December 16th 2021

Australian energy modelling protocols in state of flux as they adapt to driving net-zero buildings

Australian energy modelling protocols in state of flux as they adapt to driving net-zero buildings

As the industry strives towards net-zero, Australia is making a number of changes to its building regulations and rating systems to help keep it on track. To help guide our IESVE users, we’ve produced the following brief summary of the rating systems, regulations and changes…


Greenstar Buildings
Green Star Buildings sets out the criteria that must be met to deliver healthy, resilient, and positive places for people and nature. It aims to meet current and future demands on the built environment with aspirational benchmarks for addressing the key issues of the next decade: Climate action, resource efficiency, and health and wellbeing.

Greenstar Homes
Green Star Homes seeks to create highly efficient, fossil fuel free homes, powered by renewables that are healthy and resilient for all Australians. The Green Star Homes Certification provides you with the assurance from Australia’s leading authority on sustainable buildings with the Green Star Homes Trademark, which you can proudly display to your customers.

National Construction Code

The National Construction Code (NCC), maintained and published by the Australian Building Codes Board (ABCB), details the minimum necessary requirements for safety, health, amenity and sustainability in the design and construction of new buildings throughout Australia.

Part J      
Section J of the NCC (National Construction Code) deals with Energy Efficiency in all classes of buildings constructed across Australia. Changes to this are:

·         A new 2022 version

·         Incorporation of Greenstar/NABERS/JV3

·         Numbering system changes Spec 33/34 vs JVa/b etc

·         NABERS addition of other protocol Hotels/Apartments/shopping centres etc.

·         JV2/3 largely the same, no significant changes to provisions.

A DTS (Deemed to Satisfy) Solution follows a set recipe of what, when and how to do something. It uses the DTS Solutions from the NCC, which include materials, components, design factors, and construction methods that, if used, are deemed to meet the Performance Requirements. Changes include:               

·         Additional condensation provisions

·         Elemental approach change

·         NCC total R value approach changed to ADDED 

·         R-Values

·         New Part J1P2 & J1P3 performance requirements.          

·         DTS elemental (new)

·         J1V5 - new compliance pathway verification ref method similar to JV3

·         7 Star Average, 6Star Min

·         Class 1 Verification using a ref building

·         (VURB) upgrades, schedules, thermostat etc

·         New - whole-of-home annual energy use


The Nationwide House Energy Rating Scheme (NatHERS) measures a home’s energy efficiency to generate a star rating. It was first introduced in 1993.The higher the star rating, the less energy need to heat and cool the home to keep it comfortable. Changes to this scheme include:

·         H6P1 & H6P2 new requirements are now quantitative

·         7Star min stringency increase

·         Increase requirements for element perf

·         Updated climate files

·         Star bands recalibrations

·         Thermal Bridging must be included

·         HVAC load limits updated

·         4.5Star heat pumps

·         5star gas water heater

·         Ceiling fans/zone specific

Questions? Please contact with any queries and to find out more on how you can use the IESVE to meet these regulatory requirements.