Those living in housing with retrofitted insulation are 10% less likely to develop chronic respiratory diseases such as asthma compared with those in cold, damp and uninsulated homes.
A new study by the University of Otago (Wellington) He Kainga Oranga Housing and Health Research Programme also found retrofitting insulation could also help to manage symptoms, and even greater gains could be made in homes that had heat pumps fitted.
Lead author and public health lecturer Dr Caroline Fyfe said researchers analysed pharmaceutical prescriptions that were dispensed to residents of more than 200,000 houses that received subsidised insulation through the Energy Efficiency and Conservation Authority’s Warm-Up New Zealand: Heat Smart programme that ran between 2009 and 2014.
Results showed the intervention group, which included people whose homes were insulated between 2009 and 2011, was 10% less likely to develop chronic respiratory diseases when compared with a control group whose homes had no retrofitted insulation.
Children under the age of 15 were 15% less likely.
Dr Fyfe said the results supported other studies conducted by He Kainga Oranga that showed children were less likely to develop asthma symptoms when their home environment was warmer and less prone to damp and mould.
"We also know that the longer people are exposed to cold and damp housing, the more likely they are to develop chronic respiratory disease, so it is particularly important that children have a healthy home environment."
Researchers also discovered there was a 4% relative reduction in medication for respiratory disease symptoms dispensed to the intervention group after insulation was retrofitted.
The reduction was 7% when a low-emissions, energy-efficient heater such as a heat pump was also installed.
She said the study added to an emerging body of evidence that showed onset of new chronic respiratory conditions, as well as exacerbation of pre-existing diseases, could be prevented at least in part by addressing some of the causes of cold damp housing.
"Most New Zealand houses are cold by international standards, and many were built before insulation was required.
"Retrofitting insulation is a relatively inexpensive way of not only making houses warmer and more affordable to heat, but also healthier to live in."
