Insulation improves wellbeing

By MARTIN JOHNSTON

People who live in insulated homes have better health and less time off work and school than those in colder, uninsulated houses.

Researchers who found this suggest it may be due to shivering families sharing more bugs when huddling in their only heated room, and the flourishing of coughs and colds in chilly conditions.

In seven communities from South Auckland to Hokitika, they checked the health of people living in 1400 older, uninsulated houses after the 2001 winter.

Half had ceiling and underfloor insulation fitted - paid for by government, local authority and community agencies - and the occupants of all 1400 houses were re-interviewed after the 2002 winter.

Once the study finished, the second half of the houses were also insulated. The insulated houses were about 1C warmer at 15C, 4 per cent drier and used less energy.

Children living in the uninsulated homes were around three times more likely to have had days off school and to have suffered a cold or flu during winter 2002 than those in the insulated ones. They were also about twice as likely to have experienced asthma symptoms.

The findings for adults were similar but less marked and included fewer GP visits. While hospitalisation rates were low, adults in the uninsulated houses were over 10 times more likely to be treated in hospital for a respiratory illness.

The statistics will be unveiled today at the Public Health Association conference in Christchurch.

One of the researchers, Associate Professor Philippa Howden-Chapman, a Wellington medical school psychologist, said yesterday that older New Zealand homes were more suited to a tropical climate than to the country's unusual combination of cold and damp.

She said only a quarter of New Zealand's 1.2 million homes had full insulation and a further quarter were partly insulated.

"Our homes are quite expensive and difficult to heat. When homes are cold it makes symptoms like asthma worse and seems to lower people's immunity to infectious disease.

"We had thought for some while that warmer homes were better for your health. This is one of the first studies able to demonstrate a small, significant effect."

The World Health Organisation recommended 18C in homes, but many New Zealand houses were at 12C or 13C in winter.

Her colleague, asthma expert Professor Julian Crane, said colds and flu might be more common in uninsulated houses because of the "huddle" effect.

"We know that one of the postulated reasons infections are more common in winter is that people are in closer proximity because they tend to huddle in a [heated] room. You could argue that if a house is warmer, there might be less close contact."

Insulated houses might need less heating, which might mean less asthma because gas and solid fuel heating could produce tiny particles that could trigger symptoms, he said.

A beneficiary of the project, Bill Wiki, said he and his family were healthier since their four-bedroom Otara home was insulated.

Originally a weatherboard house, now covered with imitation brick board, it is home to 70-year-old Mr Wiki, his daughter and her four children aged 6 to 17.

"It's dry, and still cold, but it's not a damp cold. It's really great. I've never felt better. I used to get asthma pretty bad. I put the heater on just to warm the house up and that's it. I give it a good burst in the lounge for half an hour at most and it pulls the whole house up."

Professor Howden-Chapman said that based on the trends identified by the research, several primary health organisations and local authorities were raising money to insulate some homes.

She said insulation was a good public investment. It delivered community benefits such as reduced healthcare spending and higher school attendance.

The insulation

The 1400 study houses were insulated using:

* Varying materials in their ceilings, including wool and fibreglass.

* Underfloor sisilation foil.

* Polythene on the ground.

The cost

* About $1800 a house.

* Walls were not insulated because of redecorating costs and since most heat is lost through the ceiling.