Residential energy efficiency standards

On 1 May 2024, the residential energy efficiency standards for new dwellings under the National Construction Code (NCC) 2022 commenced in Queensland. These standards have been implemented through an amendment to the Queensland Development Code 4.1 – Sustainable Buildings (PDF, 371.03 KB).

The changes improve the energy efficiency of the home's building shell, and for the first time, account for the energy usage of the household's major fixtures and appliances. Features like house orientation and better insulation may go unnoticed, but they make a positive difference to the home's energy performance and comfort.

These changes :

  • provide cost-of-living savings on energy bills over the life of the home
  • make homes more comfortable to live in
  • provide emissions reductions.

What this means

The home’s proposed design is typically assessed through either a software program or specifications under the NCC 2022.

New houses and units require:

  • 7-star (out of 10) energy equivalence rating for the building shell (roof, walls, windows and floors).
  • Whole of Home energy budget for the home’s major fixtures and appliances  (including air-conditioners, hot water heaters and artificial lighting), as well as any on-site renewable energy e.g. solar photovoltaic (PV) system.

7-star energy equivalence rating for new homes

The 7-star standard applies to all new houses and townhouses (class 1 buildings) and their attached, enclosed garage (class 10a buildings), and new units in an apartment building (class 2).

Units within an apartment building must collectively achieve an average of 7-stars for the whole building, with no individual unit to be less than 6-stars.

Building designers and architects can use a range of design styles and energy efficient features for the dwelling to comply with the 7-star standard.

Many energy-efficient (or ‘passive design’) features can be included at little or no extra cost, where possible, such as:

  • northern orientation of living areas and good room configuration to account for solar access and natural ventilation
  • minimising the area of east and west facing walls and windows
  • well-located and designed windows to capture breezes
  • shading of walls and windows with roof eaves, awnings and external blinds
  • treated glazing, like low-e glass or tinted, particularly for western facing windows
  • insulation in the roof space (e.g. reflective foil under roofing and batts above the ceiling) and to external walls
  • ventilating the roof space via roof and eave vents
  • lighter coloured roof and external walls to reflect heat
  • ceiling fans in living areas and bedrooms to promote air movement
  • well-designed outdoor living area (e.g. a deck or verandah with good orientation).

The region (climate zone) where a person lives will influence the energy efficiency features needed for compliance.

Homeowners should discuss how the 7-star standard applies to the proposed design of their new home and what features can be included with their building designer or architect, house energy assessor and building certifier early in the design stage.

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

Whole of Home energy budget

The residential energy efficiency standards also require a Whole of Home energy budget.  In simple terms, this considers the energy used in a household for heating, cooling, appliances and equipment, minus any energy generated from solar panels.

The Whole of Home energy budget 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, appliance efficiencies to create a home and appliance design that works for them and their budget.

The Whole of Home energy budget covers the following major fixtures and appliances:

  • Heating and cooling
  • Hot water
  • Artificial lighting
  • Swimming pool and spa pumps
  • Any onsite solar photovoltaic (PV) energy system.

The Whole of Home score is out of 100 – a poor energy performing home would rate under 40, while a score of 100 is a net zero energy value home.

For compliance, houses and townhouses (class 1 buildings) need to achieve a minimum score of 60 (out of 100) and new units a minimum score of 50 (out of 100).

There are many appliance combinations that can be used to achieve a high score for Whole of Home. An energy efficient hot water system (like solar or heat pump) and appropriately-sized air conditioning system, can save money and ensure the home is comfortable and resilient in hot and cold climates. On-site renewable energy generation can also help off-set the home’s energy use.

The relationship between a home’s building shell rating and its Whole of Home assessment means that increasing building shell rating can increase the Whole of Home score.  This is because the heating and cooling energy needs will be lower in a home with a higher building shell rating.

Assessing residential energy efficiency compliance

There are typically two compliance options available to house energy assessors to assess the home’s compliance to the residential energy efficiency standard. These are:

NatHERS software

This compliance pathway uses a software tool approved by the Nationwide House Energy Rating Scheme (NatHERS). The software assesses the proposed design of the dwelling’s building shell and generates a star rating 9out of 10). It also assesses for its Whole of Home energy budget.

There are four NatHERS software tools available for use:

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

Upon completion of the assessment, the software tool will issue a NatHERS Certificate which indicates the star rating for the design and a Whole of Home score.

Deemed to Satisfy Elemental Provisions

This compliance pathway is a more prescriptive approach using the NCC specific deemed-to-satisfy (DtS) provisions for the dwelling’s building shell. A separate Whole of Home calculator is used to show if it passes or fails.

This compliance option is prescribed as follows:

  • for houses in the DtS Provisions of NCC 2022 Volume Two, Part H6 Energy efficiency – H6D2(1)(b) and H6D2(2)(b)
  • for apartments in the DtS Provisions of NCC 2022 Volume One,  Part J2 Energy efficiency – J2D2(2)(b) and J2D2(3)(a)(i), (b) and (c).

Impact

For a new home in Queensland, the residential energy efficiency standards will provide an average electricity saving of $185 per year across Queensland’s 4 climate zones.

The Australian Building Codes Board (ABCB) commissioned an independent analysis for jurisdictions to transition to the new standards from 2019 to 2022. The former Department of Energy and Public Works also commissioned a cost-benefit analysis to investigate the impacts for Queensland of adopting the NCC 2022 residential energy efficiency standards (given Queensland had a lower standard than the national standard at that time). This analysis identified a net benefit of at least $506 million for the Queensland community.

The standards are estimated to reduce emissions by 4.63 million tonnes.

More information

For more information about the NCC 2022, visit the ABCB website.