Commercial Energy Compliance
Clear guidance on J1V3 reference-building modelling and whole-building Performance Solutions under NCC Section J.
For architects, developers, builders and consultants seeking to understand how proposed and reference buildings are compared, what information informs the model and how JV3 sits within the broader commercial energy-efficiency framework.
Send Your Plans for ReviewIn Brief
JV3 is the commonly used industry term for a reference-building Verification Method within the National Construction Code. Under applicable NCC editions, it may be formally referenced as J1V3.
The method supports a Performance Solution by comparing the modelled energy performance of a proposed commercial building with a reference building based on the applicable Deemed-to-Satisfy provisions. It sits within the broader Section J framework rather than operating as a separate form of compliance.
The comparison considers the building as an interconnected system. Geometry, orientation, climate, shading, envelope construction, glazing, occupancy assumptions, operating schedules and relevant building services can all influence the modelled outcome.
JV3 can allow design alternatives to be tested through whole-building modelling, but the proposed building must still satisfy the applicable performance criteria, safeguards and documentation requirements. The decision to use JV3 should therefore be based on the project design and compliance strategy, not on flexibility alone.
The proposed building is modelled and compared with a reference building established using the applicable NCC provisions.
The assessment considers how the envelope, glazing, climate, shading, schedules and relevant services interact across the building.
JV3 may support a Performance Solution within Section J. For pathway-selection guidance, read the DTS and JV3 comparison.
Knowledge Navigation
Use this Knowledge Hub to understand how JV3 and J1V3 reference-building modelling works, what information shapes the models, how performance is compared and why the applicable NCC edition and project documentation matter.
Start Here
Understand what JV3 means, why it may be formally referenced as J1V3 and how the Verification Method sits within the broader Section J framework.
Model Structure
Explore the two models at the centre of JV3 and how the proposed design is compared with an NCC-defined reference building.
Model Scope
Review how geometry, orientation, climate, shading, envelope construction, glazing, schedules and relevant services shape the modelled outcome.
Model Definition
Learn how zoning, occupancy, operating schedules, internal loads, systems data and interim assumptions affect the reliability of the assessment.
Performance Verification
See how the proposed-building result is assessed against the reference-building benchmark under controlled and comparable modelling conditions.
Additional Criteria
Understand why a favourable whole-building comparison does not remove separate envelope-performance and thermal-condition requirements.
Regulatory Context
Understand why project location, approval timing, jurisdictional adoption and the applicable NCC edition must be confirmed before modelling begins.
NCC 2025
Review the revised performance margin, envelope comparison, thermal-condition pathways, climate inputs, operating profiles and solar context.
Project Preparation
Review the drawings, façade information, construction specifications, schedules and building-services inputs required for a coordinated JV3 model.
JV3 Explained
JV3 is not separate from Section J. Section J is the broader NCC framework that establishes energy-efficiency requirements for relevant commercial and non-residential buildings.
Projects may address those requirements by following the Deemed-to-Satisfy provisions or by developing a Performance Solution. JV3 is the commonly used industry name for a reference-building Verification Method that may be used as part of that Performance Solution. Under applicable NCC editions, the method is formally referenced as J1V3.
Rather than replacing Section J, the method provides a structured way to demonstrate that the proposed building satisfies the relevant Performance Requirements through comparative energy modelling. The assessment must follow the requirements, modelling conditions and safeguards associated with the applicable NCC edition.
The Framework
Establishes the commercial building energy-efficiency Performance Requirements and associated compliance provisions within NCC Volume One.
The Prescribed Response
Provides prescribed provisions for relevant aspects of the building envelope and services. A project following these provisions can use the DTS pathway directly.
The Verification Method
Uses proposed-building and reference-building models to provide evidence that a Performance Solution achieves the required energy-performance outcome.
This Knowledge Hub focuses on how the JV3 modelling method works. For a fuller comparison of design flexibility, project suitability and pathway selection, read Section J DTS vs JV3.
Reference-Building Modelling
The central principle of JV3 modelling is comparison. Two building models are developed under the applicable Verification Method: one representing the proposed design and another representing an NCC-based reference building.
The proposed-building model reflects the project being assessed, including its geometry, orientation, envelope construction, glazing, shading, zoning and relevant building services. The reference-building model establishes the compliance benchmark using the characteristics and modelling rules prescribed by the applicable NCC edition.
