Question 1

What does NatHERS stand for?

Accepted Answer

NatHERS stands for Nationwide House Energy Rating Scheme. It's the Australian Government's official system for measuring the thermal performance of homes on a 0–10 star scale, administered by the Department of Climate Change, Energy, the Environment and Water, with climate data and modelling underpinned by CSIRO.

Question 2

What is NatHERS?

Accepted Answer

NatHERS (Nationwide House Energy Rating Scheme) is Australia's national framework for rating how much heating and cooling energy a home needs. Every assessed home receives a 0–10 star rating — 0 stars meaning very poor thermal performance, 10 stars meaning the home stays comfortable year-round with virtually no active heating or cooling. NCC 2022 sets the legal minimum at 7 stars for new builds.

Question 3

Is NatHERS mandatory?

Accepted Answer

Yes for new builds and major renovations. Under the National Construction Code (NCC 2022), every new residential build in Australia must achieve a minimum 7-star NatHERS rating, and the rating must be prepared by an accredited assessor using CSIRO-approved software. Existing homes have no mandatory rating, but some states (notably the ACT) require disclosure at sale or lease.

Question 4

How is a NatHERS rating calculated?

Accepted Answer

A NatHERS rating is calculated by modelling the home in accredited software (AccuRate, FirstRate5, or BERS Pro) using inputs like climate zone, orientation, insulation R-values, window glazing, air-tightness, and shading. The software simulates a year of weather and outputs the annual heating + cooling energy demand in MJ/m²/year, which converts to the 0–10 star rating.

Question 5

What are the three NatHERS-accredited software tools?

Accepted Answer

AccuRate (developed by CSIRO), FirstRate5 (Sustainability Victoria), and BERS Pro (Energy Inspection). All three are calibrated against the same NatHERS engine, so results are interchangeable for compliance — assessors usually pick the tool they were trained on.

Star rating	Typical home	Thermal performance
0–2	Pre-1990s uninsulated	Very poor — high bills, uncomfortable
3–4	Average existing Australian home	Below standard
5–6	Pre-2022 new builds	Old minimum standard
7	NCC 2022 new build minimum	Good — modern compliance level
8	High-performance new build	Very good — low bills
9–10	Passive-house style	Excellent — barely any heating/cooling needed

What Does NatHERS Stand For? Meaning & Star Ratings Explained

What NatHERS measures

What each NatHERS star rating means

When you need a NatHERS rating

Quick facts

Curious about your home's rating?

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