Energy equivalence building standards (star and whole of home ratings)

Since 1 May 2024, the National Construction Code 2022 (NCC) Modern Homes residential energy efficiency standards have been required in Queensland, through amendment of the Queensland Development Code 4.1 – Sustainable Buildings (QDC 4.1).

The residential energy efficiency standards apply to new houses and new units, and there two aspects required to be achieved:

7-star (out of 10) energy equivalence rating to the dwelling’s building shell
Whole of home score (out of 100) to assess the energy budget of the dwelling’s major fixtures and appliances, including any solar photovoltaic (PV) energy system.

7-star energy equivalence rating

The 7-star energy equivalence rating of new houses, townhouses and units is determined by the design of the building's shell: its roof, walls, windows and floors.

Dwellings designed to be more energy efficient are more comfortable to live in, and can provide ongoing savings to householders by minimising energy use for artificial cooling and heating. Energy equivalence is expressed on a star rating scale, with 10 stars being the highest and most energy efficient.

New houses and townhouses (class 1 buildings) must achieve a minimum 7-star energy equivalence rating. Several compliance pathways are available under QDC 4.1, including the use of optional credits of up to 1 star where the design includes a compliant outdoor living area.

New multi-unit residential buildings (class 2) must also achieve an average 7-star energy equivalence rating for all units in the building, with no individual unit to be rated less than 6-stars. This accounts for the different orientations and elevations of the individual units within the building (e.g. units with a southern orientation have less solar access).

Whole of home score

Whole of home assessments aim to lower energy costs by helping homeowners make cost-eﬀective choices about their home's major fixtures and appliances. Homeowners, designers and builders can explore the trade-oﬀs and beneﬁts of diﬀerent technologies and appliance eﬃciencies that works for them and their budget.

The Whole of home score ranges from 0 to 100 – a poor energy performing home would rate under 40, while a score of 100 is a net zero energy home. A score over 100 is possible where the home is producing more energy than it uses i.e. where it includes a large solar PV system.

A new house needs to achieve a minimum Whole of home score of 60 (out of 100) and a new unit apartment needs to achieve at least 50 (out of 100).

Energy assessments for new dwellings

An energy assessment predicts how much energy would be required to cool and heat a dwelling to maintain its comfort over a year, based on the thermal performance of its building shell (i.e. roof, walls, windows and floors).

On 1 May 2024, new residential energy efficiency standards commenced in Queensland. The new standards require an assessment of the thermal performance of the building shell and for the first time, account for the energy usage of household appliances and equipment, and energy produced by any on-site renewable energy e.g. solar photovoltaic (PV) system.

It has been more than a decade since the last change to the energy efficiency requirements for homes in the National Construction Code.

The 2 most common energy assessment methods used for residential buildings (houses and units) are:

deemed to satisfy (DTS) elemental provisions – using the more prescriptive provisions of the National Construction Code 2022 (through the Building Code of Australia—Volumes 1 and 2).
software – using one of the software tools accredited under the Nationwide House Energy Rating Scheme (BERS Pro, AccuRate , HERO and FirstRate5), a house energy assessor predicts the design's thermal performance and assesses the Whole of Home energy budget.

Regarding a building’s thermal performance, the software assessment generates a star rating between 0 to 10 stars – where a 10-star dwelling would require the least energy use for artificial cooling and heating.

In terms of household energy use, the Whole of Home rating scale ranges from 0 to 100. A score of 100 represents a net zero energy value home, while a rating over 100 is possible where the home is producing more energy than it uses.

A NatHERS Certificate confirms the star rating of the building shell and whether the home meets or beats the annual energy use budget. More information on the software assessment method is available in Building and Plumbing Newsflash 548 (PDF, 422KB).

Other energy assessment options are:

peer review by an expert (read peer review guidelines)
using a reference building by comparing to a design that is already known to comply.

Use of optional credits

In Queensland, a dwelling can use optional credits when it includes:

an outdoor living area (for houses, townhouses and units) – this option was expanded on 1 May 2024 to apply state-wide in Queensland.

The optional credits can continue to be used towards achieving compliance for the dwelling's energy rating.

The 7-star housing and multi-unit residential building requirements are regulated through the Queensland Development Code 4.1—Sustainable buildings.

Also consider...

Learn more about the Nationwide House Energy Rating Scheme (NatHERS).
Read the National Construction Code (NCC) for the construction of buildings.
Read the Housing Energy Efficiency Handbook (PDF, 8.8MB).
Read about passive design on the Australian Government's Your Home website.
Learn more about Queensland's climate zones for dwellings and buildings.

7-star energy standard for houses and townhouses

New houses and townhouses (class 1 buildings and their enclosed attached garage (class 10a)) must achieve a minimum 7-star (out of 10) energy equivalence rating. This rating is determined by the design of the building's shell: its roof, walls, windows and floors.

A house designed as 7-star (or better) is more energy efficient and comfortable to live in, and can provide ongoing savings to householders by minimising energy use for artificial cooling and heating.

