Publications

This strategy establishes the approach to managing assessor errors, non-compliance, fraud, or other misconduct as part of NatHERS for Existing Homes. The strategy: 

• is transparent, impartial, and performed by competent people
• provides timely, credible information to inform decisions
• is adaptable to changes in the scheme; and
• complements but does not duplicate the activities of commonwealth, state or territory regulators or other compliance and enforcement agencies. 

NatHERS for Existing Homes Assurance Strategy (pdf / docx)

This Policy outlines how the Department manages the collection, storage and dissemination of NatHERS information. It is a privacy policy for the purposes of the Department’s activities as NatHERS Administrator. 

• NatHERS Information Collection, Storage and Dissemination Policy (pdf / docx)

These documents outline the method that underpins the NatHERS Whole of Home modules and rating in the benchmark tool (AccuRate Home). It includes information for calculating the energy demand of a home’s energy uses such as heating and cooling appliances, hot water systems, lighting, pool and spa equipment, plug-in and cooking appliances. It also includes information for calculating on-site solar PV generation and storage, and the Whole of Home performance rating.

Current Version

Whole of Home National Calculations Method (PDF)

Whole of Home National Calculation Method Appendices (MS Excel)

Superseded 

Whole of Home National Calculations Method  - Superseded (PDF)

Whole of Home National Calculation Method Appendices - Superseded (MS Excel)

Please contact the NatHERS Administrator via admin@nathers.gov.au if you have any questions.

This code of practice describes the key requirements which NatHERS for existing homes assessors must comply with to maintain their accreditation. It ensures that accredited assessors act with an appropriate level of care, due diligence, and professionalism.

NatHERS for Existing Homes Assessor Code of Practice (pdf / docx)

The protocol below details the requirements for third-party user interface (UI) tools using AccuRate Enterprise (AE)(existing homes) as a backend calculation engine and for accredited certificate generation.  The UI must be the only tool which assessors’ access to input and retrieve data.

Out of scope

This document does not apply to UI tools which rely on assessors accessing AE (existing homes) UI to manually complete or modify a rating file or to generate an accredited certificate from within AE (existing homes).

User Interface Protocol (docx / pdf) 

User Interface Expression of Interest

The document below details the process for applicants seeking accreditation of a user interface tool for NatHERS existing homes ratings and includes the Expression of Interest (EOI) form. Be sure to read all the information carefully and complete the EOI form in full before submitting. 

User Interface Expression of Interest Form (docx / pdf)

User Interface Terms and Conditions (docx / pdf)

The applicant must submit an expression of interest (EOI). This provides an early opportunity for the NatHERS Administrator and the applicant to clarify and identify critical barriers to accreditation.  Please note that submitting an EOI does not guarantee accreditation.

Before completing this form, the applicant should familiarise themselves with relevant documentation and resources including:

• NatHERS Existing Homes Delivery Model
• User Interface Protocol (UIP) (see above)
• NatHERS Whole of Home Calculation Method
• Existing Homes thermal standardisation and specification document
• Existing Homes Technical Note
• Existing Homes Guidance Note

Resources available on request by email to the NatHERS Administrator at uip@nathers.gov.au 

• User Interface Accreditation Notice – prototype
• Benchmark dwelling files. 

Resources available on request to the CSIRO zendesk portal

• AccuRate Enterprise and API. 

Updates to requirements processes 

• The user interface protocol and expression of interest are part of a new process being introduced by NatHERS.  As soon as updates become available, they will be posted here and updated in the relevant documents at a later date.

If you have any questions regarding the EOI process, please email uip@nathers.gov.au.

NOTE: Expressions Of Interest (EOIs) have reopened for this Technical Working Group.

The Department of Climate Change, Energy, the Environment and Water (the Department) is seeking expressions of interest to join a technical working group to inform the development of the user interface protocol for Nationwide House Energy Rating Scheme (NatHERS) tools for existing homes (www.nathers.gov.au/expansion). 

In 2019 the Australian Government invested substantial funds, with the backing of the states and territories, in the development of a ‘cloud-based’ version of AccuRate, named AccuRate Enterprise.

As part of the expansion of NatHERS to existing homes, the proposed approach is to create the opportunity for the market to develop third-party user interfaces (UI), with all calculations undertaken by AccuRate Enterprise (existing homes mode).

The user interface protocol will set out the requirements for third-party UIs to undertake home energy ratings for existing homes using AccuRate Enterprise.

This expression of interest is seeking suitably qualified and interested experts to join a technical working group that will inform the development of the user interface protocol. 

The participation in the working group does NOT disqualify applicants from future participation in pilots, trials of software or further work around the development of tools and advisory in this space. 

Please note however, the confidentiality and disclaimer section in the EOI document stating that this is a consultative activity and is not commitment to any course of action.

For details on how to submit your expression of interest refer to User Interface Protocol Technical Working Group Submission requirements.

Contact information

If you have questions, please feel free to reach out to us at admin@nathers.gov.au

This document specifies data sets, fixed inputs and validation rules for existing homes, supplements the NatHERS Software Accreditation Protocol for existing homes and sets out the thermal settings which are different to new homes. It must be read in conjunction with:

• Software standardisation document for new homes - many of the new home settings are also applied to existing homes,
• Whole of home national calculation method - covers settings for fixed appliances and energy generation and storage,
• Existing homes technical note.

Existing Homes thermal standardisation and specification (pdf)

This policy outlines how assessor performance issues are managed, including:

• how breaches of the NatHERS for Existing Homes Assessor Code of Practice will be managed, including when identified through audits
• what performance improvement actions are available and what they involve
• when suspension or cancellation of accreditation may occur and what it involves.

NatHERS for Existing Homes Assessor Performance Management Policy (pdf / docx)

The Existing Homes Technical Note outlines the requirements which must be met during a trial assessment. It clearly outlines the data required which is used to calculate the thermal performance and Whole of Home energy performance of a home.

NatHERS Existing Homes Technical Note for Trials, 27 March 2025 - Current

NatHERS Existing Homes Technical Note for Trials, 26 February 2025 - Superseded

The Existing Homes Guidance Note provides additional direction for assessors who are working onsite conducting a trial assessment. The easy reference guide helps users quickly identify the required inputs based on example images. 

NatHERS Existing Homes Guidance Note for Trials - Current

NatHERS Existing Homes Guidance Note for Trials - 26 February 2025 - Superseded