It's official, Wellington homes are too cold.
University of Otago researchers based in the capital have looked at 49 homes in Wellington City Council housing and confirmed they are too cold to be healthy.
The research was done before council began carrying out a 20-year programme to upgrade its social housing, with one of the aims being to make housing warmer and drier.
"Before the upgrade, housing was colder and more humid than is recommended for tenants' health," says PhD candidate Lara Rangiwhetu.
Now, researchers are calling for standards to bring all New Zealand housing up to the World Health Organization (WHO) minimum standard, which recommends indoor temperature of 18C.
The study, led by Rangiwhetu, found the temperature in the monitored houses were lower than 16C two thirds of the time. This is the temperature at which resistance to respiratory disease is diminished.
For 9 per cent of the time, dwelling temperatures were below 12C. When temperatures get to this level, they are associated with an increased risk of cardiovascular disease.
An average mean indoor living room temperature of 14.9C also appears to be colder than found in the latest national studies, with average living room temperatures for the Southern North Island recorded as 16.1C in the 1999, 2002-2004 Household Energy End-Use Project, and 16.6C in the 1971/72 Household Electricity Survey.
"This means that for a lot of the time these council houses were uncomfortably and unhealthily cold," Rangiwhetu said.
"Unfortunately, we know this is not uncommon for New Zealand housing. But what is positive is that Wellington City Council has been investing in their housing."
As part of their advocacy for healthier homes, the researchers are supportive of a number of concerted measures that council and the central Government are carrying out, including free home energy assessments for Wellington ratepayers, a voluntary WOF scheme for Wellington landlords, insulation subsidies and winter energy payments to eligible New Zealanders, and policy changes under the newly passed Healthy Homes Guarantee Act.
Other temperate countries, such as the United Kingdom, have seen a documented increase in indoor temperature, with average temperatures above the recommended minimum, so there is no reason for New Zealand not to be also achieving these temperatures in homes, Rangiwhetu said.
Councillor Brian Dawson said council had already upgraded about half its properties and wants to invest more in social housing in the coming years.
The study has been published in the journal Policy Quarterly.