Watt used information from Land Information New Zealand to make his calculations.
"The data is based on an extract of body corporate data, sourced from a simple database search done by and provided by Linz. The data provided the title reference for each body corporate, which required an individual search of the estate description field in the Linz database," Watt said.
The search covered the North Auckland district, which runs from the Bombays to Cape Reinga, Watt said, and although that geographic region was broader than what he wanted, it was the only data available for his purposes.
Watt found 58,470 titles run by the 5523 bodies corporate in the sample he got from Linz but these include suburban residential situations where some free-standing houses are in a body corporate set-up.
Excluding those pared the figures to a low of about 45,000 units in multi-unit blocks.
The most telling finds were that in the sample examined, 80 per cent of body corporate titles have nine titles or fewer with 60 per cent having four titles or fewer. One third have only two titles.
He estimated around 27 new apartment blocks were now being built in Auckland, mostly in the CBD but also in fringe and suburban locations.
That is in response to big demand for new apartments.
Watt cited Auckland Council material which said based on population projection growth, Auckland is expected to get a further 716,000 people in the next 30 years. But about 237,000 new Aucklanders are expected in the next 10 years. To accommodate them all, Auckland needs 109,000 new dwellings and 4.3 million sq m of business space.
Census 2013 data from Statistics NZ showed that in the Waitemata ward area, which includes Auckland CBD, there were 21,072 private dwellings of two or more on a site. But that includes joined-together residences, which indicates it could include cross-leases.
Nick Smith, Minister for Building and Housing, has instructed officials to examine the apartment sector, after Auckland Central MP Nikki Kaye raised issues and a report was given to Smith last month.
The numbers
• 45-50,000 the number of Auckland apartments.
• 100,000 people the number of residents living there.
• 66,000 the number of apartments needed in 10 years.