The new data, collated by the Ministry of Business, Innovation and Employment (MBIE), includes affordability for renters, and shows Otago is the fifth least affordable region for renters in New Zealand.
The headline finding of the new data was that renting was consistently more affordable than buying in the 12-year period the data covers, and that buying in Auckland remains ''challenging'' for first-home buyers.
Minister for Building and Construction Nick Smith said the MBIE affordability measure gave more detailed data than other measures and allowed a better understanding of housing affordability trends.
In other affordability surveys Otago fares better than the new MBIE data, in that while Queenstown and surrounds are as unaffordable, or worse, than Auckland at times because of lower wages, Dunedin and some smaller townships in Otago are more affordable.
Given the new MBIE data is almost two years behind; charting from 2003 to only June 2015, many areas such as Auckland, Canterbury and Wellington have subsequently seen different pricing trends emerge.
Unlike the monthly affordability indexes of Massey University and interest.co.nz, the MBIE measure includes renters alongside first-home buyers.
Earlier this week, Barfoot & Thompson director Kiri Barfoot said the Auckland rental market was ''under strain'' and record online registrations to view properties were attracting 44 prospective tenants per property
Average rents for the first quarter of this year rose 4.6%, from $508 a week to $531, for a three-bedroom Auckland house, she said.
MBIE is specifically looking at affordability for first-home buyers and for renters in the inaugural data up to June 2015, but quarterly reports are expected to progressively catch up on the present lag time in the year ahead.
MBIE said its new index would allow more targeted government policies to address housing affordability issues and show emerging trends
MBIE said the benchmark was established by using median income data, minus housing costs; set at $662 per week for a one-person household, or $1391 for two adults and two children, inflation adjusted.
It took into account that not all first-home buyers were earning average or median incomes and that their first house purchase might not be in the median price range, but in a lower valued dwelling range.
MBIE deputy chief executive of building, resources amd markets Chris Bunny said the new index would give a more accurate picture of how much New Zealanders spent on housing, and track whether housing was becoming more or less affordable for renters and aspiring first home buyers.
The new data said since the global financial crisis of 2007-08, renting nationally initially became less affordable, but since 2013 affordability eased down and was now more affordable than buying a first home
Nationally, housing affordability for buyers rose from 73% unaffordable to 86% during the global financial crisis, before easing to touch 81%, as at June 2015.
