It’s easy to feel confident when purchasing a newly constructed home. With a relatively recent build, buyers often assume it complies with current building standards and will be more comfortable than an older property.
While this is true most of the time, there is no guarantee that this alone will be enough.
Victoria adopted the 2022 energy efficiency provisions under the NCC. While one of the most significant changes was the shift from a 6-star to a 7-star NatHERS rating, there were also broader changes relating to energy performance, including fixed appliances and hot water systems.
For buyers, the challenge is understanding what this standard actually means once the house has been completed. A sales brochure may mention a 7-star rating, but that does not necessarily mean the insulation has been installed correctly or that the glazing matches the required specifications.
A pre-purchase building inspection does not re-rate a home’s energy performance, but it can identify visible issues that deserve further investigation.
From 6-Star to 7-Star: What Changed and When
For many years, new homes in Australia were generally required to achieve a minimum 6-star NatHERS rating. NatHERS stands for the Nationwide House Energy Rating Scheme and measures how efficiently a home’s design maintains comfortable indoor temperatures throughout the year.
The NCC 2022 introduced a higher minimum requirement of a 7-star NatHERS rating for most new homes. Victoria adopted these provisions for new building approvals, although some projects approved before the transition continued under the previous requirements.
This change forms part of a broader effort to improve the energy efficiency of Australian homes beyond heating and cooling performance. In addition to the building’s thermal efficiency, the updated provisions also consider how much energy the home is expected to consume through its fixed services.
This is where many buyers become confused.
The NatHERS rating and the whole-of-home energy requirement are related, but they measure different aspects of a home’s performance.
A NatHERS rating focuses on the home’s thermal envelope. It measures how effectively the building prevents heat entering during summer while retaining warmth throughout winter.
The whole-of-home energy requirement looks beyond the building envelope. It considers the efficiency of fixed systems such as hot water, heating and cooling, lighting and, in some cases, the home’s readiness for renewable energy technologies.
Together, these requirements are intended to create homes that are both comfortable to live in and more affordable to operate over the long term.
It’s also important to understand which homes are required to meet these standards.
The 7-star requirements generally apply to new homes, as well as major renovations and additions that require approval under the current NCC provisions. Existing homes do not automatically need to be upgraded to a 7-star rating simply because they are being sold. A house built 20 years ago can still be sold without meeting the newer standard.
This distinction is important for buyers comparing older homes with recently completed builds. A home built under the current requirements should, in theory, provide better thermal performance than one constructed under earlier versions of the code.
What a 7-Star Rating Actually Requires on Site
Achieving a higher energy rating does not rely on one particular building element. Instead, it is the result of several components working together.
Some improvements are visible during construction. Others become hidden once plasterboard and finishes have been installed.
Understanding the main components helps buyers know what can be discussed during a building inspection.
Building envelope requirements
The building envelope creates the barrier between the inside of the home and the outside environment. Its quality has a significant influence on indoor comfort and heating and cooling costs throughout the year.
Increased insulation levels
One of the most noticeable improvements in modern homes is the higher level of insulation now expected.
Ceiling insulation generally has a higher thermal rating than products used under previous building standards. External walls are also expected to provide better insulation performance, while suspended timber floors or other subfloor areas may require insulation depending on the home’s design.
Most of this work is hidden once construction has been completed, but roof spaces can provide useful clues. During an inspection, it may be possible to see whether insulation appears continuous, whether batts have shifted out of place, or whether gaps exist around service penetrations or access hatches.
Even high-quality insulation performs poorly if it has been compressed, folded or installed with gaps.
Improvements in windows and doors
Windows have traditionally been one of the main areas where heat is lost from a home.
The updated energy provisions place greater emphasis on glazing performance. Depending on the home’s design, this may involve double glazing, improved window frames or glazing products with lower U-values.
Door systems may also contribute through improved sealing and better thermal performance.
Although inspectors can usually identify whether glazing is single or double glazed, confirming the exact specifications generally requires documentation provided by the builder or manufacturer.
Improved air leakage control
Small air leaks may seem insignificant on their own, but together they can reduce the energy performance of an otherwise well-built home.
Modern building practices place greater emphasis on sealing around windows, doors, exhaust vents and other openings where uncontrolled air movement commonly occurs.
