QLD residential energy efficiency under QDC 4.1 and NCC 2022

What it is

Queensland adopted the NCC 2022 residential energy efficiency provisions on 1 May 2024 through the Queensland Development Code Part 4.1 (Sustainable Buildings). QDC 4.1 is the state level variation that sits over the National Construction Code Volume Two for Class 1 buildings and the residential parts of Volume One for Class 2 and 4 apartments. For a residential builder this means every new house DA lodged from 1 May 2024 must meet the 7 star shell rating plus the Whole of Home score.

This is the largest single bump in residential energy compliance Queensland has seen. The 2019 baseline was 6 stars under NCC 2019. The 2024 rules add a star to the shell and bring in a brand new Whole of Home framework that measures the energy budget of fixed appliances.

The two tests

NCC 2022 Volume Two Part 13 sets two separate residential energy tests. A new house has to pass both.

7 star NatHERS shell rating

The first test is a 7 star (out of 10) energy equivalence rating of the building shell. This is the NatHERS modelling most QLD builders already do, run on accredited software (FirstRate5, BERS Pro, AccuRate). The score reflects how much heating and cooling energy the shell uses across a NatHERS climate zone. Brisbane sits in NatHERS climate zone 10 and the Gold Coast in climate zone 10 as well. Townsville is climate zone 3.

In practice 7 stars in southeast Queensland forces:

• Higher performance glazing across north and west elevations
• Insulation in external walls (R2.0 or higher in most south east QLD designs)
• Ceiling insulation up to R5.0 in many cases
• Ceiling fans counted as a cooling aid in living areas and bedrooms

Whole of Home score

The second test is a Whole of Home score (out of 100). This measures the energy budget of the major fixed appliances and any onsite PV system. Heating, cooling, hot water, plug loads and lighting all count. A rooftop PV system can lift the score. The threshold passes are climate zone specific. Brisbane is set at 60 for a freestanding house with no PV. With a typical 6.6 kW PV the score lifts comfortably past 90.

QLD specific variations under QDC 4.1

QDC 4.1 is not a clean adoption of NCC 2022. The state made three substantive changes:

What QDC 4.1 removed

QDC 4.1 removed the optional Queensland PV credit (a builder could previously satisfy the energy rules by installing PV instead of meeting a higher shell rating). It also removed the 2009 version glazing calculator option. From 1 May 2024 these workarounds are gone. The 7 star shell is mandatory.

What QDC 4.1 retained

QDC 4.1 retained the optional one star credit for outdoor living areas on new houses. A compliant outdoor living area gives a star towards the shell rating, which lets the designer trade off slightly less glazing performance or insulation in the rest of the building. QDC 4.1 also extends the outdoor living credit state wide for new apartment buildings, which is new.

Transitional arrangements

There was a 12 month transitional window where a DA lodged before 1 May 2024 could be assessed against NCC 2019 rules. That window has now closed. Every new residential DA in Queensland is assessed under NCC 2022 plus QDC 4.1.

What this means for a residential builder

The biggest practical change is the design stage. A 6 star plan does not pass the 7 star test by tweaking glazing alone. The energy assessor needs to be in the design loop at sketch stage, not at DA submission stage. Builders who learned the 2019 rules by trial and error are seeing 5 to 15 per cent build cost lift on the shell, depending on orientation.

Where TradeLens fits

TradeLens flags residential project files where the energy report is more than 12 months old, where the Whole of Home assessment is missing, or where the design relies on the old PV credit that QDC 4.1 removed. The pattern most likely to trip a builder is using a 2023 energy report on a 2026 build.

Common mistakes

• Submitting a NCC 2019 era 6 star energy report on a 2026 DA. It will not pass
• Assuming a PV system alone meets the shell requirement. The shell still has to be 7 stars on the modelling
• Forgetting to claim the outdoor living one star credit when the design supports it
• Letting the energy assessor design the windows without the builder confirming sashes and frames are quotable from a local supplier

The energy rules are tight enough that they reshape the design. Catching them at the brief stage is much cheaper than catching them at lockup.