NatHERS Star Issue 14 - August 2022

Mid-year review

Read about the latest on NatHERS preparations to support the expected updates to the National Construction Code (NCC) 2022 including the recent announcement that the Australian Building Codes Board (ABCB) will recommend that Building Ministers delay the start date to 1 October 2022.

There is also a reminder about testing out the beta tools which are now all online or available on request. 

We also feature an important article for NatHERS assessors on getting window openability percentages right, and an update on the successful launch of the popular resource Your Home.  

Please keep an eye on your inbox in the build up to the NCC launch, as we will continue to share relevant technical updates with you via this newsletter, and on our website

We will also keep you posted about a planned series of public webinars and other events, along with important technical materials as they are finalised and published.   

Happy reading! 

The NatHERS Team

NCC 2022 update

Recognising the tight timeframes associated with Building Ministers not meeting until late August, and the complexity of other issues currently affecting the construction sector, the ABCB will recommend to Building Ministers that the publication date for NCC 2022 be further delayed from 1 September 2022, to be not earlier than 1 October 2022.

During this time the NatHERS team continues work on tools and material to support compliance with the proposed increased energy efficiency requirements in the NCC. The focus is on delivering the benchmark software tool (AccuRate) to include the proposed NCC changes. 

Updates to the Software Accreditation Protocol (SAP) and the development of guidelines and training for assessors are also underway. All material to support commercial tool providers to develop accredited NatHERS tools incorporating the proposed NCC changes will be available by 1 September 2022. 

Building Ministers are scheduled to meet in late August to make a final decision on the proposed residential energy efficiency changes for NCC 2022. Following this meeting a communique will be released and we will inform you of the outcomes.

Test out beta software tools

Beta versions of NatHERS software tools are now available in preparation for NCC 2022. New climate files, updated star bands and proposed heating and cooling load limits have been incorporated into the beta versions of NatHERS software tools. Users can download the tools to try out some of the new features and explore the star rating impacts on specific types of dwellings. 

Visit the website to test out the beta software tools now! 

Note the Beta version of AccuRate is no longer available ahead of commercial release on 1 September.

Whole of Home benchmark tool

CSIRO is incorporating enhancements identified through the NatHERS and NCC 2022 consultation processes into the NatHERS Whole of Home benchmark tool ahead of release. The work program is focused on delivering a tool ready for the proposed 2022 NCC changes, including producing the new Whole of Home Performance Rating. Additional development will be conducted to expand the available technologies in the tool over the coming months. 

Users wishing to understand their Whole of Home design requirements for NCC 2022 may use either the ‘Class 1 and 2 whole-of-home provisions’ calculator provided by the ABCB or Sustainability Victoria’s FirstRate5 Whole of Home Pilot Tool.

Note that at this stage both these tools will provide an indication of compliant solutions, but may not be exact until after final decisions on stringency are made. When launched, assessors will be able to use accredited NatHERS tools to optimise their designs and appliances for a holistic solution, and take advantage of the wider array of technology available through NatHERS.

How to correctly assess window openability

 Assessor Accrediting Organisations (AAOs) and certifiers are being encouraged to check ratings for window openability percentage errors. Window openability is often misunderstood in NatHERS ratings, and as a consequence, some assessors are modelling them incorrectly. But there is one simple rule of thumb for NatHERS assessors – always refer to the NatHERS Technical Note

Air movement vs ventilation

NatHERS software tools assess heat escaping and breezes entering through a window’s opening. This is used to help model annual cooling loads. It is very different to the National NCC ventilation requirements which consider air quality and condensation as health and safety issues. 

For accurate NatHERS assessments the percentages listed in Table 5: Provisional window opening percentages of the Technical Note must always be used. 

Restricted window openings for upper storey windows are also causing confusion for some NatHERS assessors. Just to reiterate, the percentages in Table 5: Provisional window opening percentages for restricted window openings must be used, not the ventilation opening percentages referenced in the NCC’s Protection of openable windows Advisory Note

Please note that Clause and the percentage table in Part 3.12.4 of the ABCB’s Advisory Note, do not apply to the NatHERS pathway for satisfying the NCC energy efficiency requirements.  

So to ensure you don’t get pulled up by your AAO or certifier for using incorrect window opening percentages in your NatHERS rating, remember to always follow the requirements of the NatHERS Technical Note. 

Coming soon: Whole of Home Training

We are developing three new Continuing Professional Development (CPD) units to get assessors ready for the introduction of NatHERS Whole of Home assessments. The units will cover; an overview of the changes, the minimum requirements for a Whole of Home assessment and tool specific training. 

Watch this space for further developments and for further information on Whole of Home changes please refer to the Frequently Asked Questions page. 

In other news

New department, new Ministers! 

From 1 July 2022, the climate change and energy functions that previously sat with the Department of Industry, Science, Energy and Resources (DISER) have transferred to the new Department of Climate Change, Energy, the Environment and Water (DCCEEW). The Hon Chris Bowen MP is the Minister for Climate Change and Energy alongside Senator the Hon Jenny McAllister as Assistant Minister. 

Visit the new Department of Climate Change, Energy, the Environment and Water website to learn more about its responsibilities and structure.

Your Home performing well

The new edition of Your Home – Australia’s Guide to Environmentally Sustainable Homes – is getting the sustainability message across.  Over 3,100 copies of the book have been sold and the online resource has been accessed more than 671,000 times since its launch on 28 September last year. Your Home helps NatHERS assessors, builders, designers and other practitioners communicate to clients why energy efficiency is important and how to do it well. 

The sixth edition includes new information to support the transition to NCC 2022, including content on ventilation and airtightness, building in bushfire prone areas, batteries, solar PV, appliances and much more.


Go to to read online or buy the book.  

Sustainable House Day 2022

Renew are doing things differently this Sustainable House Day (SHD). The event series will kick off in October 2022 with an in-depth look at Sustainable Design 101, Bushfire Resilient Design and Sustainability for Renters. The traditional SHD with open homes across the country will take place in

March/April 2023.

The NatHERS team will be presenting webinars on sustainable design and building, and discussing the changes to the National Construction Code and introduction of Whole of Home assessments.  

Visit the Sustainable House Day website  for more information and to find out when you can tune in for the scheduled NatHERS webinars.

A view from the outdoor courtyard towards the house with a timber deck and large sliding glass doors
Photo: Finn Howard (© Finn Howard Photography)

Energy Efficiency Conference

The NatHERS team recently presented at the 2022 National Energy Efficiency Conference in Melbourne 25-26th May. This year’s theme was energy efficiency as the first fuel for net zero. NatHERS presenters discussed updating building tools for net zero, retrofitting the 8 million poor performing existing homes across Australia, and translating net zero aspirations into action.  

NatHERS was also part of the conference exhibition. Staff talked to lots of delegates interested to learn more about the NCC 2022 changes and implications for minimum standards for existing buildings. The Your Home team was also present with the 6th edition of Your Home available for purchase.   

Conference highlights can be viewed on the Energy Efficiency Council website.

Photo of the Your Home and NatHERS booth at the Energy Efficiency Conference
Photo: Melissa Hobbs (supplied by Energy Efficiency Council)

GreenSmart Awards and Symposium

The Housing Industry Association (HIA) Australian GreenSmart Awards recognise those who build or design environmentally-friendly homes and provide solutions to make homes more efficient. 

Winners of the 2022 HIA GreenSmart Awards will be announced on Thursday 15 September in Canberra. The GreenSmart Symposium will also take place on 15 September, facilitating a high-level discussion around sustainability, regulation, solutions to waste and innovation. 

Reach out to HIA for more information.