An economist says pressure on the Auckland housing market is going to be intensified by increased immigration.
New Zealand has had its fourth month of migration gains with more people arriving and fewer New Zealand citizens departing for Australia.
Official figures show the country had a seasonally adjusted net gain of 1600 in April - the highest since January 2010. Migration has been trending upwards since September last year.
The managing director of Infometrics, Gareth Kiernan, says the main shift over the last year seems to have been the softening of the Australian economy and labour market.
Mr Kiernan says better economic prospects and increasing numbers of immigrants will put more pressure on the housing market.
He says the speed in which the market has turned around suggests the pressures will be more intense. He predicts the Reserve Bank's moves to bring the housing market under control are unlikely to affect interest rates until later in the year or early in 2014.
Mr Kiernan says about half of immigrants settle in Auckland - which means up to 45,000 more people a year in the city, and at least 15,000 more households.
But he believes talk about a bubble in the housing market has been overstated.
While in Auckland house sales volumes are above their historic average, he says, around the rest of the country they're still well below their historic average.
"The fact you've got reasonably high migration - or migration picking up - and you've got improving population growth does suggest there are fundamental factors which are driving the housing market up, rather than necessarily a lot of speculative activity."
He says the existence of those fundamentals could reduce some of the risks the Reserve Bank may be concerned about in the financial and banking sectors.