About two thirds of New Zealand children are living in damp, cold homes, increasing their chances of illness, a study has found.
The Growing Up in New Zealand study is following nearly 7000 children from birth until they are aged 21.
Lead researcher Dr Susan Morton said she was surprised to find so many children living in damp or cold homes - which was one of the leading causes of the high rates of ear, skin and respiratory infections among babies and toddlers in this country.
"Half to two thirds of all of our families, whether they were advantaged or disadvantaged, suggested to us that the baby was quite often in a damp and cold environment," Dr Morton said.
"So there's definitely something about the New Zealand context that makes us think that our houses are okay."
The study also found a fifth of families could not afford to heat their home, while nearly half were forced to buy cheaper food so they could pay their bills.
Dr Morton said identifying which children were most vulnerable would help to shape policies aimed at giving them the best start.