Auckland's strategy to handle growth by upzoning is improving housing affordability, new research says.
The study, from the University of Auckland, indicates that about 22,000 new homes consented between 2016 and 2021 can be directly attributed to the city's Unitary Plan.
Implemented in 2016, the Unitary Plan allowed for about 400,000 new homes to be built across the region.
It expanded the rural urban boundary, opening up more land for development, and allowed for more two- and three-storey homes in urban areas, with up to six storeys permitted close to town centres and transport hubs.
The research compared building consents in locations that were upzoned with those that were not.
It found between 1996 and 2016, about 5.9 consents were issued per 1000 residents.
Between 2017 and 2023, after the Unitary Plan came into force, there were 9.5 consents issued per 1000 residents.
Without the Unitary Plan, there would have been 43,900 consents for new homes between 2016 and 2021, rather than the actual 65,700 consents in residential zones - a 50 percent increase.
Auckland Council chief economist Gary Blick said the upzoning played a crucial role in increasing housing capacity.
"It's been six years since the Auckland Council passed the Unitary Plan that enabled more flexible use of our residential land, and in that time, we've seen a real surge in the number of new homes being supplied.
"That is good evidence that shows we're getting more homes than we otherwise would have."
He said the low cost of development on a per dwelling basis was resulting in developers getting more yield from sites.
"Allowing for more density reduces development costs because less land is used for each new home and there is increased competition among landowners by bringing more development opportunities into play."
With more houses being built, Blick said Auckland's rental and housing prices were on a lower growth path than the rest of the country.
Between 2017 and 2024, Auckland rents increased by 22 percent, compared with 34 percent nationally, he said.
"Moreover, the University of Auckland research finds rents for three-bedroom homes were 26 to 33 percent lower than otherwise six years after the Auckland Unitary Plan was introduced."
That did not mean Auckland was affordable, he said.
"But it does show that prices are lower than they would have been without the Auckland Unitary Plan. We have a long way to go yet, but Auckland's experience shows how land use policy is a powerful lever for enabling more housing to be built."
