The average Auckland house price could rocket to an eye-watering $3 million within 20 years, new figures suggest.
That would push them to an astonishing 19 times the average household income.
The prediction comes from statistics experts Corelogic based on a "conservative" growth rate of six per cent per year.
Reserve Bank figures show the average annual rise since 1981 is 4.5 per cent, but there have been huge upswings in the past few years - between August 2015 and August this year the rise was 16 per cent.
It means by 2036 the average house value would hit $3.25m.
Economist Shamubeel Eaqub said if prices kept rising at their current rate housing will be out of reach for most.
"Mortgage payment will rise from half of household income, to all of a family's income."
Corelogic describes their figures as a "rough projection" based on the annual house price growth rate between 1990 and 2014. The company didn't include 2015 because of the "exceptional growth period which is widely recognised as being unsustainable."
Nick Goodall, Corelogic senior research analyst, said the projection assumed the market conditions would remain static, which was unlikely.
"However, it does illustrate the potential severity of the current situation," he said.
The company found the growth in household income from 1999-2016 was 3.35 per cent. On these figures the average household income in 2036 would be $167,000.
Based on the new projection - which doesn't take into account other economic data - in 20 years time, houses would cost nearly 20 times the average income.
This affordability ratio -19.5 - would take Auckland off the chart by international standards.
According to the UN and World Bank, a house price to income ratio of 3.0 or less signifies an affordable housing market. A ratio of 5.1 or more demonstrates "severely unaffordable" housing. Auckland's ratio was 9.24 in September.
Housing Minister Nick Smith was unconcerned by the projections, which he compared to trying to predict the weather on a particular day a year ahead.
But Goodall said everything needed to be seriously looked at to ensure the country was not in the unenviable position of having houses valued up to 20 times the median income in decades to come.
Eaqub predicted the market would bust before that happened.
"But until then the rot of inequality and over-investment in housing relative to real entrepreneurship will sow the seeds of long-term weakness in society and economy. "
Economist and author Max Rashbrooke said New Zealand was heading towards a situation where the only people who could afford to buy houses would be those who could get help from others.
"Which basically means inheritances from already wealthy relatives."
Rashbrooke warned these inequalities could bring a return to a class system in New Zealand.
At the top an Auckland house owning "landed gentry" who develop "distinctive ways of thinking and habits that mark them out from the rest of country," heralding a return to Victorian times.
The chilling projection has sent a shiver of concern through homeless millenials.
"We're going to be locked out of this housing market," said Leroy Beckett from pressure group Generation Zero. "Clearly it's another wake-up call that something has to change."