NCC 2022 Section J Overview: What Changed

What You Need to Know

NCC 2022 rewrote the energy efficiency rules for commercial buildings in Australia. Section J covers every building from Class 3 to Class 9 - offices, shops, hotels, warehouses, hospitals, schools, and more. The 2022 update added 3 new performance requirements, tightened the building envelope rules, and introduced mandatory provisions for solar panels and electric vehicle charging. If you lodge a DA or CC after 1 October 2023, you must comply with NCC 2022 Section J.

• J1P1 sets the energy use limits for commercial buildings and common areas of Class 2 apartment buildings. It no longer covers individual apartments - they now have their own rules. (NCC 2022, Part J1)
• J1P2 (new) requires the thermal performance of each apartment (Class 2 sole-occupancy unit) or Class 4 dwelling to meet a 7-star NatHERS equivalent. (NCC 2022, J1P2)
• J1P3 (new) caps the annual energy budget for each Class 2 apartment and Class 4 dwelling. This is a whole-of-unit energy limit, not just heating and cooling. (NCC 2022, J1P3)
• J1P4 (new) requires buildings to include provisions for future solar panels, battery storage, and EV charging. At least 20% of roof area must be kept clear for solar PV. The main switchboard must have at least 2 empty three-phase circuit breaker slots and 4 DIN rail spaces labelled for solar and battery systems. (NCC 2022, J1P4, J9D5)
• EV charging readiness is mandatory for car parks in Class 2, 3, 5, 6, 7b, 8, and 9 buildings. Each storey needs a dedicated electrical distribution board labelled for EV charging, plus space for individual sub-circuit metering. (NCC 2022, J9D4)
• Walls and windows are now assessed together as a single “facade” unit. Each element must still meet its own minimum, but the combined performance must also hit a collective standard. (NCC 2022, Part J4)
• Thermal bridging calculations are more detailed. Steel studs, shelf angles, and other penetrations through insulation must be properly accounted for in the building envelope. (NCC 2022, Part J4)
• Energy modelling software must comply with ANSI/ASHRAE Standard 140. This means EnergyPlus or equivalent validated software. NatHERS software is not permitted for commercial building modelling. (NCC 2022, J1V3)
• The NABERS pathway (J1V1) has expanded. It now covers Class 2 common areas, Class 3 buildings, and Class 6 shopping centres - not just Class 5 offices. A minimum 5.5-star Commitment Agreement is required. (NCC 2022, J1V1)
• Sub-slab insulation for slabs on ground is no longer required for smaller buildings under DtS, removing a cost barrier that pushed many projects to J1V3. (NCC 2022, Part J4)
• DTS construction properties (such as R-values for reflective airspaces in walls) that went missing in NCC 2019 have been re-inserted into NCC 2022. (NCC 2022, Part J4)

Take a 3,000 m² Class 5 office building with a glazed north facade. Under NCC 2019, you could check the walls and windows separately against the prescriptive tables. Now you must assess them together as a facade. If the glazing has a high solar heat gain coefficient, you need to compensate with better wall insulation or external shading - the combined result must pass.

The new thermal bridging rules mean your insulation schedule needs more detail. A steel-framed wall with R-2.5 batt insulation does not actually deliver R-2.5 in practice - steel studs at 600 mm centres can cut the effective R-value by 40% or more. NCC 2022 demands you account for this in your calculations.

For developers, the solar and EV provisions add upfront costs but are modest. Keeping 20% of the roof clear for solar panels mostly means planning the roof layout properly. The switchboard provisions (2 circuit breaker slots and 4 DIN rail spaces) cost under $500 to include at construction but would cost thousands to retrofit later.

The expanded NABERS pathway is good news for large projects. If you already plan a NABERS Commitment Agreement for a Class 5 office, the same approach now works for Class 3 hotels and Class 6 retail centres.