Energy Modelling

J1V3 is the performance pathway under NCC Section J (Volume 1) for Class 3-9 commercial and multi-residential buildings. NatHERS is the residential rating scheme for Class 1 houses, townhouses and Class 2 apartments. The two pathways serve completely different building classes, use different software (IES VE for J1V3, HERO for NatHERS), and have different benchmarks. Mixed-use buildings with both residential and commercial components often require both.

If your building is a detached house, townhouse or apartment (Class 1 or Class 2), NatHERS applies. If your building is commercial, retail, industrial, hospitality, healthcare, education or Class 3 (serviced apartments), NCC Section J / J1V3 applies. Mixed-use buildings often require both pathways. Ark Resources can advise on the correct pathway for your specific building class and project type.

Yes, if your building is Class 3, 5, 6, 7, 8 or 9 under the NCC, Section J energy compliance is mandatory for a building permit. Section J compliance can be achieved via the Deemed-to-Satisfy (DTS) pathway using prescriptive requirements, or via the J1V3 performance pathway using whole-building energy simulation. Ark Resources can advise on the most appropriate pathway for your project.

Ideally at schematic or DA stage, before facade and HVAC decisions are locked in. Early engagement allows the compliance pathway to inform glazing ratios, insulation levels and mechanical system selection rather than simply validate them. For J1V3 performance solutions, early modelling can identify compliant design options that would not be achievable under the DTS prescriptive pathway.

Section J does not apply to Class 1 houses, townhouses or Class 2 apartments. Those building classes are assessed under NatHERS using the HERO software tool. However, Class 3 buildings (serviced apartments and hotels) are assessed under Section J, not NatHERS. Mixed-use developments with both Class 2 apartments and commercial tenancies often require both NatHERS and Section J assessments.

Ark Resources uses IES VE for whole-building energy simulation, including J1V3 Section J compliance, NABERS Design for Performance and Green Star energy credits. HERO is used for NatHERS residential thermal performance ratings. Our models are built to the level of detail required by the target compliance pathway.

A J1V3 model needs to capture building geometry, orientation, envelope thermal properties, glazing performance, HVAC system type and lighting loads. The level of detail increases as design develops. Ark Resources scopes the model to match the compliance requirement and updates iteratively as the design progresses. Where available, we request IFC models and work closely with your team throughout to confirm all inputs are captured accurately. We can commence with outline documentation at early design stage.

We require architectural drawings including floor plans, elevations and sections. We do not require a glazing schedule, insulation levels or a mechanical services brief to commence. We determine the glazing values and insulation R-values required to achieve compliance and provide these back to the design team as outputs rather than inputs. Mechanical services are generally not modelled as part of a J1V3 assessment. We can commence at schematic design stage and refine the model as the design develops.

Yes. J1V3 is a Verification Method included in the NCC and is accepted by registered building surveyors across all Australian states and territories. The modelling software must be an accredited tool. Ark Resources uses IES VE, which is widely accepted for J1V3 performance solutions.

Yes. Green Star Buildings requires energy modelling to demonstrate performance against energy and emissions credits. Ark Resources integrates Green Star energy modelling with J1V3 compliance where both are required, reducing overall cost and effort by coordinating across both frameworks from a single IES VE model.