Australia is at a genuine inflection point when it comes to residential energy efficiency. A national scheme to rate the energy performance of existing homes is rolling out — and a growing number of banks are ready to reward homeowners who act on those ratings with discounted loans.
The NatHERS Expansion to Existing Homes
The Nationwide House Energy Rating Scheme (NatHERS) has long been the standard for rating new homes. It is now being expanded to cover existing homes too, supporting Australia’s transition to net zero emissions by 2050. From mid-2026, the scheme will be open more widely, giving homeowners access to energy rating certificates and practical guidance on the most cost-effective upgrades available for their property.
70% of Australia’s 11 million existing homes were built before the introduction of minimum energy efficiency standards — with an estimated average NatHERS rating of below 3 stars.
Even improving a home from 3 to 5 stars could reduce the energy needed for heating and cooling by around 40%, with a corresponding reduction in costs and emissions. The scale of the opportunity — and the savings — is significant.
Experts are already calling for energy assessments to become mandatory at the point of sale or lease, as they have been in countries such as Germany since 2000. The ACT is currently the only state that requires energy assessments to be published at the point of sale, but NSW is trialling voluntary disclosures from mid-2026. Energy Ministers released a national Home Energy Ratings Disclosure Framework in December 2024, setting the direction for all states and territories.
Software tools for existing home ratings can now be accredited under NatHERS, and no-cost training is being rolled out for assessors ahead of the mid-2026 Stage 2 launch. Demand is expected to build quickly.
Banks Are Already Responding
The connection between energy ratings and finance is not theoretical — it is happening now.
Bank Australia has been the most active lender in this space, offering a Clean Energy Home Loan for existing homeowners undertaking energy-efficient renovations, backed by the federal government’s Clean Energy Finance Corporation (CEFC). Demand has been so strong that the bank has had to temporarily pause new applications for its Renovate product. The loan offers a variable rate discount of around 0.7% below widely available market rates — representing over $23,000 in savings over five years on an average $680,000 mortgage.
To qualify, homeowners generally need to have completed at least three eligible energy-efficient upgrades — such as insulation, double glazing, heat pumps, or electrification — or achieved at least a one-star improvement in their Residential Efficiency Scorecard rating.
Other lenders currently active in this space include:
Commonwealth Bank: Offers existing customers a Green Loan to buy and install renewable technology at home.
- Firstmac & loans.com.au: Discounted Green Home Loans for homes meeting a 7-star NatHERS rating, plus a Solar Home Loan for homes with panels.
- Gateway Bank & Regional Australia Bank: Both customer-owned banks offer green home loan products with competitive rates for energy-efficient properties.
- Summerland Credit Union: Offers green home loan products, adding further choice for borrowers seeking sustainability-linked finance.
The Federal Government’s $1 Billion Backing
The Australian Government has allocated $1 billion to the CEFC’s Home Energy Upgrades Fund (HEUF), which partners with private lenders — including Plenti and Westpac — to provide discounted consumer finance for home retrofits such as double-glazing, insulation, heat pump water heaters, and battery storage. The fund is designed for homeowners who may not qualify for low-income grants but want to reduce upfront capital costs.
State and Territory Options
State-level financing adds further depth to the picture. The ACT’s Sustainable Household Scheme offers low-interest loans up to $15,000 for upgrades including EV chargers, induction cooktops, and ceiling insulation. Tasmania offers Energy Saver Loans up to $10,000. An increasing number of banks and financial institutions are rewarding customers with low-interest green loans for energy-efficient upgrades more broadly.
The Rating–Finance Link
What ties all of this together is the energy rating itself. Banks and lenders generally require homes to be certified against NatHERS or an equivalent scheme to qualify for green loan products. As NatHERS expands to existing homes, it is likely to become the key credential that unlocks these loan products for millions more Australians — including the 70% whose homes predate minimum energy efficiency standards.
Assessors can also provide before-and-after upgrade certificates to verify the impact of changes, and variation reports modelling the impact of proposed renovations on a home’s energy efficiency star rating — clearly demonstrating the real and measurable benefits of planned upgrades, both to homeowners and to lenders.
At NZEB Australia, we specialise in energy rating and compliance reports for residential and commercial buildings across Victoria. If you are thinking about upgrading your existing home and want to understand your options — whether for a NatHERS rating, a Residential Efficiency Scorecard assessment, or planning your path to a better star rating — get in touch with us. Contact NZEB Australia