Study shows low-bill low-carbon homes are an affordable proposition
Willow Aliento | 23 March 2017
Housing lobby groups are always quick to claim that more sustainable housing harms affordability. But developers of The Cape in regional Victoria, say their project proves they are wrong.
Additional costs are marginal, at most, with short term paybacks for owners.
Analysis by the Alternative Technology Association for developer Brendan Condon showed that the price premium to deliver an 8.2 Star NatHERS home that has been completed and is now lived in was just over $5000.
ATA energy projects and policy manager Damien Moyse said that at this figure, the sustainability features will pay for themselves very quickly.
The ATA has has undertaken economic modelling, business case and energy analysis for the project, which will comprise about 220 all-electric homes with rooftop solar power and energy ratings of 7.5 stars or higher built on former farmland on the Bass Coast completed over the next seven years.
Moyse says the aim of the modelling and analysis was to quantify the benefit achieved by the designers, builders and energy experts.
The 8.2 star home has no cooling load and a very low heating load.
The hot water is supplied by a heat pump, which can be powered throughout the day by the rooftop solar PV system.
In total, the home’s running costs are expected to be as low as around $500 a year. This compares to the average Victorian household paying around $2500 to $3000 per year in stationary energy costs for electricity and mains gas.
Brendan Condon told The Fifth Estate his development has “designed out gas” in terms of stationary power connections for the homes.
Moyse says there is no economic case in Victoria to connect to mains gas and that the same is true for any house anywhere in Australia.
“For low-carbon, low-bills homes, the future is all-electric homes,” Moyse says.
With the right size of solar PV, any new home can achieve low carbon and low bills, he says.
Currently, 80 to 85 per cent of Victorian homes are connected to mains gas, the highest percentage of any state in Australia.
This means all those households are paying higher energy costs than they would otherwise need to.
“If you are connected to two networks, you have around a $700 fixed price for stationary energy even before you use a megajoule.”
Moyse says the ATA recently did a survey ofaround 1000 people and found there are people interested in unplugging their homes from mains gas.
Interestingly, the Facebook group, “My Efficient Electric home” is growing.
“We did a report in 2014 that showed it is not economic for new homes to connect to mains gas,” Moyse says.
“Residential gas volumes have been going down and have been doing so for a few years now.
“The future’s pretty clear – it will not be too long before it will cost $1000 [in supply charges] just to be connected to both mains gas and electricity.”
Moyse says the majority of volume builders are simply concerned about “least cost to deliver” and do not care about the home’s running costs.
This is despite the fact the “economics are so compelling” for efficient homes.
Moyse says s other developers are requesting that the ATA do similar studies for their projects. One of them, Sociable Weaver, is aiming to deliver a 10 Star home at The Cape.
Moyse says that on first glance, this could mean a significantly greater cost premium..
This home will have no heating or cooling load.
“The economics might not be as good,” he says, beyond 8 stars there could be diminishing returns.
It could be that 8 Stars plus renewable energy from solar is the best outcome in terms of the business case and the sustainability case.