A Home Energy Rating and residential Deemed-to-Satisfy compliance can both become relevant when an existing Australian home is being reviewed, renovated or upgraded.
They do not, however, answer the same question. A Home Energy Rating assesses how an established dwelling performs as it currently exists. DTS compliance demonstrates that proposed building work follows applicable National Construction Code provisions.
Understanding that distinction helps homeowners, renovators and project teams request the correct assessment and avoid treating one document as a substitute for the other.
A Home Energy Rating explains the performance of the existing dwelling. DTS compliance addresses the proposed building solution.
In Brief
A Home Energy Rating assesses an existing dwelling and helps describe its thermal performance, whole-of-home energy use, installed systems and current performance characteristics.
DTS, or Deemed-to-Satisfy, is an NCC compliance pathway. It is used where proposed building work follows provisions or recognised assessment methods that are deemed to satisfy the relevant Performance Requirements.
A Home Energy Rating certificate for an existing dwelling cannot be used as evidence that proposed building work complies with the NCC.
DTS documentation does not provide a general rating of how the retained existing home performs for comfort, energy use or upgrade potential.
A renovation may involve both pathways: one to understand the current home and another to demonstrate compliance for the proposed works.
Important terminology: A Home Energy Rating for an existing dwelling is different from a NatHERS assessment used for a new home or major renovation. NatHERS can support an NCC compliance pathway for eligible proposed residential work, while an existing-home rating assesses a dwelling that has already been constructed.
Existing Dwelling Performance
Proposed Building Work
A Home Energy Rating examines an established dwelling as it has actually been constructed and fitted out.
The assessment is not based solely on the original architectural drawings. Available plans may assist, but the rating needs to reflect the real home, including alterations, installed products and systems that may have changed since construction.
Depending on the assessment scope, relevant information may include:
The resulting certificate can include information about thermal performance, predicted household energy use, renewable energy and the home’s likely comfort without mechanical heating or cooling.
Its role is to establish a clearer performance picture of the existing property. It is not an approval document for new construction.
Explore the full existing-home framework in the Home Energy Rating Knowledge Hub.
Deemed-to-Satisfy provisions are recognised ways of satisfying relevant NCC Performance Requirements.
The project team can use an applicable DTS pathway where the proposed building solution follows the relevant provisions, assessment method and jurisdictional requirements.
For residential energy efficiency, the compliance evidence may relate to matters such as:
DTS is broader than one residential energy report. It describes a compliance approach used across the NCC.
Within residential energy compliance, an elemental DTS pathway may apply prescribed provisions directly to individual building elements. A recognised NatHERS pathway may also form part of a DTS Solution for eligible new homes or major renovations.
For the wider residential compliance framework, visit the Residential DTS Knowledge Hub.
The simplest way to distinguish the pathways is to identify the subject of the assessment.
A Home Energy Rating is concerned with the home that exists today. It asks how the dwelling performs with its current construction, windows, insulation, appliances and energy systems.
DTS compliance is concerned with a proposed building solution. It asks whether new or altered work follows the relevant prescribed provisions or recognised DTS assessment method.
This distinction remains important even when both assessments relate to the same address.
A homeowner may receive a Home Energy Rating for the existing dwelling and still need separate compliance documentation for an extension, upper-level addition, garage conversion or other approval-related work.
Yes. A renovation can involve an assessment of the existing dwelling and a separate compliance pathway for the proposed works.
Example
A homeowner is considering a rear extension and wants to improve the comfort and efficiency of the original house at the same time.
A Home Energy Rating may help establish how the existing dwelling currently performs and which retained areas may benefit from insulation, glazing, shading or systems upgrades.
The proposed extension may separately require BASIX, DTS, NatHERS or another accepted compliance pathway, depending on its location, scope and approval requirements.
The two pieces of work may inform each other, but they remain distinct.
The existing-home assessment may support better renovation decisions. The compliance assessment provides the evidence required for the proposed building work.
For more detail on the construction boundary, see Residential DTS for Alterations and Additions.
Scenario 01
The owner is not proposing approval-related building work but wants to understand comfort, efficiency and upgrade opportunities. A Home Energy Rating is the relevant starting point.
Scenario 02
The owner has drawings for an extension that requires approval. The project needs the applicable residential compliance pathway rather than an existing-home rating alone.
Scenario 03
The project includes approval-related work and broader upgrades to the retained house. A Home Energy Rating and a separate compliance assessment may both be useful.
A strong existing-home rating does not establish that an extension, alteration or conversion complies with the NCC.
Where proposed work requires approval, the applicable compliance documentation must still be prepared through the correct jurisdictional pathway.
DTS evidence confirms that the proposed solution follows the applicable prescribed provisions or recognised DTS method.
It does not provide a complete performance assessment of the retained home, a whole-of-home certificate or a structured review of broader upgrade opportunities.
Complete information is not always available at the first enquiry. The initial documents should provide enough context to identify whether the request concerns existing-home performance, proposed-work compliance or both.
Start with a Home Energy Rating when the primary question is:
Start with a compliance pathway review when the primary question is:
Frequently Asked Questions
No. A Home Energy Rating for an existing dwelling describes the home’s current energy performance. It cannot be used as evidence that proposed building work complies with the National Construction Code.
No. DTS is a National Construction Code compliance approach. It confirms that a proposed building solution follows applicable prescribed provisions or recognised DTS methods. It does not provide a general performance rating of an established dwelling.
Yes. A NatHERS assessment for an eligible new home or major renovation can form part of a recognised residential DTS compliance pathway. This is different from a Home Energy Rating prepared for an existing dwelling.
Yes. The owner may use a Home Energy Rating to understand the retained dwelling, while the proposed renovation follows a separate NCC compliance pathway for the new or altered work.
Original plans are helpful but are not always available for existing homes. Photos, property information, measurements, renovation records and details of installed systems may also support the assessment. The assessor can confirm what further information is needed.
Not as a general existing-home performance assessment. DTS documentation is prepared to demonstrate compliance for the relevant proposed building solution. It does not replace a structured assessment of the retained dwelling’s current comfort and energy use.
Not automatically. Current requirements commonly apply to new or altered work, although existing elements may need to be considered because of the jurisdiction, approval decision, project scope or selected assessment method.
Provide the property address, available existing information and any proposed renovation drawings. An initial review can then distinguish between an existing-home performance assessment and a compliance requirement for proposed building work.
Related Knowledge
Understand how existing-home assessments review current thermal performance, whole-of-home energy use and property information.
Read the foundational guide to the purpose, scope and assessment of an established Australian dwelling.
See how proposed extensions, conversions and altered work may interact with residential compliance requirements.
Residential Pathway Review
Send the available property information, photos, plans or proposed renovation documents. Certified Energy can review the request and confirm whether the next step is a Home Energy Rating, a residential compliance pathway or a combination of assessments.
Send Your Property or Project DetailsLooking specifically for an existing-home assessment? View the Home Energy Rating service.