Ninety-seven per cent of new dwelling consents issued lead to a completed home but the lag time between the consent and start of building may be hampering efforts to boost housing supply, experimental figures released by Statistics NZ show.
Statistics NZ produces monthly building consent figures, quarterly estimates of building work undertaken, and quarterly estimates of how many homes there are in New Zealand.
But the missing piece of the puzzle was just how many consents are completed, when they are completed, and where in New Zealand they are, said accommodation and construction indicators manager Melissa McKenzie.
"While consents show an intention to build and are a good indicator of construction, we want to know how many are actually being built across New Zealand," she said.
To answer this, Stats NZ has produced new experimental statistics. The test figures show that while almost all building consents turn into homes over time, it can take almost a year from the time a consent is issued before the house-warming starts.
The estimates suggest that at a national level:
•;About 97 per cent of dwelling consents lead to a home being finished, though it dropped to about 93 per cent during the 2008 global financial crisis.
•It currently takes about 10 months for a new home to be built after a dwelling consent is issued. The lag was about six months in 1998, and 12 months in 2008.
•;About 28,000 new dwellings were completed in the year ended March 2017. Just under 31,000 dwellings were consented during the same period.
•About 1.84 million private dwellings were available in New Zealand at March 2017, comparable to the official Dwelling and Household estimates.
Labour housing spokesman Phil Twyford said the new statistics showed the government was failing to keep up with population growth.
"When compared to population data this release confirms a housing shortfall of over 30,000 homes has built up under this Government," he said.
"In the last year only 8,600 houses were built in Auckland, barely half of what was needed to keep up with population growth."
But despite the shortfall new property statistics from QV and Barfoot and Thompson this week showed the property market cooling with price falls in many Auckland suburbs.
At this stage, the new estimates are simply a test.
Stats NZ is seeking feedback to see if people find the figures useful and how they could be improved.