A new survey reveals half of rental homes are mouldy, yet most landlords are ignoring the problem.

The latest HRV State of Home Survey questioned 1450 people about the quality of their rental properties and found mould is prevalent in 48% of all homes rented.

Charles Crothers, Professor of Sociology at AUT, says the survey shows New Zealand is now in a "renters-versus-the rest situation".

"Those who are renting are more likely to suffer a lot, with a quarter suffering from a cold home and 20 percent living in houses that are difficult to heat."

Prof Crothers says sub-standard housing also has an effect on renters' health.

"[They have] on average 3.6 sick days a year compared to an overall average of 3.1, they are less likely to think about retirement savings, and they feel vulnerable when thinking about the future because they find it hard to save."

The survey highlights a stark difference between the mentality of landlords and their tenants. Forty percent of tenants said they would like their landlords to make their homes healthier, however only one-quarter of landlords would like to make the investment.

Almost 40 percent of renters have contacted their landlords about the cold, damp and mouldy conditions of their homes but many were unwilling to do anything about it - 56 percent of landlords did nothing about their complaints.

"We had to replace our bedroom carpet because of black mould as the landlord didn't care. Since then our new carpet has turned mouldy," said one renter, who wished to remain anonymous.

Many tenants are happy with their accommodation but more than 20 percent do not believe their house was worth what they paid for it.

Only 11 percent of landlords focus on mould and dampness. They are much more likely to work on damage repairs (35 percent). One fifth of all landlords spend less than $1000 per year on maintenance.

When trying to heat those cold and damp homes, 67 percent of people opt for a heater or heat pump to stay warm however many people resort to less expensive options.

Almost a third of renters have moved out of a home because it was damp, cold and/or mouldy.

Andrew Little's Healthy Homes Bill passed its first reading on May 5, which would ensure all rental homes in New Zealand are warm and dry and includes a requirement for a heating source in every property.

The Bill requires minimum standards to be set for heating, insulation, ventilation and drainage in rental homes.

Prof Crothers says it is key that current homes are brought up to standard and that new homes are built to a high quality.

"The Healthy Homes Guarantee Bill will bring rentals up to standard but it can't stop there, because it's clear from the survey results that the housing stock in general is not in great shape and people's health is suffering because of the state of their home."

Newshub.