Building industry cuts corners say investigators

By SIMON COLLINS


A taskforce of professional engineers has upheld a claim that some New Zealand building practices would endanger lives and buildings in a big earthquake.

The high-powered taskforce says that in the past 20 years, standards in structural engineering have declined, and it condemns "the current loose regulatory environment".

Another report commissioned by the Building Industry Authority has also called for action against the use of precast hollow-core floors in high-rise buildings in areas of earthquake risk.

The authority has accepted most of the criticisms and has started a pilot survey in Christchurch to test precast hollow-core floors. The survey will be extended to the rest of the country if the engineers' concerns are confirmed.

The two reports, one by a taskforce of the Institution of Professional Engineers (Ipenz) and the other by engineers Sinclair Knight Merz, were issued last night in response to a damning open letter by Auckland structural engineer John Scarry, reported in the Herald in March.

Mr Scarry cited 26 cases of bad practice and said many precast concrete high-rise blocks built since 1994 would collapse in a big earthquake.

The Ipenz report finds that Mr Scarry "raised valid concerns throughout his open letter", although "the extent and severity of problems were lesser than may have been implied by the way his open letter was worded".

The taskforce says current practices that would endanger lives and properties include:

* Precast slender panels being erected at height-to-slenderness ratios that breach standards.

* Precast hollow-core flooring, which is still being researched. Recent tests show it performs worse than thought. * The use of 500E-grade reinforcing steel, which replaced alternatives on the market before the concerns of respected academics were addressed.

* Poor standards of construction, and failure to retain design engineers to supervise.

The taskforce said deregulation of the industry had allowed manufacturers to pay for the development of standards to justify their own products.

"This could lead to the development of standards that were not in the interests of the safety/financial security of the public."

It called for the authority to take back control of all standards and codes of practice, paid for from a levy on building-consent applications.

The taskforce confirmed a claim by Mr Scarry that professional engineers often have nothing more to do with a building after it gets a building consent, leaving supervision to "less competent people".

The taskforce urged the authority to audit a sample of 50 completed buildings a year to check on the local body inspectors.

It also called "as a matter of urgency" for the authority to review the use of grade 500E reinforcing steel, precast hollow-core floors and precast slender wall panels with height-to-thickness ratios above 30.

Mr Scarry said the report vindicated his concerns. He called for raising the building industry levy from around $3 million a year at present to 1 per cent of the value of new building - around $80 million a year.

"I think the levy needs to be expanded to back up not only the development of standards and codes of practice, but more importantly, for actual testing and to support the intellectual bodies that can support the universities in preparing guidelines," he said.

Private building certifiers should be abolished because their competition forced local body building inspectors to cut corners.

"You can't have competition in a regulatory environment. You can't have two customs services at the border."

Outgoing authority chief executive Richard Martin said it was already reviewing grade 500E steel and precast hollow-core floors and was considering the taskforce recommendation on thin precast walls.

But the proposal to audit 50 buildings to check on local bodies was against the whole thrust of the new Building Bill.