Building law changes will send costs spiralling, says expert

By ANNE GIBSON

Housing costs will rise by $10 billion during the next two decades as a result of proposed building code changes, says an Auckland quantity surveyor.

Geoff Bayley said he and engineer Dr Kelvin Walls made a submission to the Building Industry Authority last month on changes to building regulations and calculated the effect of introducing more treated timber and ventilated cavities to plastered houses.

The authority had calculated the rise in costs as a result of changes to building laws which seek to redress the leaky building crisis, Bayley said.

Authority public affairs manager Mike Noon said more than 300 submissions were received on the proposed changes and all were being reviewed by the expert working groups and the authority.

The cost of the proposed changes had been calculated by the New Zealand Institute of Economic Research.

"It is proposed that the cost benefit report by the NZIER will be updated as a result of any new information received through the submission process," Noon said.

Alterations to the amount of treated timber used to build houses and changes to house construction were only proposed and no decisions had been made, Noon said.

"So it's too early to calculate what the costs might be."

The authority is due to meet this month. Its board will consider submissions on the changes and is expected to bring in the changes in the next few months.

But Bayley fears the result of the changes will be a huge price rise which will cost the country dearly.

"The figures have been significantly underestimated by the Institute of Economic Research, which calculated the costs at between $4000 and $5000 a house, but these are wrong," Bayley said.

Instead, house costs will rise by up to $20,000 a house if the authority implements the changes, he said.

Bayley said the leaky building crisis could be fixed with a focus on better workmanship, good design and maintenance of houses which would keep costs down and address the real issues.

Bayley said the institute had calculated 500,000 houses would go up in the next 25 years. He has multiplied $20,000 by the number of houses which the institute estimated would be built in the next two decades.

Bayley said the institute had miscalculated the amount of treated timber needed to build a house. It had calculated the amount at 3.8 cu m, when the figure should be 20.2 cu m.

"They are only 600 per cent light on the calculations," he said.

Flexible flashings around windows, recommended by the Building Industry Authority's working group, would add $2500 to the total house cost and were unnecessary.