Insulation improves health

Insulating houses can significantly improve health and reduce days off work and school, according to a new study in this week's British Medical Journal.

The state of housing has a real impact on health; cold houses place more physiological stress on people, and are more likely to be damp - leading to respiratory problems. Despite the fact we spend about three-quarters of our lives inside, little is known about the specific health effects of the indoor environment.

So researchers at the University of Otago in Wellington, New Zealand, identified 1350 uninsulated households, all from low-income communities.

The properties were split into two groups. The first did not have insulation installed, whilst properties in the second group were fitted with a standard insulation package, which included ceiling insulation and draught stopping around doors and windows.

The researchers then used interviews, questionnaires, occupants' self-reported experience, energy usage, house temperature and other environmental characteristics to measure the effects.

Insulation led to a significant increase in indoor temperature and a drop in relative humidity.

People in the insulated properties reported that their houses felt significantly less damp and mouldy, were less likely to suffer from wheezing or colds, and spent less on heating their houses. Adults and children in insulated houses were half as likely to take days off work or school than those in houses without insulation.

The authors conclude that "interventions of this kind which focus on low-income communities and poorer quality housing have the potential to reduce health inequalities. Retrofitting insulation is a cost-effective intervention for improving health and well-being."

This new trial emphasises the benefits of investing in housing, which are not limited to health, say researchers in an accompanying editorial. This evidence, and emerging evidence from other housing studies, should inform policies linking housing investment to impacts on health, they conclude.