My Cool Home by Hubble named among software tools in development for NatHERS for existing homes
The NatHERS Administrator has named My Cool Home by Hubble among four software tools in active development for NatHERS for existing homes assessments and the Home Energy Rating Certificate.
In its July 2026 update, the NatHERS Administrator confirmed that four software developers are making significant progress on new software tools for NatHERS existing homes assessments — and named My Cool Home by Hubble among them.
The Administrator's article states that the tools are expected to move through the accreditation process over the course of the year and be tested against the NatHERS for Existing Homes User Interface Protocol (UIP), with each developer progressing its own approach to supporting assessors and improving the user experience. The full update is published at https://www.homeenergyrating.gov.au/news/uip-development-continues-gain-pace
To be precise about status: My Cool Home is in active development in collaboration with the NatHERS Administrator. It is not yet accredited, and Hubble is one of several developers building for this pathway.
What NatHERS for existing homes is, and why it matters
NatHERS — the Nationwide House Energy Rating Scheme — has long rated new homes at design stage. The existing homes pathway extends the scheme to homes already standing, producing a Home Energy Rating Certificate prepared by an Existing Homes Assessor (EHA).
That extension is where the substance is. New homes are already regulated at construction; Australia's existing housing stock is not, and it is where the emissions, the energy bills and the heat vulnerability actually sit. A consistent national method for rating an existing home is the precondition for almost everything else — targeted retrofit programs, disclosure at sale and lease, and council and state policy that can be measured rather than assumed.
What My Cool Home does for assessors
My Cool Home is the assessor-facing tool Hubble is building for this pathway. The focus is on the parts of an existing homes assessment that take the most time on site and at the desk: capturing the dwelling, reviewing the inputs, and producing a clear, defensible certificate and set of improvement options for the householder.
Ratings under NatHERS are calculated using CSIRO's Chenath engine, the same simulation engine behind AccuRate that underpins the scheme's accredited software. Assessor accreditation itself sits with Design Matters National, and training is delivered by appointed RTOs — Hubble does not accredit assessors. We build the software.
- Structured on-site capture designed around how existing homes are actually assessed
- Clear review of inputs before a certificate is produced
- Householder-facing improvement options in plain language
Assessors: we're onboarding now
If you are undertaking NatHERS Existing Homes training, you can register your interest now and be among the first assessors onboarded to My Cool Home: https://www.mycoolhome.com.au/existing-homes
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