Nearly a third of New Zealand households struggle with "energy hardship" - paying their power bills, heating their home, mould and dampness.
The figure was released today by Statistics New Zealand in a first of its kind study, which also found the situation is much worse for renters and low-income families.
Half of New Zealand's poorest households say they struggle to pay their power bills on time and put up with feeling cold because they can't afford to heat their home, and 44 percent of renters say they struggle with energy hardship, compared with 22 percent of home owners.
Philippa Howden Chapman, a professor of public health at Otago University in Wellington, said her colleagues in the United States, Europe and Australia give energy hardship "a lot of attention, but this problem doesn't appear in any energy policy documents in New Zealand".
"It's a big challenge and I think people have preferred to not measure the problem so as not to have to do something about it," she said.
The research was lead by senior analyst in wellbeing and housing at Statistics NZ, Rosemary Goodyear, using the Household Economic Survey. Four thousand people are surveyed and their results weighted with population estimates.
"It's a complex relationship between poor housing quality, energy costs, low income, and also inefficient heating appliances," Ms Goodyear said.
Energy Minister Judith Collins declined to be interviewed today. A spokesperson said Ms Collins had not yet considered the research in detail.
In a statement, Ms Collins' spokesperson said: "The government has launched a number of initiatives to reduce energy costs for New Zealanders", including extending the Warm Up NZ programme, which has to date insulated more than 300,000 homes, to people on low incomes.
"In addition, recent changes to the Residential Tenancy Act require landlords to ensure houses have ceiling and underfloor insulation (where reasonably practical) by July 2019."
Statistics New Zealand wants to repeat the study every three years to track changes over time.
Ms Chapman hoped now that the research was available, politicians will act.
"We need to be thinking about how can people live in warm, dry houses, which therefore won't be mouldy, and how to ensure they can do that without still having enough disposable income so they can eat and send their kids to school with shoes and warm clothing."