New Zealand home building consents declined in May, led by a drop in approvals for apartments, even as earthquake-related consents reached their second-highest monthly total since the Canterbury quakes began in September 2010.

Building consents including apartments fell a seasonally adjusted 7.1 per cent to 1,304 in May from a month earlier, according to Statistics New Zealand. Excluding apartments, there was a 0.4 per cent fall to 1,372.

Earthquake-related building consents in Canterbury totalled $47 million in May, up from $28 million in April. Of the $47 million, some $30 million was for non-residential work and $17 million was for residential work, including 47 new houses.

Since the first earthquake on September 4 there have been close to 2,000 Canterbury earthquake-related consents, totalling $428 million. That included 335 new dwellings, of which 149 were relocatable units.

Compared to the same month of 2011, Auckland had the largest regional increase in new houses, up 125, including 37 apartments. That was closely followed by Canterbury which added 100 new houses. The majority of new consents were for houses located outside the city.

On an annual basis, consents rose 20 per cent including apartments.

ASB Bank economist Christina Leung said that despite the decline in residential consent issuance over May, the underlying trend remained one of a continued improvement.

"In particular, the continued increase in consent issuance in Canterbury points to rebuilding activity gathering momentum over the coming year," she said.

While it was encouraging to see signs of rebuilding activity gaining traction, overall construction activity was still currently at fairly low levels.

"There remains little urgency for the OCR to increase, and we continue to expect the Reserve Bank will leave the OCR on hold until March 2013.