SPR was commissioned by Climateworks Centre to undertake detailed and comprehensive modelling of the potential for, and cost-effectiveness of, retrofitting existing Australian dwellings. The modelling resolved a range of upgrades from levels as low as 1.5 NatHERS stars right up to zero net energy across all dwelling classes for all major housing archetypes in Australia, suburb-by-suburb, for all states and territories.
This major applied research project represented a first-of-a-kind in Australia. SPR’s roles were, first, to determine the precise nature of the dominant dwelling ‘archetypes’ (typical designs, sizes, and construction material and methods) separately for houses, townhouses and apartments across Australia, both nationally and for all ~2,450 SA2 regions , working primarily with CSIRO data. Second, we estimated the numbers and shares of each of the dominant dwelling archetypes in every SA2, matching CSIRO and Australia Bureau of Statistics data. Third, drawing on CSIRO simulation modelling,we undertook detailed impact and private/societal benefit cost analysis for three levels of upgrades to thermal shells (base ~1.5 – 2 stars, up to ~9stars) and for upgrading whole-of-home performance to net zero energy and emissions, separately for each dwelling archetype. This research demonstrates that it is highly cost-effective for the majority of existing dwellings in Australia to be upgraded to zero net energy/emissions – with the key exception being those with poor solar access. Doing so would save at least $3,000 per year in energy bills, on average, with net cost savings(energy bill savings less upgrade financing costs) from Year 1 in most cases. At the same time, these upgrades would materially reduce greenhouse gas emissions, climate/heatwave vulnerability risk, and electricity peak demand and infrastructure costs.