Planning for new houses across the North Island has jumped by nearly 25 percent for the year, but growth in Auckland is lagging behind other major centres.
It comes as a legal challenge to the Unitary Plan threatens to slow development in New Zealand's main city.
Nearly 30,000 new homes were consented across the country in the year to September, up 14 percent on the same time in 2015, according for new data from Statistics New Zealand.
But while consents in the Bay of Plenty were up by 50 percent, and Northland saw a growth of 40 percent, Auckland only gained 14 percent in consents for the period - although it still made up the largest increase in dwelling numbers.
For the month, overall consents were largely flat from August (up 0.2 percent), compared to a drop of 1.5 percent the month before.
ASB senior economist Jane Turner said while the underlying trend was still encouraging, growth could be threatened by an ongoing legal challenge to Auckland's Unitary Plan.
Lobby groups Auckland 2040 and the Character Coalition have asked for a High Court judicial review of higher-density residential zoning in some areas, threatening to freeze development in parts of the city for up to a year.
"Against a back drop of strong population growth, an ongoing sluggish housing supply response could still add additional pressure to house prices," Ms Turner said.
"Recent legal challenges to the Unitary Plan bring some uncertainty around its implementation. This could impact developers and potentially slow Auckland's much-needed supply response."
In the South Island however, consents were down by 3.9 percent, with a 11 percent decline in Canterbury dragging down growth elsewhere.
"Canterbury consent issuance has resumed its downtrend as it winds down from the rebuild peak," Ms Turner said.