During an inspection, visible gaps, worn seals or unfinished areas around external openings may be identified where access allows. These observations can highlight potential issues, although they do not measure airtightness itself.
Whole-of-home energy requirements
The second part of the updated standards focuses on the efficiency of the home’s fixed services rather than the building structure alone.
Efficient hot water systems
A significant portion of household energy use comes from heating water.
Depending on the home’s design and compliance pathway, the builder may install an efficient heat pump hot water system, a high-efficiency gas system where permitted, or another approved solution to help meet the whole-of-home energy target.
Buyers should understand the type of hot water system installed, its age and whether supporting documentation is available.
Solar readiness and renewable energy considerations
Not every property is required to include rooftop solar panels. However, many modern homes are designed with future energy efficiency in mind.
Depending on the design, electrical infrastructure may make future installation of solar panels or battery systems easier than it would be in older homes.
Understanding whether these provisions were included can be useful for buyers considering future upgrades.
Efficiency of fixed lighting and appliances
The whole-of-home assessment also considers the efficiency of fixed lighting and certain permanently installed appliances.
Builders commonly install LED lighting as part of the compliance pathway, while heating and cooling systems also contribute to the home’s overall energy performance.
Although these improvements may seem relatively minor on their own, together with better insulation and glazing they can make a meaningful difference to overall energy efficiency.
What an Inspector Can (and Cannot) Check Once Construction Has Completed
One of the most common misconceptions among buyers is that a building inspection confirms a home’s advertised energy rating.
This is not the case.
A building inspector assesses the condition of the property and reports on visible defects and accessible building elements. While some aspects of the home’s energy performance can be assessed visually, others cannot be verified once construction has been completed.
Where roof spaces are safely accessible, a building inspector may be able to confirm the apparent presence of insulation, whether it appears evenly installed and whether there are obvious exposed sections.
Window glazing can often be identified as either single or double glazed, while the condition of window and door seals may also be noted.
These observations provide useful information, but they do have limitations.
Wall insulation sits behind plasterboard. Floor insulation may be hidden beneath finished flooring. The actual thermal performance of windows cannot usually be confirmed through visual inspection alone. The same applies to determining whether the completed building fully matches the original energy assessment.
This is why a post-construction inspection cannot recreate or recalculate the original NatHERS rating.
The original assessment is prepared through an accredited process that considers building plans, specifications, orientation, glazing schedules and other technical information that is not available during a standard inspection.
When purchasing a newly built home, buyers should request the original NatHERS certificate together with the whole-of-home energy assessment.
These documents show what the home was approved to achieve. A building inspection then provides an opportunity to compare the visible construction with the approved documentation and identify any obvious inconsistencies.
Red Flags for Purchasers of Newly Built or Recently Renovated Houses
A house that has been recently constructed or refurbished might look impressive on the surface, but appearances do not always tell the full story. Construction issues are not limited to structural defects. In some cases, energy efficiency measures may also fall short of what was originally approved.
Not all issues can be identified without specialised testing or supporting documentation, but there are several warning signs buyers should look out for during a pre-purchase inspection.
Partial or Improperly Installed Roof Insulation
Roof spaces are among the few areas where insulation may still be visible after construction has been completed.
An inspector might notice insulation batts that have shifted out of place, insulation that has been compressed and therefore performs less effectively, or sections where insulation is missing around roof penetrations, access hatches or service installations. Sometimes, tradespeople working in the roof space after construction accidentally disturb the insulation and fail to reposition it correctly.
These issues do not automatically mean a home fails to meet the required energy rating, but they can affect comfort and increase heating and cooling costs over time.
Single Glazing in a Recently Constructed Property
If a property is advertised as being built to current building standards, it is worth taking a closer look at the windows.
Many homes designed to achieve a 7-star NatHERS rating include higher-performing glazing, although the exact specification depends on the home’s design and compliance pathway. Finding standard single glazing in a recently completed property may raise questions about the documentation supporting its energy compliance.
It is also worth remembering that glazing performance is not determined solely by the number of panes. The frame material and other technical specifications also contribute to its overall performance.
