7-Star Energy Certificates vs 6-Star: What’s the Difference, Why It Matters, and Where It Applies in Australia

If you’re planning a new home or major renovation, you’ve probably heard a lot about “7-star energy certificates.” In short: Australia has lifted the minimum thermal performance for new homes from 6 stars to 7 stars under the National Construction Code (NCC 2022), and most states and territories have now implemented those requirements (with a few exceptions and transitional arrangements). This article breaks it all down in plain English so you can make confident decisions—and avoid costly redesigns—before you lodge your plans.

First, what is a 7-star rating and an energy report?

Australia uses the Nationwide House Energy Rating Scheme (NatHERS) to model how much energy your home will need for heating and cooling each year, based on your plans and specification (orientation, glazing, insulation, shading, materials, etc.). The result is a thermal star rating from 0 to 10: the higher the stars, the less energy required to stay comfortable. Since NCC 2022, NatHERS certificates can also include a Whole-of-Home score that estimates total annual energy use from fixed appliances (heating/cooling, hot water, lighting, pool/spa), and credits on-site solar/batteries. (NatHERS)

An energy report (often called a “NatHERS report” or “star rating report”) documents those results and the specification needed to achieve them. Your building surveyor/certifier uses it to check compliance with the NCC or, in NSW, BASIX. (NatHERS)

7-Star vs 6-Star: what actually changes?

1) Thermal performance target

2) The specification to get there

To move from 6 to 7 stars, plans commonly require smarter passive design and, in many cases, upgrades such as:

These are part of the “first principles” the NCC and NatHERS guidance emphasise for cost-effective 7-star outcomes. (National Construction Code, yourhome.gov.au)

3) Whole-of-Home energy budgeting (NCC 2022)

Under NCC 2022, new houses and apartments also need to meet a Whole-of-Home energy budget, assessed in NatHERS software. It sums the expected annual energy use of fixed systems (heating/cooling, hot water, lighting, pool/spa) and then subtracts on-site generation/storage (solar PV + batteries). Think of it as a second test alongside the star rating: the building fabric must be efficient and the major services must be sensibly specified. (NatHERS, National Construction Code)

What are the advantages of a 7-star energy report for consumers?

Lower bills, year after year

Because a 7-star shell needs less heating and cooling energy, you spend less to stay comfortable—an advantage that compounds over the life of the home (and only grows as energy prices rise). Government and industry sources consistently peg the heating/cooling savings around 20–25% compared with 6 stars, depending on climate and design. (Sustainability Victoria)

Greater comfort and resilience

7-star homes hold temperature far better during heatwaves and cold spells, meaning fewer hot/cold rooms, smaller temperature swings, and quieter HVAC because systems can be downsized and run less often. This makes daily life more comfortable and reduces peak-demand stress on the grid. (National Construction Code)

Better design discipline (and better resale)

Reaching 7 stars drives good design decisions early—orientation, glazing percentages, shading—that improve liveability and natural light. Buyers increasingly understand (and demand) energy-efficient homes; a compliant 7-star design with a strong Whole-of-Home score is a marketable feature.

Future-proofing against code changes

The NCC is on a trajectory toward even higher performance over time. Designing for 7 stars now (and considering an all-electric, solar-ready approach) helps future-proof your investment and avoid retrofits later. (NatHERS)

Health and well-being

Efficient envelopes reduce drafts, condensation risk, and temperature extremes—factors linked to fewer respiratory issues and mould problems. That translates to healthier indoor environments for families. (National Construction Code)

Where (and when) is the 7-star minimum required?

NCC 2022 took legal effect on 1 May 2023, with each state/territory setting its own adoption and transition timetable. Here’s the snapshot (residential energy efficiency only), current at the time of writing:

Tip: If you’re designing now, plan for 7 stars and Whole-of-Home regardless of location. Even where transitional arrangements still exist, most lenders, buyers and certifiers are expecting the uplift.

What does a 7-star energy report include?

A typical report (based on your plans, sections and specification) will include:

  1. Thermal star rating (0–10) and zone-by-zone modelling assumptions
  2. Fabric specification needed to achieve the rating (insulation R-values, glazing U-values/SHGC, frame types, thermal breaks, roof colour, slab/floor construction, etc.)
  3. Thermal load breakdown (heating vs cooling) and climate file used
  4. Whole-of-Home outcome (where required), including appliance schedules and any on-site PV/battery contribution
  5. Compliance statement: confirmation that the design meets the NCC 2022 energy efficiency performance provisions (or BASIX for NSW), subject to construction matching the report.

