The "appalling third world conditions" of Auckland's state housing are making children chronically sick, a leading doctor says.

GP Dr Lance O'Sullivan recently moved from the Far North to Auckland, and said he "thought he knew what poverty was".

On his second day working in Auckland he met a 28-year-old single mother, raising two boys, aged four and nine, who feared her home was contributing to their poor health.

Her youngest son was chronically unwell with asthma and respiratory problems. O'Sullivan said he asked her why.

READ MORE:

* Landlords get our money, we get poor health

* Renting family say they are stuck in a house that is making them sick

* Dr Lance O'Sullivan: Penalise parents who won't vaccinate their kids

* Lance O'Sullivan could be a future National Party leader

"She looked up at me and said 'Dr Lance, I think my home is making my kids sick'."

When O'Sullivan asked to see the home, it was cold, damp and had mould on the walls and ceilings, he said in a video posted to Facebook.

Water was also dripping inside the rooms where the boys slept.

MONIQUE FORD / STUFF Dr Lance O'Sullivan says rental properties owned by the government are in 'third world conditions', burdening New Zealand's health system.

O'Sullivan said it was something he "never thought he would see in this city".

"I asked her who her landlord was, and she told me it was Housing New Zealand," he said.

O'Sullivan issued a challenge to the Minister of Housing Phil Twyford to talk to the Minister of Health David Clark about the condition of Auckland's state housing.

The government declared it had introduced measures to make homes healthier, including that landlords must ensure homes meet minimum standards.

SUPPLIED/HRV STATE OF HOME SURVEY O'Sullivan said the state of the woman's house was something he 'never thought he would see' in Auckland. (file photo)

But "they are failing the people of this country," O'Sullivan said.

"I can't fix these kids if you don't fix these homes."

Mould and damp in New Zealand homes has been linked with the country's high rates of asthma.

One in nine New Zealand adults have asthma, compared to one in 20 worldwide.

In addition, respiratory disease is the third leading cause of death here.

To help tackle the problem, O'Sullivan said he had set up a Facebook page, called My house makes me sick, where he wanted people to share their stories with Twyford.

Since creating the Facebook page he has been contacted by a number of people with similar stories.

This was "concerning," he told Stuff on Monday.

"It shouldn't take me to highlight this problem for Housing New Zealand to take notice."

ANDY JACKSON/STUFF Acting Housing Minister Carmel Sepuloni said the state of the woman's house was 'unacceptable'.

Acting Housing and Urban Development Minister Carmel Sepuloni said the government shared O'Sullivan's concerns about the state homes New Zealand children were living in.

"We don't believe any child should live in a home that causes them to get sick and unlike the previous Government we've introduced rules that prevent landlords from profiting off such homes."

Safe, warm homes were a priority, she said.

"One of the first things we did is create a healthy home guarantee to make sure every rental home – including HNZ homes – keep families warm and dry."

The state of this particular house was "unacceptable" and Housing New Zealand would be visiting the family on Monday afternoon, Sepuloni said.

The government has already built more than 740 state houses since coming into office and were investing more than $4 billion to both building thousands more and renovate existing houses, she said.