Lack of Compliance Documentation
Sometimes the first warning sign is simply the absence of documentation that the seller cannot provide.
For newer homes, documentation relating to energy compliance should generally be available. This may include the NatHERS certificate, the whole-of-home energy report and product information covering major energy-related components such as glazing or insulation where applicable.
While missing documents do not automatically indicate a problem, they do make it harder for buyers to verify whether the home was built in accordance with the approved specifications.
Renovations Inconsistent With the Age of the House
Major renovations can make a property look more modern, but cosmetic improvements do not always reflect upgrades behind the walls.
Fresh paint, new flooring and a modern kitchen can easily draw attention away from older windows, limited insulation or building elements that were never upgraded. If substantial renovation work has been completed, it is worth asking whether the project required a building permit and whether current energy efficiency requirements formed part of the approved works.
What It Means for You Beyond Comfort: The Cost Implications
Energy efficiency is often discussed in terms of sustainability, but the practical benefits extend well beyond environmental considerations.
An energy-efficient home generally requires less energy to maintain a comfortable indoor temperature. In Melbourne, where winters are cold enough to require months of heating and summer heatwaves can place heavy demands on cooling systems, this difference can become noticeable in household energy bills.
Good insulation slows the movement of heat through the building. High-performing windows reduce heat entering the home during summer while limiting heat loss throughout winter. Effective sealing also helps prevent conditioned air from escaping through gaps around windows, doors and other openings.
None of these features eliminates energy costs altogether, but together they can reduce the amount of heating and cooling needed to keep the home comfortable.
Comfort itself is another factor that buyers sometimes underestimate.
A home that maintains more stable indoor temperatures generally feels more comfortable throughout the day. Rooms are less likely to become excessively hot in the afternoon or noticeably colder overnight. Good sealing also reduces draughts around windows and external doors, helping maintain a consistent indoor temperature without relying as heavily on heating or cooling systems.
These qualities have become increasingly important as more buyers consider long-term running costs alongside the purchase price.
Energy-efficient homes may also attract stronger buyer interest when they return to the market, as energy performance is becoming another factor purchasers consider when comparing similar properties.
If settlement has not yet taken place, arranging a pre-settlement inspection provides an opportunity to identify visible defects before ownership changes hands. While a building inspector cannot verify every aspect of the home’s energy rating, they may identify issues such as incomplete roof insulation, damaged glazing, missing weather seals or workmanship defects that are often easier to address before the builder’s obligations come to an end.
Resolving these issues before settlement is usually much easier than arranging rectification work after moving in.
Buying With Confidence Means Looking Beyond the Brochure
The move to a minimum 7-star energy rating is an important step towards improving the energy performance of new homes across Victoria. For buyers, however, the rating itself is only part of the picture.
A home’s energy performance depends not only on its original design but also on how accurately that design has been delivered during construction.
A thorough pre-purchase or pre-handover building inspection helps determine whether the visible construction reflects the quality expected from a modern home. When combined with the original NatHERS certificate and supporting compliance documentation, it gives buyers a clearer understanding of what they are purchasing and helps reduce the risk of unexpected issues after settlement.
Frequently Asked Questions
Are all new dwellings in Victoria supposed to have a 7-star energy rating?
Almost all new homes and many major renovations covered under the NCC 2022 provisions in Victoria are required to achieve a minimum 7-star NatHERS rating, together with the separate whole-of-home energy requirement. Some projects approved before the transition period may still have been assessed under the earlier provisions.
Is it possible for a building inspector to verify the NatHERS star rating of the house?
No. A building inspector can assess visible features that contribute to a home’s energy performance, such as insulation, glazing and weather sealing, but they cannot recalculate or certify the home’s NatHERS rating.
Must an existing older house satisfy the new 7-star regulations?
No. Existing homes do not need to be upgraded simply because they are being sold. The newer energy efficiency requirements generally apply when a new home is built or when major renovations or additions require approval under the current building provisions.
What should I ask for when buying a newly built Melbourne home?
Ask for the NatHERS certificate, the whole-of-home energy assessment and any available documentation covering insulation, glazing and other relevant energy efficiency specifications. Reviewing these documents alongside a professional building inspection provides a much clearer picture of whether the completed home reflects its approved design.