How to achieve the 7–star energy rating

There are many design features that can contribute to the minimum standard for houses, including:

northern orientation of living rooms
minimising the area of east and west facing walls and windows
natural ventilation through windows and doorways
shading with wider eaves and awnings
insulation in roof space and walls
high-performance glazing
light-coloured roofs and walls
ventilating the roof space via roof and eave vents
ceiling fans in living areas and bedrooms
well-designed outdoor living areas.

The design must account for the climate of the area where the house is located. Find design tips for a specific climate zone.

Optional credits for outdoor living areas and photovoltaic systems

Optional credits for outdoor living areas can be used towards meeting the 7–star minimum standard for houses and townhouses.

For an outdoor living area, it must meet minimum design specifications:

½-star credit for a fully covered outdoor living area that is connected to an indoor living area (such as a lounge, kitchen or family room) where it has
- at least 12m² in floor area
- a minimum dimension of 2.5m in all directions
- an impervious roof with an insulation R-value of at least R-1.5
- 2 or more sides open or capable of being readily opened.
1-star credit when an outdoor living area
- meets the above requirements
- is fitted with at least 1 ceiling fan that has a speed controller and a blade rotation diameter of at least 900mm.
The floor area a fan serves must not exceed
- 15m² if it has a blade rotation diameter of less than 1200mm
- 25m² if it has a blade rotation diameter of greater than or equal to 1200mm.

The previous optional 1-star credit for inclusion of a solar photovoltaic (PV) system ceased on 30 April 2024, as this feature is now counted in the Whole of Home energy budget.

The house’s design must achieve a minimum baseline rating 6-star for the building shell when using the optional credits.

Flexible design options can be used to achieve a 7-star house. For example:

7-star building shell rating only
6½-star building shell plus a ½-star credit for the inclusion of a compliant outdoor living area
6-star building shell plus 1-star credit for the inclusion of a compliant outdoor living area with a ceiling fan(s).

Marketing houses higher than 7 stars

Optional credits are provided for regulatory purposes only to assist in complying with Queensland's 7-star standard for houses. They do not extend the Nationwide House Energy Rating Scheme (NatHERS) star range beyond 10 stars.

A house cannot be promoted as having more than 7 stars if those additional stars rely on optional credits. For example, if a house achieves a 7-star building shell rating (as per its NatHERS Certificate), the inclusion of an outdoor living area with a ceiling fan does not increase its rating to 8 stars.

The 7-star standard for houses is regulated through the Queensland Development Code 4.1 – Sustainable buildings.

Also consider...

Learn more about the Nationwide House Energy Rating Scheme (NatHERS).
Read the National Construction Code for the construction of buildings.
Read the Housing Energy Efficiency Handbook (PDF, 8.8MB).
Read about passive design on the Australian Government's Your Home website.

7-star energy standard for units

Since 1 May 2024, new multi-unit residential buildings (class 2) must meet at least a 7-star (out of 10) energy rating.

All sole-occupancy units must collectively achieve an average energy rating of at least 7 stars for the whole building, with no individual unit rated less than 6 stars. This accounts for the different orientations and elevations of the individual units within the building (e.g. units with a southern orientation have less solar access).

A 7-star (or better) unit is designed to be more energy efficient and comfortable to live in, and can provide ongoing savings to householders by minimising energy use for artificial cooling and heating.

Assessment methods

Software is the most common assessment method used to determine the energy efficiency of units. Each unit in the building must have a NatHERS Certificate. While units in an apartment building may have similar designs, they each have a different orientation and height, and will therefore have different star ratings.

For the energy efficiency of common areas and shared services, like artificial lighting and central plant facilities for air-conditioning, the National Construction Code's Volume One—Energy Efficiency (Section J) provisions apply.

How to achieve the 7-star energy rating

There are many design features that can contribute to the minimum standard for units, including:

northern orientation of living rooms (where possible)
natural ventilation through windows and doorways
shading with wider eaves and awnings
insulation in roof space and walls
high-performance glazing
light-coloured roofs and walls
ceiling fans in living areas and bedrooms
well-designed outdoor living areas.

The design must account for the climate of the area where the unit is located. Read more design tips for your climate zone.

Optional credits for outdoor living areas

Under the Queensland Development Code 4.1–Sustainable buildings (QDC 4.1), optional credits for outdoor living areas can be used towards meeting the 7-star requirement for unit buildings across Queensland when using the software assessment method. Up to a 1-star credit is provided for each unit that includes an outdoor living area, which can be used only when calculating the building's average star rating.

In recognition of Queensland's favourable lifestyle, the optional credit for outdoor living areas has been expanded to apply state-wide for apartment buildings.

For an outdoor living area with a unit, it must meet minimum design requirements:

½-star credit for a fully covered outdoor living area that is connected to an indoor living area (such as a lounge, kitchen or family room) where it has
- at least 12m² floor area
- a minimum dimension of 2.5m in all directions
- an impervious roof with an insulation R-value of at least R-1.5
- at least 1 side open or capable of being readily opened.