How to reach 7 stars cost-effectively

From thousands of projects, the winning formula is design-first, specification-second:

  1. Orientation & layout
  2. Prioritise north-facing living areas where possible; limit west-facing glazing; stack windows to capture breezes. These moves are “free” on paper and save costly upgrades later. (National Construction Code)
  3. Right-sized, better-placed windows
  4. Improve daylighting while managing solar gains. Use higher-performance glazing strategically rather than upgrading everything. (yourhome.gov.au)
  5. Insulation & thermal breaks
  6. Lift roof/ceiling R-values; insulate slabs/edges where climate-appropriate; include thermal breaks in metal framing or window systems to cut heat flow. (yourhome.gov.au)
  7. Shading & roof colour
  8. Fixed eaves, adjustable external shading, light-coloured roofing in hot climates—all deliver outsized gains at low cost. (yourhome.gov.au)
  9. Airtightness & detailing
  10. Seal penetrations, fit quality door seals, and pay attention to construction joints. Better airtightness improves comfort and can allow smaller HVAC. (National Construction Code)
  11. Whole-of-Home choices
  12. Prefer high-efficiency, all-electric systems (heat-pump hot water; high-efficiency reverse-cycle for heating/cooling; LED lighting).
  13. If roof space allows, solar PV meaningfully improves Whole-of-Home outcomes and reduces bills. (NatHERS)
  14. Engage your assessor early
  15. Small plan tweaks (window size/placement, eave depth) can be the difference between 6.7 and 7.1 stars. Early modelling avoids late surprises.

7 stars and NSW: how BASIX fits in

NSW runs its own compliance pathway—BASIX—rather than adopting the NCC residential energy provisions directly. As of 1 October 2023, Enhanced BASIX lifted thermal performance and energy targets to broadly align with the national 7-star uplift and Whole-of-Home intent, but compliance is demonstrated through BASIX certificates, not a straight NCC check. Your assessor will model your design using the BASIX engines and generate the certificate for your DA/CC. (National Construction Code)

What about renovations, extensions and multi-unit projects?

FAQs

Is a 7-star home always more expensive to build?
Not necessarily. Many projects reach 7 stars through design optimisation rather than costly materials. Where upgrades are needed (some glazing, extra insulation), the running-cost savings and comfort gains generally pay back over time—and help resale. (National Construction Code)

What’s the Whole-of-Home score “out of 100”?
It’s a separate rating indicating how your fixed appliances and any solar/battery perform together on an annual energy budget; 100 represents net-zero operational energy use over a year (scores above 100 are possible if you generate more than you use). (NatHERS)

Do I still need a report in NSW?
Yes—just via BASIX rather than a standard NCC residential energy check. We’ll advise on the most efficient BASIX pathway for your design. (National Construction Code)

What if my project spans a transition date?
Transition rules vary. To avoid risk, design for 7 stars now and keep your documentation aligned with the current state-based requirements. (National Construction Code)

How Floyd Energy can help

Whether you’re at concept stage or ready to lodge, our assessors specialise in practical, buildable 7-star solutions that protect your budget and program:

Bottom line

Moving from 6 to 7 stars is more than a number change. It’s a step-change in comfort, resilience and running cost—and in most of Australia, it’s now the minimum for new homes. With early advice and smart design, achieving 7 stars is straightforward and affordable—and the benefits last for decades.

If you’d like us to review your plans and show you the quickest path to a compliant, comfortable 7-star home, get in touch with Floyd Energy and we’ll start with a no-nonsense upfront assessment.

References & useful links

Note: Codes and adoption dates are accurate at the time of publication, but jurisdictions can update their timelines and guidance. We’ll confirm the latest position for your specific project when we prepare your report.

What does an accurate Energy Rating Report look like?

One of the biggest issues we find in the home and commercial building energy rating industry is the huge discrepancy in pricing and turn-around times for a report. Energy rating businesses can take advantage of a lack of industry regulation and marketplace understanding around what a good energy rating should deliver.

This bears the question: What should an accurate and helpful Energy Rating Report look like and detail?

Unfortunately, not all energy rating reports are created equal. We are often contacted to review reports after designers and builders discover issues that result from recommendations not being viable. This may mean extra costs because of un-buildable specifications.

Below we detail what you should expect from a good energy rating report that has helpful and buildable specifications that will deliver long-term energy savings and occupier comfort.

This should also, hopefully, provide clarity as to what’s a reasonable price and timeframe to undertake the work.

What our Energy Rating Report details

Our Premium Energy Rating Report includes all the above but with an extra page of further detail and analysis of the thermal elements pertaining to your project, such as glazing, insulation, shading, ventilation, thermal mass. This provides you with a greater understanding of how and why we’ve achieved the energy rating and the recommendations to deliver greater energy efficiency.

We’ve detailed a good report, we need to also discuss an unhelpful one.

We’ve seen them time and again; a simplistic one-page report that only details the requirements for a home or commercial building to reach the minimum star rating. That’s it.

Usually there is only one recommendation for each energy rating criteria (e.g. windows, ceilings, walls, slabs) irrespective of whether the material specifications can be sourced or built with your specific design and/or plan.

The biggest issue, usually, is the lack of material options for different locations of the home/building. For example, one window recommendation regardless of the building positioning.

There’s no clarity what method is used to calculate the rating or why. There’s no clarification of the starting (submitted) design/plan and what rating this would achieve. There’s no clear recommendations of how to increase the rating to achieve the minimum rating requirement.

We must clarify that this type of report will meet a building permit application requirement, but is unlikely to be helpful in delivering a house or building that is actually energy efficient. 

What's the value in an accurate energy rating report?

If your quote is offering a report at a very low cost and delivery time within 24 hours, consider what you’ll receive - what can possibly be assessed accurately within that time period? Then consider the extra spend on an accurate rating report and how that will save you in the long run and ultimately increase the value of the property itself.

If you're interested in the latter, we'd love to hear from you!

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