Both models are assessed under controlled and comparable conditions. This allows the modelling outcome to show whether the proposed design achieves the required performance relative to the reference building, rather than comparing two unrelated design scenarios.
The Project Design
Represents the building as it is intended to be documented and constructed.
Actual building geometry and orientation
Proposed walls, roofs, floors and insulation
Proposed glazing, framing and shading
Defined thermal zones and space uses
Relevant proposed services and controls
The Compliance Benchmark
Provides the benchmark against which the proposed design is assessed.
Configured using the applicable NCC methodology
Uses prescribed envelope and glazing characteristics
Applies the required reference-building assumptions
Uses comparable climate and operating conditions
Establishes the required performance benchmark
| Model component | Proposed building | Reference building |
|---|---|---|
| Purpose | Represents the actual project design being assessed. | Establishes the NCC-based performance benchmark. |
| Design properties | Uses the proposed envelope, glazing, shading and relevant services information. | Uses the characteristics required by the applicable Verification Method. |
| Operating conditions | Modelled using the required schedules, loads and assumptions for the proposed design. | Modelled under corresponding conditions so the comparison remains meaningful. |
| Outcome | Produces the modelled performance of the proposed building. | Produces the benchmark result against which the proposed building is tested. |
The reference building is not an optional design alternative created by the modeller. Its characteristics are determined by the applicable NCC provisions so that the proposed building can be assessed against a consistent compliance benchmark.
The comparison is also subject to applicable performance criteria and safeguards. The next sections explain the inputs and assumptions used to build the models and how the resulting performance comparison is interpreted.
Whole-Building Model
JV3 modelling assesses the energy performance of the proposed building as an interconnected system. The model considers how the building form, envelope, glazing, climate, operating conditions and relevant services interact rather than reviewing each element as an isolated compliance item.
The assessment is based on a comparison between the proposed building and an NCC-defined reference building. Consistent modelling conditions are used so the effect of the proposed design can be evaluated against the performance benchmark established by the applicable Verification Method.
The precise modelling scope depends on the building classification, applicable NCC edition, project design and Performance Solution strategy. Not every project will involve the same systems, zones or technical inputs.
Building Form
The model represents the building form, floor areas, orientation, conditioned zones and the relationship between internal spaces and the external environment.
Building Envelope
Construction build-ups, insulation, thermal transmittance, exposed surfaces and other relevant envelope properties influence heating and cooling demand.
Façade Performance
Glazing area, thermal performance, solar heat gain, frame properties, façade orientation and fixed shading can materially affect the modelled result.
External Conditions
The applicable weather data, solar exposure and surrounding shading conditions help define how the building responds to its location throughout the modelled year.
Building Operation
Occupancy patterns, operating hours, equipment loads, lighting use and other internal conditions are represented in accordance with the applicable modelling methodology.
Building Services
Relevant air-conditioning, ventilation, lighting, heated-water and other regulated systems may form part of the proposed and reference building comparison.
JV3 can recognise interactions between different parts of the design, but it does not mean that any underperforming element can automatically be offset elsewhere. The proposed building must still satisfy the performance comparison and any applicable envelope, comfort or other safeguards required by the Verification Method.
The quality of the outcome depends on the reliability of the information used to construct the model. Zoning, schedules, technical properties and assumptions are therefore addressed separately in the modelling inputs and assumptions section.
Model Definition
A JV3 result depends on the information used to define the proposed and reference buildings. Geometry, thermal zoning, envelope properties, glazing, operating schedules, internal loads and relevant building services all influence how the models behave.
Some inputs are determined by the applicable Verification Method. Others must reflect the project as designed. Where information is not yet confirmed, an interim assumption may be required so the model can progress, but that assumption should be identified clearly and reviewed once coordinated information becomes available.
The objective is not simply to populate the software. Each input should have a clear source, a defined purpose and a consistent relationship with the drawings, schedules, specifications and Performance Solution documentation.
Model Structure
The model should represent the building form, orientation, floor areas, envelope surfaces and conditioned spaces. Thermal zones are defined to reflect differences in use, exposure, schedules and servicing conditions.
Building Fabric
Wall, roof and floor constructions are represented using the relevant thermal properties, insulation arrangements and material build-ups associated with the proposed design and reference-building methodology.
