Frequently Asked Questions (FAQ)

Daniela Russo

Updated July 15, 2025 00:39

Below are some frequently asked questions that may assist you in using Hero energy-rating software:

If you do not find what you are seeking below then, please contact your AAO, or visit their help sections such as Design Matters TPA FAQ , HERA Knowledge Hub , ASBA/BDAA Notes

---

Chenath Maximum Object Limits:

Chenath has several limits on the maximum number of objects it can successfully model, including Zones, Windows, Skylights and other assembly limits.

If your project is not simulating due to these Chenath limits, you can attempt the below solutions.

If you need to diverge from NatHERS Technical Guidance to successfully run your dwelling, then any amendments should be noted in the NatHERS Certificate Notes section.

Zones

Chenath has a maximum number of Zones of 150 per dwelling, which includes normal zones as well as 'special' zones such as roofspace, subfloor and reflective air-space zones.

Chenath models ceilings and floors with reflective air-spaces as several separate zones (to model surface temperatures) which can quickly mean the 150 max zone limit is exceeded when using reflective ceiling/roof insulation.

Likewise if your ceiling has uninsulated and insulated sections (e.g. due to penetrations like downlights or penetrations) it will create a second ceiling in each zone where this occurs (which can also then increase the number of reflective air-space zones too).

If you are encountering maximum zone number limits, you can try to reduce the number of zones by insulating all penetrations in the zone; or combining small zones into single zones; or modelling non-reflective ceiling insulation until you are able to successfully get the simulation to run.

Windows & Skylights

Chenath also has a maximum number of windows of 30 per zone, and maximum number of skylights of 10 per zone. If you encounter these limits then windows and skylights should be combined into similar single windows and skylights until your simulation can successfully run.

Walls & Roofs

Chenath has a maximum number of walls and roofs of 200 per dwelling. If you encounter these limits then walls or roofs should be combined into similar single roofs or walls until your simulation can successfully run.

---

Training:

Q: I completed the training course some time ago and now I have uploaded a project and Hero is telling me I am unaccredited, what is going on?

A: Hero's training course is dynamic and requires NatHERS Accredited Assessors to continue to remain "up to date" with their training to produce new certificates.

If you have completed the course previously and the untrained or unaccredited alert message is now being shown at certification, then go to the Training Portal and go into the Hero-101 course and look through the training modules and make sure you haven't missed one. New updates are always easy to complete but are to ensure that assessors know new functionality and continue to use the tool correctly and efficiently.

Note that the training portal considers you to have "completed" the Hero-101 training course even if there are still modules left to do, so you must click into the Hero-101 course to see any incomplete modules (so that your AAOs know you have completed it once which is all they care about).

---

Accreditation:

Q: Is Hero accredited for use by NatHERS?

A: Yes, Hero has been approved for use within the NatHERS Scheme for Class 1a, 2 & 4 Building classifications for new & existing buildings. Please see the list of accredited software tools at the NatHERS government web-site

Q: What calculation engine does Hero use?

A: Hero uses CSIRO’s Chenath engine, has a license from CSIRO to use this within our platform, and pays royalties to CSIRO for the purchase of NatHERS certificates on our platform. You can find more details about on our Resources page

Q: Is Hero accredited for use with BASIX in NSW?

A: Yes, Hero has been approved by the BASIX administration for use in NSW. For further details see:

We also have integrated the BASIX heating & cooling load limits so you can easily see current project compliance within Hero.

Q: Is Hero accredited for use in ACT?

A: Yes, Hero has been approved in the latest update of the ACT building regulations where the previous dedicated prescribed software versions have been replaced by the use of any NatHERS Accredited Software package. For more information see: https://www.legislation.act.gov.au/ni/2023-843/

---

Modelling & Assessments:

Q: Can Hero model Internal Surface Solar Absorptance / Colours?

A: Yes these can be changed for floors, walls in the Data-Grid and Summary-View, however they are hidden by default so must be turned by clicking the overflow buttons in the far-right header of the tables to turn on.

Q: Can Hero model Green Roofs?

A: Yes, the Hero ceiling assembly list includes some Green Roof options however these are based on the use of the standard Soil material from the Chenath Materials library which has a relatively high thermal conductivity. Upcoming changes to the NatHERS materials database will include some green roof soil materials that we will integrate into our green roof assemblies.

Q: What material should I use to model Hempcrete?

A: Hempcrete is not a material available in the NatHERS Material Library and therefore can only be modelled by proxying it with a similar material type. This will depend on the specific Hempcrete R-value, thickness, density and specific-heat (thermal mass) which can vary per product (density and specific-heat can be optionally added to the Wall Assembly Table columns). Several materials that are similar are "Carpet with Rubber Underlay" that matches Hempcrete well in terms of insulation density and thermal-mass, though softboard, strawbale, and AAC are somewhat close.