What Is a NatHERS Energy Rating?
Learn what NatHERS energy ratings are, who administers the scheme, and why they matter for Australian homeowners building or renovating.
Understanding the Nationwide House Energy Rating Scheme
The Nationwide House Energy Rating Scheme (NatHERS) is Australia's system for rating the energy efficiency of residential buildings. Administered by the Australian Government through the Department of Climate Change, Energy, the Environment and Water (DCCEEW), NatHERS provides a standardised way to measure how much energy a home needs to stay comfortable throughout the year.
At its core, NatHERS measures the thermal performance of a home's building envelope — that is, the roof, walls, floor, windows and doors that separate the inside from the outside. The rating tells you how much heating and cooling energy the home will need to maintain a comfortable temperature, expressed as a star rating from 0 to 10.
How the Star Rating Scale Works
A home rated at 0 stars performs no better than a tent, offering almost no protection from outside temperatures. A 10-star rated home requires virtually no artificial heating or cooling to remain comfortable year-round. Most new homes in Australia achieve ratings between 6 and 8 stars.
Under the National Construction Code (NCC) 2022, the minimum energy efficiency standard for new homes across most of Australia is 7 stars, up from the previous requirement of 6 stars. This change reflects Australia's commitment to reducing household energy consumption and carbon emissions.
When Is a NatHERS Rating Required?
A NatHERS assessment is required in most circumstances when you are:
- Building a new home
- Undertaking major renovations that affect the building envelope
- Adding an extension to an existing dwelling
- Converting a building to residential use
The specific triggers vary slightly between states and territories, but all jurisdictions in Australia reference the NCC, which in turn references NatHERS as one of the approved pathways for demonstrating energy efficiency compliance.
Who Administers NatHERS?
The NatHERS scheme is overseen by the Australian Government, with the DCCEEW managing the framework, accrediting software tools, and setting the technical standards. However, the day-to-day accreditation of individual assessors is handled by three Accrediting Authority Organisations (AAOs):
- Design Matters National (DMN) — formerly the Association of Building Sustainability Assessors Victorian chapter
- ABSA (Australian Building Sustainability Association) — also known as BDAA (Building Designers Association of Australia) in some states
- HERA (House Energy Rating Association) — a newer AAO providing an additional accreditation pathway
Each AAO maintains a register of accredited assessors who have demonstrated the necessary competency to perform NatHERS assessments using the accredited software tools.
A Brief History of NatHERS
NatHERS has its roots in research conducted by the CSIRO during the 1990s. The scheme was formally established in 1993, making it one of the longest-running residential energy rating systems in the world. Initially voluntary, NatHERS became increasingly important as states and territories began mandating minimum energy performance standards for new homes.
Key milestones in the scheme's history include:
- 1993 — NatHERS formally established
- 2003 — Most states adopt a minimum 4-star requirement
- 2006 — National minimum raised to 5 stars
- 2010 — National minimum raised to 6 stars
- 2022 — NCC 2022 raises the minimum to 7 stars and introduces Whole of Home provisions
Why NatHERS Matters for Homeowners
For homeowners, a NatHERS rating provides several important benefits:
- Lower energy bills — A higher-rated home needs less heating and cooling, which translates directly to reduced energy costs
- Greater comfort — Well-designed thermal envelopes maintain more stable indoor temperatures, reducing draughts and hot spots
- Higher property value — Energy-efficient homes are increasingly valued in the property market, with some studies showing a premium of 5-10% for higher-rated homes
- Reduced environmental impact — Less energy consumption means fewer greenhouse gas emissions from your home
If you are planning to build or renovate, understanding your NatHERS rating is an essential step in creating a comfortable, cost-effective, and environmentally responsible home. You can find a qualified assessor to help you through the process.
Getting Started
The first step in obtaining a NatHERS rating is engaging an accredited assessor. They will model your home using one of the accredited software tools and provide a detailed report showing your star rating and recommendations for improvement. To learn more about what the assessment involves, read our guide on the NatHERS assessment process.