Solar PV is now mandatory. EV charging infrastructure is now mandatory. Facade U-values have tightened. Here is what changes under Section J from 1 May 2027 and what to address before your next CC lodgement.
NCC 2025 was published on 1 June 2026. For commercial buildings in NSW, it applies to projects with a CC lodgement date on or after 1 May 2027, confirmed by NSW Ministerial release. Until then, NCC 2022 Amendment 2 governs all commercial Section J assessments. Always confirm the lodgement date in writing from the certifier before selecting which code version applies.
The changes are material. Architects, builders and surveyors designing for 2027 lodgement should understand what is coming well in advance.
NCC 2022 treated on-site solar PV as a JV3 reference building concept, something modellers accounted for, not something DTS clients had to specify. NCC 2025 changes that entirely.
J9D5 now applies to all commercial buildings on the DTS pathway. Buildings must cover 100% of eligible roof area with solar PV, or achieve a minimum peak output relative to conditioned floor area. For a Class 5 or Class 6 building in Sydney (Climate Zone 5), the minimum is 65 Wp per m² of conditioned space. Buildings using gas for services face an additional PV requirement on top of this.
The only exemptions are where 100% of the eligible roof area is shaded more than 70% of annual daylight hours, or where an equivalent renewable generation system is provided.
J9D4 applies to all carparks in Class 3, 5, 6, 7b, 8, and 9 buildings. This is not a requirement to install chargers. It is a requirement to install the electrical distribution boards and capacity to support them. For a Class 5 or Class 6 office building, boards must be sized to support a 7 kW Type 2 charger in 10% of spaces. For Class 3, 7b, 8 and 9, the figure is 20% of spaces. Standalone Class 7a car parks are excluded.
Both requirements add to project cost and require early coordination with electrical engineers. They are not optional. DTS compliance cannot be achieved without them from 1 May 2027.
The minimum total R-value remains R3.7 downward for Class 5, 6, 7 and 8 in Climate Zone 5, but NCC 2025 adds a new condition for solar reflectance. Bare aluminium roofing, common in industrial and warehouse projects, no longer satisfies the solar absorptance limit on its own. Thermal emittance of at least 0.85 is now mandatory alongside the absorptance requirement. Aluminium has an emittance of approximately 0.05 and will not comply unless it achieves Total Solar Reflectance above 0.55 or a Solar Reflectance Index above 61 independently.
The total system U-value limit, which governs the combined performance of opaque wall and glazing together, is now climate-zone dependent rather than a flat U2.0 across all zones. For a Class 5 office in Climate Zone 5, the limit tightens from U2.0 to U1.9. Opaque wall R-values have been substantially revised and are generally tighter, particularly in Climate Zones 3, 7 and 8. Solar admittance limits have been simplified to a uniform value across CZ1 to CZ7, previously a per-zone lookup, with tighter thresholds for glazing-heavy facades.
These changes are most relevant to projects with high glazing ratios where the DTS facade calculator previously allowed more flexibility. Glazing specifications that passed under NCC 2022 may no longer pass under NCC 2025 without adjustment.
Projects using the performance pathway face additional changes under NCC 2025.
The reference building now includes a modelled solar PV system per J9D5, with the same minimum output as the DTS requirement. This changes the energy budget the proposed building must beat and means modellers need to account for PV generation in both models.
Standard TMY EPW files used under NCC 2022 may not satisfy this requirement. Confirm with the certifier whether suitable updated weather files are available before commencing NCC 2025 JV3 modelling. This is currently an open question with no definitive resolution from ABCB at time of writing.
In addition to the national JV3 requirement, NSW projects must comply with Specification 48, which requires a zone-by-zone peak load comparison between the proposed and reference buildings. Any zone with a 98th percentile peak heating load of 10 W/m² or above, or a cooling load of 40 W/m² or above, is assessable and must be individually documented. This adds a meaningful step to the reporting process.
The NSW GHG compliance threshold also tightens: the proposed building must achieve 97% or less of reference building GHG emissions. The national threshold is 100%.
Section J addresses operational energy: the energy consumed by a building's HVAC, lighting, hot water and other services during its working life. NCC 2025 does not introduce mandatory embodied carbon requirements for commercial buildings.
However, embodied carbon is increasingly appearing as a project requirement through other channels. Green Star and NABERS Embodied Carbon assessments are being required on larger commercial projects, particularly where institutional investors or government agencies are involved. Some state and local planning overlays are beginning to require Life Cycle Assessment documentation as a condition of consent.
This is a separate scope of work from Section J, assessed using different methodologies and benchmarks. If your project has a Green Star target or a sustainability condition in the DA, confirm whether an embodied carbon assessment is required before the construction certificate stage. It is generally easier and less costly to address this upfront than as a post-approval variation.
NCC 2022 still governs until 1 May 2027. For projects already in design, there is no obligation to meet NCC 2025 requirements ahead of that date. But for larger projects with longer lead times, early awareness avoids costly changes closer to lodgement.
NCC version is determined by CC lodgement date, not design date or construction start. Always confirm the applicable version in writing from the certifier before commencing a Section J assessment.
We prepare Section J DTS and JV3 reports for Class 5 to 9 commercial buildings in NSW. Fixed-fee, fast turnaround. Contact us to discuss your project.
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