Façade Inputs
Glazing area, thermal transmittance, solar heat gain, frame performance, façade orientation and fixed shading should reflect the coordinated façade design rather than generic values where project-specific information is available.
Operating Conditions
Occupancy levels, operating hours and space-use schedules influence internal heat gains and the timing of heating, cooling, ventilation and lighting demand.
Internal Conditions
Lighting power, equipment loads and other internal gains are assigned using the applicable modelling methodology and any project-specific conditions that form part of the assessment.
Building Services
Relevant mechanical, ventilation, lighting, heated-water and control-system inputs are represented in accordance with the proposed design and the corresponding reference-building rules.
| Input type | How it is established | How it should be managed |
|---|---|---|
| NCC-prescribed inputs | Defined by the applicable Verification Method, reference-building rules or associated modelling methodology. | Applied consistently and not replaced by preferred project assumptions unless the methodology permits it. |
| Project-specific inputs | Taken from coordinated drawings, specifications, schedules, consultant information and confirmed design decisions. | Checked against the final documentation so the proposed model represents the building being approved and constructed. |
| Interim assumptions | Used where required information has not yet been finalised but the model needs to progress. | Recorded clearly, communicated to the project team and replaced or confirmed before the assessment is finalised. |
| Revised inputs | Arise when the design, façade, construction, zoning, operation or services strategy changes. | Reviewed for material impact and incorporated into the model and supporting documentation where required. |
An assumption is not necessarily a modelling error. During design development, some information may legitimately remain unresolved. The risk arises when an assumption is treated as confirmed information or is not revisited after the design changes.
A clear assumptions register can help the project team understand which values are prescribed, which have been supplied by consultants and which still require confirmation. This supports traceability and reduces inconsistency between the model and the project documents.
Once the models and their inputs have been established, the proposed-building result can be assessed against the reference-building benchmark. The next section explains how the JV3 performance comparison works.
Performance Verification
Once the proposed and reference models have been defined, their results are compared using the criteria established by the applicable Verification Method. The purpose is to determine whether the proposed building achieves the required performance relative to the NCC-defined benchmark.
The comparison must be controlled. Climate data, operating conditions, internal loads and other required assumptions are applied consistently so that the outcome reflects meaningful differences between the proposed design and the reference-building configuration.
A favourable comparison is important, but it is not the only consideration. The assessment must also follow the required modelling methodology and address any additional envelope, thermal-comfort or other safeguards associated with the relevant NCC edition.
Step 01
The reference building is configured using the prescribed rules and assumptions that establish the applicable compliance benchmark.
Step 02
The proposed model represents the coordinated building design, including its envelope, glazing, shading, zoning and relevant services.
Step 03
The relevant modelled energy-use result or other required performance metric is assessed against the reference-building outcome.
Step 04
The result is reviewed together with any separate envelope, comfort or other criteria required by the applicable Verification Method.
| Comparison element | What remains comparable | What may differ |
|---|---|---|
| Location and climate | The models use the required project location, weather data and corresponding external conditions. | The proposed design may respond differently because of its envelope, glazing, shading and services. |
| Building operation | Required occupancy, schedules, internal loads and operating conditions are applied on a consistent basis. | Design-specific systems and controls may alter the energy needed to serve those operating conditions. |
| Envelope and façade | Both models represent the building geometry in accordance with the applicable modelling rules. | The proposed building uses the documented construction, glazing and shading, while the reference building uses prescribed benchmark characteristics. |
| Performance outcome | Both models are assessed using the metric and calculation procedure required by the Verification Method. | Their results differ according to the performance of the proposed design relative to the reference-building benchmark. |
The reference-building result is governed by the applicable NCC methodology. It should not be adjusted selectively to make the proposed design appear more favourable. The validity of the comparison depends on both models being prepared consistently and transparently.
Where the proposed building does not achieve the required outcome, the project team may review design variables and update the model. Revised results must still be based on a coordinated and technically supportable design.
The next section explains why a satisfactory whole-building comparison does not remove the need to address applicable envelope safeguards and thermal-comfort criteria.
Additional Performance Criteria
A satisfactory proposed-versus-reference energy comparison does not necessarily complete the JV3 assessment. The applicable Verification Method may also require separate checks intended to protect the performance of the building envelope and maintain acceptable internal comfort conditions.
