Toxic rot crisis in new homes

By ANDREW LAXON and EUGENE BINGHAM

Thousands of new homes are now believed to contain serious leaks and rotting timber frames, creating a national repair bill estimated at $1 billion and a health threat from toxic mould.

Concern over the "leaky building crisis" - and its effect on property values and confidence in the building industry - has already prompted the Government-appointed Building Industry Authority to launch an inquiry into how many homes are affected.

But the Weekend Herald has discovered that the problem is far bigger than most homeowners realise.

Well-placed industry sources say one in 10 new homes - 2000 of the 20,000 built each year - are at risk of leaking and dozens of large-scale developments built in the past five to 10 years, some with 100 units or more, have serious problems that are only now becoming public.

Few industry experts were prepared to be quoted on the scale of the problem, citing their commercial and legal obligations.

But one Auckland building repair specialist, Steve Alexander, said he was investigating leaks at 560 units spread across 49 properties, including 10 multi-unit developments.

In the past few years he had dealt with at least as many cases again.

And a biodeterioration expert at the Forest Research Institute in Rotorua, Robin Wakeling - who studies building materials affected by damp and rot - said the scale of the damage in new houses was just starting to emerge.

"We are aware of hundreds of properties which have been affected and those would be representative of many thousands that have been built in the past five years.

"On that basis, we've only seen the very beginning of the problem."

Scientists are also monitoring an increase in the growth of a potentially lethal fungus, stachybotrys, and other toxic moulds believed to cause health problems, including breathing difficulties and flu-like symptoms.

Microbiologist Dr Nick Waipara, who is studying the extent and health implications of mould in homes, said poorly constructed modern homes were providing the perfect breeding ground for stachybotrys, which thrived on damp conditions.

Weekend Herald investigations have established:

* The company behind one of the country's biggest housing developments, the 153-home Sacramento at Botany Downs, has acknowledged that the units are not waterproof only two years after they were built.

* Parts of a block of terraced houses in Rose Rd, Ponsonby, had rotted so badly that a double bed and a washing Machine fell through the floorboards.

* Marion Square, a six-year-old, upmarket 40-unit apartment complex in inner-city Wellington, was contaminated with stachybotrys and leaked so badly that entire inside walls needed replacing.

Residents of Marion Square and Rose Rd are suing the builders. Rose Rd owners are also suing the Auckland City Council, alleging that it failed to properly oversee the building process.

The leaky building problem is caused by a combination of factors: design changes, such as flat roofs and no eaves; the replacement of weatherboard and brick by new claddings; untreated timber which rots more easily; and declining building standards. Experts disagree over which is most important.

This week, building inspectors were told that the cost and frequency of leak problems were rising.

A survey of 250 new housing units which needed repairs found the total bill was $8 million - an average cost of $32,654 a unit.

The research by building repair specialists Prendos covered 50 sites built since 1990, mainly in Auckland. The average house was five years old, two to three storeys and worth $450,000.

Author Philip O'Sullivan found 1420 leaks - an average of 5.7 leaks in each unit.

Buildings on four sites had had major repairs but still needed to be fixed again.

Mr O'Sullivan, an industry crusader against leaky buildings, has predicted in the trade press that the long-term repair bill for the country will easily top $1 billion. Others believe it will be higher.

Some experienced observers fear New Zealand's problems could turn out to be as bad as Canada's "leaky condo" scandal, which created a crisis of confidence among homeowners and in the building industry.

In Vancouver, experts believe that close to 90 per cent of the 800-plus three- to four-storey, wooden-frame condominiums built between 1980 and 1995 have serious leaks.

Owners, often retired people, who originally paid about C$150,000 ($213,000) now face C$35,000 ($49,600) repair bills they cannot pay.

Property values there have plummeted by up to two-thirds and building consents are still less than half their previous level.

A Vancouver commission of inquiry found that the units showed signs of decay in as little as three years and buildings were being repaired twice for the same problem - which many builders say is happening in New Zealand.

It is now compulsory in Vancouver to install "drainage planes" - a gap between the cladding and timber frame allowing water to escape - in new condominiums.

Adrian Bennett, chairman of the New Zealand building industry steering group on the issue, said that the same measures might be introduced here.

If you have more information on leaking buildings, please contact us.

* Email: newsdesk@nzherald.co.nz

* Fax: 09 373 6421