Oculus Pushing For More Evidence Behind Industry Standards, As Research Finds Major Issues
Kiwi building scientists Oculus say recent research findings showing issues with a national sustainability rating tool for new builds is further evidence of many wider, underlying problems in the Kiwi building industry caused by a lack of visible scientific evidence.
Oculus says Homestar - the industry tool developed by the New Zealand Green Building Council to rate the sustainability of buildings - has instead been marketed as meaning warmer and drier houses. While the NZGBC claims homes built to a 6 Homestar rating or above will be easier and more cost effective to keep warm, healthy and more environmentally friendly than a typical new house built to building code, research carried out by Auckland University’s Rochelle Ade and Dr Michael Rehm suggests they may actually be no warmer or drier than typical new builds.
Measurements taken of the indoor temperatures in 30 social housing builds in Auckland found that the houses rated at 6 Homestar in the study spent 56 percent of the time below the World Health Organisation’s recommended minimum winter temperature of 18 degrees. Homes built to the current building code but without a 6 Homestar rating dropped below that threshold 64 percent of the time - a difference the researchers say is only minimal, meaning the tool does not go far enough to address substandard housing.
Oculus co-director Shawn McIsaac says there are misconceptions about what Homestar provides and that it may even be breaching the Fair Trading Act, as at level 6 and below it is not that dissimilar to the base building code, yet claims to be.
He says Homestar is a checklist that can be loaded to achieve a higher rating by carrying out only the more perfunctory aspects of sustainability, rather than tackling the main issues in New Zealand housing, such as heating and ventilation - with the requirements for those crucial aspects essentially the same as the inadequate stipulations of the base building code anyway.
“Housing design, particularly for the most vulnerable people who will live in social housing, should not be “only marginally better than the worst building the law permits,” he said.
Oculus co-director James Powers says the science-backed approach Oculus takes has seemed at odds with industry tools, guidance, standards, and even the building code itself, which is missing even basic scientific evidence. Ade and Rehm’s research findings, he says, weren’t unexpected.
“This is just one example of many building code requirements and standard practices that contain little to no scientific evidence to support them”.
“Until we create a culture of evidence based design, trusting the science and holding people to account for their claims, similar problems are likely to recur”.