Rents and rates are making up a bigger proportion of household spending and a body representing landlords says rents could rise further.
Statistics New Zealand's household economic survey shows total housing costs as a proportion of income increased from 15.1% to 16% in the two years to June.
Weekly spending on rent was up 6.6% for the period, while property rates were 9.3% higher.
Property Investors' Federation president Andrew King says property owners could increase rents further to align with the increase in rates.
He expects the real impact will be when landlords do their tax returns next year and realise they have gone backwards.