A survey has found that there is mould in almost half of the country's rental accommodation.
The HRV State of the Home online survey also found that renters take more sick days than the national average.
Professor Charles Crothers from AUT, who wrote the survey questions, says the results show action is needed immediately to improve rental accommodation.
He says a Warrant of Fitness for properties should be a priority.
"We insist on quality standards for all sorts of other things, electric equipment, cars, surely housing is in many ways more important than the rest of it, because it's the framework within which the rest of it sits."
Almost a third of the renters who took part in the survey said they had moved out of a home because it was cold damp or mouldy.
The online survey had 1405 respondents.