'You've blown up your own argument': Garner grills building industry CEO on cost of housing

Duncan Garner clashed with the chief executive of the Building Industry Federation over the cost of materials on The AM Show this morning.

Bruce Kohn was on the show to discuss the cost of building in New Zealand, and claimed a report by the Productivity Commission claiming materials were cheaper overseas is incorrect.

"The supply chain's had a gutsful of hearing how expensive we are by comparison, the answer is we're not across the board," he said.

Mr Kohn said the real pain was in the land price and cited a soon to be released study showed New Zealand's costs of developing are "quite reasonable" compared to Melbourne and Sydney.

But he wasn't able to say when the study would be released or even who conducted it. Garner was not happy with the excuses.

"You have come here today to fight your corner, to say the industry's all clean and great and not charging us too much at all and you are claiming and quoting a secret report that hasn't been released and you can't tell me who's done it," Garner said.

But Mr Kohn said he could not release the results of the study on the show.

Garner later mentioned he had found very different prices in Australia when he went to build a house across the Tasman.

He was quoted $1300 per square metre for the build, but in New Zealand it would have been $2300 per square metre.

"It's not credible to say that New Zealand building products are the same price as Australia based on my experience, which was a real experience alone.

"It's not me that's lying today, I suggest it might be someone else who's misleading the country."

Mr Kohn said prices were different due to a number of factors in each market, including population, transport costs and standardisation of materials.

Garner took Mr Kohn's reasoning as acceptance it was cheaper, undermining the CEO's argument.

"It's cheaper, you've just walked around the argument and you've come on to my side. I welcome you on to my side Bruce," he said.

"You've just said that it's cheaper in Australia, you've blown up your own argument."

Mr Kohn disagreed and said you could find some items cheaper in New Zealand than Australia and vice versa.

But he said it will all be clear when the study comes out.

"When that is complete it will come out and you will have all the details and these will show you the true situation."