1-star credit when an outdoor living area
- meets the above requirements
- is fitted with at least 1 ceiling fan that has a speed controller and a blade rotation diameter of at least 900mm.
The floor area a fan serves must not exceed
- 15m² if it has a blade rotation diameter of less than 1,200mm
- 25m² if it has a blade rotation diameter of greater than or equal to 1,200mm.

In addition, where an air conditioner services the room directly adjacent to the outdoor living area it must be able to be automatically shut down when an external door that provides access to the outdoor living area is open for more than 1 minute.

Marketing star rating and optional credits

Optional credits are provided for regulatory purposes only to assist in complying with Queensland's 7-star standard for units. They do not extend the Nationwide House Energy Rating Scheme (NatHERS) star range beyond 10 stars.

A unit cannot be promoted as having more than 7 stars if those additional stars rely on optional credits for outdoor areas. For example, if a unit achieves a 7-star building shell rating, the inclusion of an outdoor living area with a fan does not increase its rating to 8 stars. The optional credits for units can only be used towards calculating the building's average rating for compliance purposes only.

Also consider...

Learn more about Queensland's climate zones for dwellings and buildings.
Learn more about the Nationwide House Energy Rating Scheme (NatHERS).
Read the National Construction Code for the construction of buildings.
Read about buying and renovating an apartment on the Australian Government's Your Home website.

Whole of Home assessment and score

From 1 May 2024, Modern Homes residential energy efficiency standards include:

a 7-star thermal performance rating for new houses and units
a Whole of Home score (out of 100) to assess the energy budget of the dwelling's major fixtures and appliances, including any solar photovoltaic (PV) energy system.

Whole of Home assessments aim to lower energy costs by helping homeowners make cost-effective choices about their home's major fixtures and appliances. Homeowners, designers and builders can explore the trade-offs and beneﬁts of different technologies and appliance efficiencies that works for them and their budget.

There are many appliance combinations that can be used to achieve a high Whole of Home score. An efficient water heating system (solar or heat pump) and appropriately-sized space heating or cooling systems can save money and ensure the home is comfortable and resilient in hot and cold climates. Inclusion of a solar PV energy system can also help offset the home's energy use.

The relationship between a home's thermal performance rating and its Whole of Home rating means that increasing thermal performance will increase the Whole of Home rating. This is because the heating and cooling energy needs will be lower in a home with a higher thermal performance rating.

What is included in a Whole of Home assessment

A Whole of Home assessment involves the following fixture and appliances:

artificial lighting
mechanical heating and cooling
hot water
swimming pool and spa pumps
cooking and plug-in appliances.

Onsite energy generation and storage (e.g. solar PV and battery) can also form part of a Whole of Home assessment where they are included in the design documentation.

Calculating a Whole of Home score

In simple terms, the assessment considers the energy used in a household for heating, cooling, appliances and equipment, minus any energy generated from solar PV. This assessment builds a useful snapshot of household energy costs as well as its carbon emissions.

Whole of Home ratings and requirements

The Whole of Home score ranges from 0 to 100 – a poor energy performing home would rate under 40, while a score of 100 is a net zero energy home. A score over 100 is possible where the home is producing more energy than it uses i.e. where it includes a large solar PV system.

A new house needs to achieve a minimum Whole of Home score of 60 (out of 100) and a new unit apartment needs to achieve at least 50 (out of 100).

Compliance options

The 2 main existing compliance options available to house energy assessors for Whole of Home assessments are:

NatHERS software

The same software tools used for thermal performance assessments are used for assessing compliance with the NCC Whole of Home energy efficiency requirements.

The following software tools have been accredited by NatHERS for use in performing Whole of Home assessments and issuing Whole of Home certificates:

BERS Pro
AccuRate Home
Home Energy Rating Optimisation (HERO)
FirstRate5.

NatHERS-accredited software is able to provide a whole of home rating for apartment units where hot water and space conditioning are self-contained in the unit, but currently does not offer a Whole of Home option for apartments with centralised services.

Deemed to Satisfy Elemental Provisions

This option provides a prescriptive approach to complying with the Whole of Home requirement. Following all the elemental provisions of the NCC creates a deemed to satisfy (DTS) solution.

The elemental provisions are provided in NCC 2022 as follows:

for houses – DTS Provisions of Volume Two, H6D2(2)(b)
for apartments – DTS Provisions of Volume One, J2D2(3)(a)(i), (b) and (c).

Whole of Home energy savings tips

The most important appliances affecting a Whole of Home assessment are heating/cooling and hot water, as on average they account for 40% and 23% of annual power demand, respectively.

Air-sourced heat pumps and air conditioners deliver 3 to 5 times more space heating or cooling energy than they consume in power and provide a major boost to a Whole of Home rating. This energy consumption outcome is similar for heat pump hot water systems.

A 5-watt LED lightbulb produces the same amount of light as a 75-watt incandescent lightbulb, while using 93% less energy, resulting in higher energy efficiency.

Also consider...

Learn more about the NatHERS Whole of Home rating to understand how it can be used to measure energy use.
See the Modern Homes provisions for more information and guidance materials
Read more about the National Construction Code 2022.