Heating & cooling
Installed system types, efficiencies and the energy needed to condition the home.
NATHERS WHOLE OF HOME
Beyond the star rating.
See the complete picture.
Whole of Home brings the building fabric, fixed appliances and on-site energy together—so the project’s overall energy performance can be understood and improved.
ERA SERVICE AREA ACT · VIC · QLD
PERFORMANCE RATING0—100WHOLE HOME ENERGY USE
ACTWHOLE OF HOME
VICWHOLE OF HOME
QLDWHOLE OF HOME
WHAT IS WHOLE OF HOME?
The energy story does not end at the building envelope.
NatHERS provides two connected results: a thermal star rating out of 10 and a Whole of Home performance rating out of 100.
The thermal rating measures the performance of the floors, walls, ceilings, roof, windows and doors. Whole of Home expands the assessment to consider the energy used by fixed systems and appliances, together with solar generation and batteries where included.
This gives builders and design teams a clearer view of how the home is expected to perform as one complete system.
WHAT IS ASSESSED?
Every major energy input,
working together.
Whole of Home looks at more than the efficiency of an individual product. The combination of systems, fuels, thermal performance and on-site generation determines the final result.
Hot water
System type, fuel source, efficiency and any connection to on-site solar.
Lighting
Fixed lighting power across the home, recorded as watts per square metre.
Cooking
The energy source and technology nominated for the cooktop and oven.
Solar & batteries
On-site solar PV generation and battery storage where they form part of the design.
Pools & spas
Fixed pumps and associated equipment where a pool or spa is included.
WHERE IT APPLIES
One national framework.
Three jurisdictional pathways.
ERA provides Whole of Home assessment support across the ACT, Victoria and Queensland. The required target and compliance pathway can vary by location and project type, so we confirm the applicable requirements before assessment.
Whole of Home applies
The ACT has its own energy-use settings within the NCC pathway. ERA confirms the applicable target for the project.
Whole of Home applies
Whole of Home forms part of Victoria’s residential energy-efficiency requirements for applicable new homes.
State variations apply
Queensland uses Whole of Home energy provisions with state-specific options and variations.
THE ERA APPROACH
Coordinate early.
Avoid late surprises.
Start with the thermal model
We use the actual thermal performance of the home as the foundation for the Whole of Home assessment.
Model the intended specification
We record the fixed systems, fuels and on-site energy measures that are intended to be documented and built.
Test practical combinations
Where the target is under pressure, we review the available levers and explain the impact of different options.
Keep the documents aligned
We help ensure the assessment, plans and specifications tell the same story before certification.
WHAT WE NEED
A clear appliance and energy specification.
Accurate selections produce a more representative result. Where information is not supplied, prescribed defaults may need to be used.
NatHERS assessment details
The completed thermal model and project information that form the basis of the rating.
Heating, cooling & hot water
System types, fuel sources, capacities and available efficiency information.
Lighting & cooking
Lighting power density plus the nominated cooktop and oven energy sources.
On-site energy & other systems
Solar PV and battery details, together with pool or spa equipment where applicable.
COMMON QUESTIONS
Whole of Home, explained simply.
Is Whole of Home the same as the NatHERS star rating?+
No. The star rating measures the thermal performance of the building shell. Whole of Home adds the fixed appliances, services and on-site energy systems to produce a separate rating out of 100.
Does every home need solar panels to pass?+
Not necessarily. The result depends on the complete combination of thermal performance, systems, appliances and any on-site generation. ERA can test the appropriate options for the project.
Why do appliance selections need to be confirmed?+
The assessment should reflect the documented design. If required information is not available, default values may be used and these can affect the result.
Can a higher thermal star rating improve Whole of Home?+
Yes. Better thermal performance generally reduces predicted heating and cooling energy, which can improve the Whole of Home result.
What if the design changes after assessment?+
Changes to the thermal model, fixed systems, fuels, solar or battery specification may change the rating. Relevant revisions should be reviewed before the final documents are issued.
START WITH ERA
Need the whole project coordinated?
Send us the plans and intended specification. We’ll confirm the assessment pathway and information required.