on macro-prudential policy in March outlining the tools it was considering.
The subdued nature of the New Zealand inflation environment and elevated value of the New Zealand dollar meant the Reserve Bank would keep the official cash rate unchanged at 2.5% until March next year, Ms Leung said.
