NatHERS Whole of Home rating for new-home certificates
Whole of Home is the 0 to 100+ score on a new-home certificate. It looks at fixed energy systems such as heating, cooling, hot water and solar alongside the thermal Star Rating. If the home is already built, you need the separate Home Energy Rating service.
Official guidance reviewed 1 September 2026Whole of Home requirements depend on the National Construction Code pathway adopted for the project location. Confirm the current requirements with the relevant approval authority.
Desktop assessment across AustraliaWhole of Home modelling uses the project's coordinated plans, specifications and fixed-system selections, so the desktop assessment can be delivered for projects across Australia. Jurisdictional approval requirements still apply.
What the score means
The home design and its fixed energy systems
New-home energy systems
Model major fixed energy use
Whole of Home modelling brings major fixed appliances and on-site energy systems into the new-home assessment alongside the building's thermal performance.
Modelled design inputs
The result depends on the fixed systems and energy features recorded for the proposed design. It is not a guarantee of a future household's energy use or bill.
Inputs commonly considered
Heating and cooling systems
Hot water and fixed appliances
On-site solar generation
Battery storage where relevant
Rating scale
A Whole of Home rating from 0 to 100+ on the applicable new-home certificate, with higher results representing stronger modelled whole-home performance.
The thermal Star Rating describes the modelled heating and cooling demand of the building shell. Whole of Home adds the effect of major fixed systems and on-site energy.
One does not replace the other
A strong result on one scale does not remove the need to understand the other. The design, systems and approval evidence need to remain coordinated.
Read together
Thermal Star Rating from 0 to 10
Whole of Home rating from 0 to 100+
Modelled systems and assumptions
Certificate status and design revision
Design use
A clearer view of how the proposed building fabric and specified energy systems work together under the standardised model.
A completed home can receive a Home Energy Rating from 0 to 100+ and a Star Rating from 0 to 10 after an on-site assessment, but that service is not called Whole of Home.
Whole of Home means new home
Use Whole of Home for the new-home certificate pathway. Use Home Energy Rating for the current assessment of an existing home.
Choose by building stage
Proposed design uses new-home assessment
Completed home uses on-site assessment
NCC evidence uses the new-home pathway
Existing-home results support upgrade decisions
Clear communication
Correct naming helps households, designers, assessors and approval authorities understand which evidence is being discussed.
Identify the project, jurisdiction, approval route and whether the applicable new-home certificate must include Whole of Home modelling.
02
Coordinate building and systems
Provide the same design revision used for thermal modelling, together with the proposed major fixed appliances, solar and battery details.
03
Model both rating components
Assess the thermal performance and the fixed whole-home energy systems under the current NatHERS method and software.
04
Resolve design gaps
Review practical changes to the shell or fixed systems while choices can still be coordinated across the project.
05
Maintain certificate alignment
Keep the certificate, approved plans, schedules and installed design aligned when products or project details change.
Official source
Official explanation of the Whole of Home rating
The Home Energy Rating new-home certificate guide explains the Whole of Home scale, the thermal Star Rating and the information recorded on the certificate.
Yes. Whole of Home is the 0 to 100+ rating used in the new-home certificate pathway. The current service for a completed home is called Home Energy Rating, even though its overall scale also runs from 0 to 100+.
Does Whole of Home replace the NatHERS Star Rating?
No. The thermal Star Rating from 0 to 10 and Whole of Home rating from 0 to 100+ describe different parts of the proposed design and can both appear on the new-home certificate.
Is a 100 rating an energy-bill guarantee?
No. The Whole of Home score is a standardised model using the design and system assumptions recorded for the assessment. Actual bills depend on occupancy, behaviour, weather, tariffs, construction and equipment operation.
Can Whole of Home support NCC evidence?
It can form part of the relevant new-home certificate evidence for National Construction Code energy performance. The jurisdiction and approval authority determine the exact pathway and evidence that must be accepted.
Need a Whole of Home rating?
Tell us about the project and current plans
Start with the location, design stage, approval contact and the fixed systems already selected. We will explain what evidence is still needed.
