NatHERS Existing Homes Stage 2: What Changed for Assessors in 2026

If you're accredited for new homes and you've been watching the existing-homes rollout from the sidelines, 1 July 2026 is the date that changed your answer. Stage 2 of NatHERS for Existing Homes opened accreditation and training to every interested assessor — not just the earlier trial cohorts — and if you're already accredited for new homes, adding existing homes doesn't cost you an extra accreditation fee.

Here's exactly what changed, what it costs, and what the refreshed certificate now looks like.

What actually changed on 1 July 2026

Stage 1 ran as a limited rollout, built around specific trial cohorts while the scheme worked out the assessment method against real housing stock. Stage 2 is the full-scale version: accreditation and training are now open to all interested assessors, running on a second-generation assessment tool, method and process that was refined using everything learned during Stage 1 and the national field trial.

If you've been waiting for the tool to stabilise before committing time to this, that's the actual signal here — Stage 2 isn't a beta any more.

The cross-accreditation pathway, if you're already accredited for new homes

This is the detail that matters most if you're in Dale's position — accredited for new homes, watching existing-homes demand build. New-homes assessors can be accredited for existing homes at no additional accreditation cost. You'll still pay your usual membership fee to your AAO, but the accreditation step itself doesn't carry a second price tag on top of what you already hold.

What it actually requires: the relevant units from the Certificate IV in Home Energy Efficiency and Sustainability (CPP41126), the specific NatHERS Existing Homes assessment unit, and approved software training. Design Matters National (DMN) is currently offering existing-homes accreditation; check whether your existing AAO offers the same pathway before assuming you need to switch. If you're mapping out the Cert IV side of this from scratch rather than topping up an existing accreditation, we've covered the cost and timeline for that separately.

Money on the table — and a real deadline

Accreditation fees are fully subsidised for currently accredited existing-homes assessors and industry transition trainees, and that subsidy runs until at least 30 June 2027. Separately, there are 150 subsidised places specifically for brand-new trainees entering at Stage 2 — a limited number, not an open-ended offer, so it's worth acting on rather than filing away for later.

What's actually in the refreshed certificate now

The Home Energy Rating certificate assessors produce under Stage 2 carries two numbers, not one: a thermal shell star rating out of 10 (reflecting how the building envelope itself performs) and a separate Home Energy Rating score out of 100 that also factors in the home's actual appliances, hot water and any solar or battery — plus a list of upgrade recommendations. If you've only ever produced new-homes certificates, this second, appliance-inclusive number is the main structural difference to get used to.

How homeowners will actually find you

The consumer-facing side of the scheme has rebranded to Home Energy Rating (homeenergyrating.gov.au), and it now includes a "Find an Assessor" search tool that lets homeowners search by location. That's the official channel; it sits alongside — not instead of — however you already generate work through referrals, your AAO listing, or a platform like MyCool Home that routes homeowner demand directly to accredited assessors.

Our take

If you're a new-homes assessor who's been waiting to see whether existing homes was worth the move, Stage 2 removes the two reasons to keep waiting: the tool is now the settled, second-generation version, and adding the accreditation doesn't cost you a second fee on top of what you already hold. The subsidy windows are real but time-limited, which makes this a better year to act than a future one.

Frequently asked questions

When did NatHERS Existing Homes Stage 2 actually launch?

1 July 2026, moving the scheme from a limited Stage 1 rollout to accreditation and training open to all interested assessors. Source: Transformed.

If I'm already accredited for new homes, does adding existing homes cost extra?

No additional accreditation cost — you'll still pay your usual AAO membership fee, but the existing-homes accreditation itself doesn't carry a second fee on top of your new-homes accreditation. Source: Transformed.

Are accreditation fees actually subsidised right now?

Yes — fully subsidised for currently accredited existing-homes assessors and transition trainees until at least 30 June 2027, with a separate pool of 150 subsidised places for brand-new trainees entering at Stage 2. Source: Transformed.

What's different about the certificate under Stage 2?

It carries a thermal shell star rating out of 10 alongside a separate Home Energy Rating score out of 100 that also accounts for actual appliances, hot water and any solar or battery, plus upgrade recommendations — not just the single star rating a new-homes certificate produces.

How do homeowners actually find an accredited existing-homes assessor now?

Through the rebranded consumer site, Home Energy Rating (homeenergyrating.gov.au), which includes a "Find an Assessor" search tool by location — on top of whatever referral or platform channels you already use. Source: Transformed.

Accredited for Existing Homes? MyCool Home brings the homeowners.

Homeowner demand is the part the accreditation pathway doesn't solve for you. Register your interest and get matched with homeowners who already have a ComfortScore and are ready for a formal assessment.