A review of the Healthy Homes Initiative shows every dollar spent led to five dollars in health savings in the following five years, fewer hospitalisations and less school absenteeism.
The initiative, led by Health New Zealand but also funded by ACC and Kāinga Ora, provides support like education, beds and bedding, curtains, insulation, and heating to families living in cold, damp homes.
A five-year evaluation of the initiative, conducted by Otago University's Housing and Health Research Programme, showed it had provided more than 147,000 interventions, impacting over 200,000 people.
The report showed an 18.6 percent decrease in hospitalisations (or 10,354 averted hospitalisations per year across 186,016 people), a 5 percent reduction in school absences for illness for children, and a slight but persistent increase in wages and less need for benefits for adults.
For every dollar spent by Health NZ, there was $5.07 in health savings over the following five years.
Lead author of the report, Professor Nevil Pierse, said the 10,000 averted hospitalisations was significant.
"That's a hospital. It's a small hospital, but it's a hospital that we don't have to have because those kids never got sick in the first place, and they're not going to get sick. Those kids who weren't in hospital were spending their time in school instead."
Pierse said the Healthy Homes Standards introduced by the previous government had made it much easier to negotiate with landlords about what changes and fixes they needed to do, based on evidence from the Healthy Homes Initiative.
Reti said this report, the third into the initiative, would support the next round of funding for the scheme, which is due midway through next year.
"It sits into a contracting round, and that needs to go through due process. What we have here today provides further support for the benefits of these sorts of initiatives," he said.
Health minister Dr Shane Reti said the initiative was a positive example of social investment.
"This government is committed to the Healthy Homes Initiative, because the positive health outcomes laid out in this report clearly show that it is working," he said.
The initiative was first established in Auckland in 2013, as part of the Rheumatic Fever Prevention Programme. It now operates nationwide to eligible low-income families and pregnant people.
Health NZ said it was not a one-sized-fits-all approach, but one that was tailored to the needs of each household.