Around 70 per cent of Australia’s 11 million homes were built before minimum energy efficiency standards were introduced, with these homes estimated to have an average energy rating of below three stars. This represents a significant opportunity to improve household comfort, reduce energy bills and lower emissions across Australia’s existing housing stock.
To help address this challenge, the Nationwide House Energy Rating Scheme (NatHERS) has expanded beyond new homes to include existing homes. The official launch of NatHERS for Existing Homes Stage 2 on 1 July 2026 marks a major milestone, making a nationally consistent home energy rating system available more broadly and supporting homeowners, buyers and industry professionals with trusted information to guide energy efficiency improvements.
Stage 2 isn’t just a technical update. It’s the point where existing home energy ratings moved from a limited, trial-based rollout into something more accessible — for the assessors who deliver the ratings and the homeowners who receive them. It also comes with a new consumer-facing brand, a new website, and some significant changes to how accreditation and assessments work.
Here’s what’s changed and how those changes affect assessors and homeowners.
Home Energy Rating Assessments Explained: A Quick Recap
If you’re new to this, here’s the short version.
A Home Energy Rating assessment is a professional evaluation of how a property performs thermally — how well it holds heat in winter and stays cool in summer, and how efficiently its fixed appliances and systems use energy. An accredited assessor visits the property, collects data on its construction, insulation, glazing, and appliances, and uses NatHERS-approved software to generate a Home Energy Rating Certificate. That certificate includes a thermal star rating (0–10) plus a Home Energy Rating score (0–100), along with practical upgrade recommendations.
This is different from a Home Energy Rating (NatHERS) new homes assessment which has existed for decades and models a dwelling’s performance at the design stage, before it’s built. Existing homes assessments work with what’s already there — real insulation, real windows, real appliances — which makes the assessment process, the training, and the administrative model different.
If you’ve heard of the Residential Efficiency Scorecard, Home Energy Rating for existing homes is effectively its national successor. Scorecard, which ran in Victoria and then nationally from 2021, closed on 23 June 2026.
From Stage 1 to Stage 2: What’s Actually Changed
Stage 1 launched in mid-2025 as a deliberately limited release. A first-generation tool and assessment method, was made available to a small, targeted pool of assessors (largely NatHERS new homes assessors, Scorecard assessors, and ACT Energy Efficiency Rating assessors) while the program scaled up and learned from real-world delivery. Alongside it, a national field trial ran from 2024 into early 2026 in partnership with CSIRO and four major banks, delivering more than 1,000 free assessments to test the model across different climates and dwelling types. It confirmed the approach was fit for purpose and ready for wider rollout.
Stage 2, which began on 1 July 2026, is that wider rollout. It brings:
- A second-generation assessment tool, method, and process, refined using everything learned during Stage 1 and the national trial
- Accreditation and training open to all interested assessors, not just the earlier target cohorts
- A refreshed Home Energy Rating Certificate
- A new “Find an Assessor” search tool, letting homeowners enter an address to locate an accredited assessor servicing their area
- A new consumer-facing brand and website, Home Energy Rating (homeenergyrating.gov.au), sitting alongside the NatHERS brand, which continues to support industry, governance, and regulatory functions
Timeline at a Glance
| Milestone | Date |
| Government announces funding to expand NatHERS to existing homes | 2023 |
| National field trial (with CSIRO and four major banks) | 2024 – early 2026 |
| Stage 1 launches | Mid-2025 |
| NSW Home Energy Ratings Disclosure Framework pilot | Late 2025 |
| Scorecard accreditation closed | 30 April 2026 |
| Residential Efficiency Scorecard program closes | 23 June 2026 |
| Stage 2 and the launch of the Home Energy Rating brand and website | 1 July 2026 |
What Stage 2 Means for NatHERS Assessors
For assessors — whether you’re already accredited, mid-training, or considering the profession — Stage 2 changes the practical path forward in a few important ways.
Accreditation is now open to everyone. Where Stage 1 restricted training and accreditation to specific industry cohorts, now new entrants, career changers, and existing building or sustainability professionals can pursue training and apply for accreditation as a Home Energy Rating assessor for existing homes.
The training pathway runs through a Certificate IV. Prospective assessors typically need relevant units from the Certificate IV in Home Energy Efficiency and Sustainability, the specific NatHERS Existing Homes assessment unit, and approved software training.
If you’re already accredited as a NatHERS new homes assessor through any NatHERS Assessor Accrediting Organisation (AAO), your pathway to assessing existing homes may be streamlined, depending on your existing qualifications and experience. Existing homes accreditation is currently available through Design Matters National (DMN), allowing eligible assessors to expand their scope of practice by meeting the additional accreditation requirements.
Financial support has been extended. Accreditation fees are fully subsidised for currently accredited existing homes assessors and industry transition trainees, until at least 30 June 2027. On top of that, new trainees seeking accreditation from the Stage 2 release are eligible for a share of 150 accreditation and membership subsidy places — reducing a barrier to entry for new assessors. Conditions and eligibility criteria apply, so it’s worth checking your specific situation before assuming you qualify.
