Buildings are responsible for 20 percent of climate change emissions by New Zealanders, a new report says.
Auckland CBD Photo: SUPPLIED
That's a huge increase from the Productivity Commission's estimate of between 2 to 5 percent.
The carbon footprint of New Zealand's buildings currently takes into account operational emissions like heating and lighting.
But the author of the Thinkstep report, Jeff Vickers, said their approach only took into account what was produced, not what was consumed.
"If you factor in the whole life cycle so taking account of production of the building products, also the operational energy and end of life, you get to a number that's 20 percent of New Zealand's total.
"It changes the game on how significant the built environment really is," he said.
New Zealand Green Building Council director Sam Archer said the construction sector needed to get up to speed with the issue.
"They need to start start thinking about 'can we build buildings better, can we be looking at the way we use concrete and steel?'," he said.
Victoria University's Senior Lecturer at the School of Architecture Nigel Isaacs described the Thinkstep report as innovative and added it shouldn't be ignored.
"The way we get to solutions is not by following the conventional path, we have to look at different ways and we need to explore, this report may be absolutely correct, it may not, but it's certainly not a report to be put on the bottom shelf, it needs to be further investigated," he said.
Mr Isaacs said there needed to be more research into greenhouse gas emission from industries like construction.
"This means things like where energy is actually used in houses, in commercial and in industrial buildings, in the rest of the infrastructure, is extremely poorly understood," he said.
Author Jeff Vickers said New Zealand manufacturers of building materials were starting to make more information available about their carbon footprint.