Buildings’ $1b health price tag

Experts warn of leaky homes still being built, despite sweeping changes to the industry to try and prevent it. Tom Hunt reports.

Dean Derwin is adamant his respiratory condition has been caused by his damp house as experts warn leaky homes are still being built. He is one of a growing number of people with health problems that appear to be linked back to mouldy, damp homes built to shoddy standards.

The health costs could reach into the billions, they say, yet very little study has been done into the looming health crisis.

Derwin’s leaky home, in the Wellington suburb of Newlands, was demolished last year, marking the end of years of legal wrangling and the beginning of the businessman’s return to health.

Medical professionals were reluctant to directly link his lung sarcoidosis – described as a disease of unknown cause that leads to inflammation – to his leaky home.

Likewise, they couldn’t conclusively say the five days in hospital with pneumonia was caused by the place he and his wife once called home.

But to Derwin, his sickness and associated stress were the direct result of the damp and mould. ‘‘People handle stress differently. I thrived on it but my body broke down as a result of it.’’

New Zealand’s leaky buildings, which have been widely attributed to lax building regulations and sub-standard materials, include schools and prisons as well as an estimated 100,000 New Zealand homes.

Thomas Wutzler, a registered Wellington building surveyor said changes to the Building Code had helped fix the problems, but homes were still being built ‘‘that are leaking and need significant remediation’’.

He knew of children who no longer used ventilators after moving out of mouldy homes, as well as a person who went through three operations before realising his problems were down to mould in his walls.

Sean Edwards, from Auckland University of Technology, said doctors were reluctant to draw conclusions that a health problem was directly down to a leaky building as the evidence was anecdotal.

The financial cost of the problem was going to be ‘‘significant’’.

Otago University health professor Philippa Howden-Chapman said her group had done a lot of

People handle stress differently. I thrived on it but my body broke down. Dean Derwin

work on the subject of damp homes with mould.

‘‘We seem to find it difficult to make old or new buildings dry.

‘‘The worse the damp and mould is, the worse the health effects are.’’

Howden-Chapman said the health cost of leaky buildings was a ‘‘serious issue’’ that cost a smuch as the Christchurch earthquake.

Wutzler said two types of mould – stachbotrys and penicillium/ aspergillus – were often a danger to people’s health.

The full cost of the leaky building saga, sometimes estimated at $11 billion, was probably much higher than that – while the ongoing health costs were expected to be higher still.

A BRANZ literature review into the air quality of New Zealand homes and schools, released in January, found about six percent of housing stock – around 100,000 houses were leaky. ‘‘Numerous New Zealanders have had their health negatively impacted by this massive failure.’’

An MBIE spokesperson said ‘‘changes made to the Building Code in the mid-2000s introduced stronger requirements for the design of residential buildings to ensure they are weathertight’’.