The role itself differs from new homes assessments in several important ways. Existing homes assessors work directly with homeowners and conduct on-site inspections, rather than assessing architectural plans from a desk. That means more face-to-face client interaction, more time spent gathering information on site, and applying professional judgement within the established NatHERS assessment and accreditation framework.
If you’re considering whether now is the right time to get involved, Transformed is one of only two Registered Training Organisations appointed to deliver Home Energy Rating for Existing Homes training, alongside the Certificate IV in Home Energy Efficiency and Sustainability that underpins the pathway. You can learn more about that appointment and the training pathway in our earlier blog, Transformed Appointed to Deliver NatHERS Existing Homes Assessor Training.
What Stage 2 Means for Homeowners
If you own a home and you’ve heard about NatHERS ratings mostly in the context of new builds, here’s what Stage 2 changes for you.
Assessments are becoming more accessible. Previously, existing homes assessments were only available to a small number of households as part of the trial and scale-up. With Stage 2 now live, the new Find an Assessor tool makes it straightforward to locate an accredited assessor who services your area.
Assessments are not yet mandatory. A Home Energy Rating assessment for existing homes is voluntary at this stage — there’s no current requirement to get one before selling, leasing, or renovating a property (the ACT is an exception, it has operated its own mandatory Energy Efficiency Rating disclosure scheme since 1995). That said, the direction of travel is toward greater transparency: Version 2 of the national Home Energy Ratings Disclosure Framework sets out how ratings could eventually be provided to households at the point of sale or lease. A cost-benefit analysis conducted alongside it found a net economic benefit to households who act on their rating results.
A Home Energy Rating for Existing Homes assessment provides valuable insights into how a home’s energy performance can be improved. It identifies where a home is losing comfort and energy, helping homeowners prioritise upgrades that can improve year-round comfort, reduce energy use and potentially lower household running costs.
The assessment can also unlock additional benefits. A growing number of lenders now offer discounted “green” home loans, with some using a Home Energy Rating for Existing Homes assessment as part of their eligibility criteria. As the scheme continues to expand, energy ratings are expected to play an increasingly important role in supporting informed property, renovation and financing decisions.
What to expect from the process. An assessor visits the property, collects data on its construction and systems, and produces a certificate with a thermal star rating, and a Home Energy Rating score. The certificate also includes upgrade recommendations. Having building plans, insulation records, or appliance details on hand can help things move faster, though they’re not essential — the assessor will collect what’s needed on-site.
The Bigger Picture: Disclosure and Where This Is Heading
The most consequential long-term piece of this expansion is the Home Energy Ratings Disclosure Framework — a national approach, agreed by Australian governments, for how ratings could eventually be provided to households at the point of sale or lease. A pilot of the framework ran in NSW, and the resulting cost-benefit analysis found meaningful net benefit for households that act on their ratings, along with a case for mandatory disclosure at point of sale for houses and apartments, and potentially point of lease as well.
While Home Energy Ratings for Existing Homes are not currently mandatory, interest in home energy performance is continuing to grow. The launch of NatHERS Existing Homes Stage 2 provides a nationally consistent framework for assessing existing homes, supported by assessor accreditation, approved software and consumer-focused resources.
State governments are also beginning to promote the value of home energy ratings. For example, the NSW Government recently launched its Home Energy Ratings initiative to help homeowners better understand their home’s energy performance and identify opportunities to improve comfort and reduce energy costs.
These developments signal growing recognition of the profession and increasing opportunities as awareness of home energy performance continues to build. For homeowners, obtaining an energy rating provides trusted, evidence-based information that can support renovation planning, energy efficiency improvements and more informed property decisions.
Frequently Asked Questions
Is a Home Energy Rating assessment for existing homes mandatory?
No. It remains voluntary. A disclosure framework has been developed and piloted, but no state or territory currently requires a rating at the point of sale or lease, aside from the ACT.
How is Stage 2 different from Stage 1?
Stage 1 was a limited release to a small pool of target assessors and households, used to test and refine the model. Stage 2 is the full-scale rollout: open accreditation, an upgraded second-generation tool, a refreshed certificate, and a new consumer website and brand (Home Energy Rating).
Can I still get a Residential Efficiency Scorecard assessment?
No. Scorecard closed on 23 June 2026.
How do I become a Home Energy Rating assessor for existing homes?
You will need to complete relevant units of the Certificate IV in Home Energy Efficiency and Sustainability, the NatHERS existing homes assessment unit, and approved software training. There is also streamlined training for current assessors. Free accreditation for membership for existing homes is also available.
Are Home Energy Rating assessments for existing homes available in my state?
Currently, there are accredited assessors in all jurisdictions (except for the Northern Territory). Use the Find an Assessor tool on the Home Energy Rating website to check for assessors who service your local area.
Start Your Career as a Home Energy Rating Assessor
Whichever side of the assessment you’re on, Stage 2 is worth paying attention to. If you’re a homeowner, you can now get an assessment and clear, practical advice for improving your home’s comfort and running costs. If you’re considering a career as an assessor, accreditation is open, training pathways are established, and financial support is available.
Read more about Transformed’s Certificate IV in Home Energy Efficiency and Sustainability which is the foundational qualification for accreditation.
Get in touch with our team to talk through your pathway, eligibility for subsidies, and how to get started.