Maybe with Western Australia finally switching to the latest version of the National Construction Code next month there will be no more homes built with seriously poor energy standards. Maybe not. Here’s what we heard from an architect, the state government, the UDIA WA and a source who prefers to remain anonymous.
New homes in Western Australia are often built below the minimum energy performance rating for Australian dwellings, industry sources have told The Fifth Estate.
While WA adheres to the minimum six-star NatHERS requirement like most other states and territories, the standard can be subject to a deemed to satisfy method and this gives rise to a tendency to exploit loopholes in the system. The result is a glut of homes with an equivalent energy rating as low as two stars NatHERS equivalent.
The misuse of the alternative solution to tick off energy performance, called the verification using a reference building (VURB) method, commonly results in the dwelling not requiring a NatHERS star rating.
Western Australian eco-effective architect Sid Thoo says that by using this method, it can seem possible to deliver a compliant building with no cavity wall insulation nor thermally efficient windows.
While the reference building method has been found to be misused in other parts of Australia, Thoo says it’s unfortunately common in his home state.
He says the problem stems from WA’s home building market that is dominated by just a few highly influential building companies that would prefer to continue delivering cavity brick houses with minimal insulation even if it leads to higher energy bills for their customers.
“These builders are resistant to change and would prefer to continue with business as usual,” Thoo says. “They appear to be more focused on meeting a price point and getting contracts signed, because the volume housing market is highly competitive.”
This is coupled by the existence of a few rogue energy assessors that are “more interested in turning a buck rather than ensuring customers get a well performing home.
“The builders don’t ask too many questions as long as the assessor is willing to sign off on the design.”
It’s hard to know exactly how many homes are built this way given that the agency responsible for managing compliance to building regulation, the Department of Mines, Industry Regulation and Safety (DMIRS), does not hold data on energy efficiency assessments for buildings.
Using data from the CSIRO, around 80 per cent of homes in 2016-2018 built in WA are completed using either VURB or Non Accredited Energy Assessors. That only leaves 20 per cent that use the NatHERS pathway.
The VURB method
The verification using a reference building (VURB) compliance pathway was intended as a legitimate alternative to the energy rating method. It relies on creation of a reference building that has been modelled to meet the elemental “deemed to satisfy” provisions of the building code, with a design green lighted when theoretical energy use for the proposed building is either the same or lower than the benchmark energy heating/cooling loads of the reference building.
The problem is that it’s possible to mock up a deliberately inefficient reference building that makes the proposed design appear “better” by comparison.
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In the 2019 update of the National Construction Code, the Australian Building Codes Board effectively eradicated these loopholes. The update was adopted by all states and territories in 2019 except WA, which extended the transition period to allow the prior version to be used up until 1 May 2021.
Thoo remains concerned that problem assessors are looking for other weaknesses in the system so that builders don’t need to improve the thermal performance of their buildings.
Another industry source contacted by The Fifth Estate indicates that performance solutions will now likely replace VURB as an ongoing loophole in WA to provide homes well below the minimum 6 star standard.
What’s being done?
A spokesperson from DMIRS, the agency responsible for educating industry on these matters, says the department is communicating new energy efficiency requirements and regulation to builders, developers and energy assessors.
The department is also investigating strategies to raise public awareness and understanding of this issue.
According to the industry source, consumers need to be educated about these issues so that they can demand better from the industry. The source claims that consumers are not often aware that their home has been deemed compliant on energy efficiency using the VURB method.
There also seems to be a misconception in the market that every house has to be a minimum of 6 stars. With larger brands resisting change, consumer awareness is key.
The UDIA calls for balancing innovation with increased costs for customers
The WA branch of the Urban Development Institute of Australia (UDIA), an industry association for the development industry, welcomes the upcoming update to the NCC that aims to achieve better energy efficiency in the building stock.
“UDIA supports the objectives under the NCC of building more energy efficient residential stock and establishing a clear trajectory in the evolution of the NCC that gives industry certainty, transparency and the opportunity to adjust,” UDIA WA chief executive officer Tanya Steinbeck told The Fifth Estate.
Steinbeck also says that that it’s important to balance any type of industry innovation with the extra capital costs for customers.
“We do believe it is important to provide a balanced framework that recognises the imperatives of energy efficiency alongside the industry’s capacity for innovation and the premium placed on costs by homebuyers.”