These safeguards limit the extent to which efficient building services or favourable performance in one part of the design can compensate for weaknesses elsewhere. They help ensure that the proposed building does not achieve the required whole-building result while relying on an envelope or internal environment that performs unacceptably.
The exact criteria depend on the applicable NCC edition, building classification and modelling methodology. They should therefore be confirmed before modelling assumptions, design options or performance targets are finalised.
Envelope Performance
The building envelope influences heating and cooling demand before mechanical systems are considered. Safeguards may therefore require the proposed envelope to remain within a defined level of performance relative to the applicable benchmark.
Relevant factors can include opaque-envelope construction, insulation, glazing, solar heat gain, façade orientation, shading and the interaction between different envelope elements.
Internal Conditions
Thermal-comfort criteria examine whether occupied spaces are expected to maintain suitable internal conditions under the required modelling assumptions.
The assessment may consider room or zone conditions, occupied periods, internal loads, solar exposure, glazing, envelope response and system operation in accordance with the relevant Verification Method.
| Assessment layer | What it examines | Why it remains separate |
|---|---|---|
| Whole-building comparison | Compares the modelled performance of the proposed building with the reference-building benchmark. | It establishes the principal energy-performance outcome but may not reveal unacceptable performance within an individual element or occupied zone. |
| Envelope safeguard | Reviews the performance of the façade, glazing and opaque building fabric against the applicable criterion. | It helps prevent an inefficient envelope from being offset solely through higher-performing services or other energy measures. |
| Thermal-comfort assessment | Reviews internal conditions within relevant occupied spaces or zones under the required modelling conditions. | A building can achieve an aggregate energy result while individual spaces still experience undesirable temperature or comfort conditions. |
JV3 can allow the interactions between façade design, building fabric, glazing and services to be assessed together. It does not create unrestricted permission to weaken one part of the design because another part performs well.
Where an envelope or thermal-comfort criterion is not achieved, the relevant design inputs should be reviewed. This may involve changes to glazing, shading, insulation, construction, zoning, internal loads or system operation, depending on the source of the result.
Any resulting design revision should be incorporated into the model and coordinated project documents. The next section explains how design iteration and model alignment are managed as the project develops.
Design Development
JV3 modelling is often iterative. An initial performance comparison may identify parts of the proposed design that require further review before the building satisfies the applicable energy, envelope or thermal-comfort criteria.
The project team can then test coordinated revisions to glazing, shading, insulation, façade construction, zoning, internal loads or building services. Each revision should represent a design decision that can be documented and delivered, rather than an isolated modelling adjustment.
The final model, Performance Solution report, drawings, schedules and specifications should describe the same building. Maintaining that alignment is essential because a compliant model does not remain representative when material project changes are made without review.
Review the Result
The modelling outcome is reviewed to understand which façades, zones, loads, systems or assumptions are materially influencing the whole-building comparison or an additional safeguard.
Coordinate Options
Potential changes should be developed with the relevant architects, façade consultants, services engineers and other project participants so the revised inputs remain technically and commercially realistic.
Update the Model
Confirmed changes are incorporated into the proposed-building model. Related geometry, construction, glazing, schedules, zoning or services inputs should also be checked for consequential effects.
Repeat the Comparison
The revised proposed building is compared again with the reference-building benchmark and checked against any applicable envelope, comfort or other criteria.
Document the Outcome
The final modelling inputs, assumptions, performance results and design requirements should be clearly reflected in the supporting Performance Solution documentation.
Maintain Alignment
Subsequent changes to the approved or documented design should be screened for modelling impact before procurement, certification or construction proceeds.
| Possible revision | Potential modelling effect | Coordination required |
|---|---|---|
| Glazing or frame change | Can alter heat transfer, solar gain, comfort conditions and heating or cooling demand. | Update glazing schedules, façade documentation, specifications and the proposed-building model. |
| Shading or façade revision | Can change solar exposure, daylight interaction and zone-level thermal conditions. | Coordinate elevations, sections, façade details and model geometry. |
| Envelope construction change | Can affect thermal transmittance, heating and cooling demand and envelope safeguards. | Update construction details, insulation specifications and relevant model assemblies. |
| Space-use or zoning change | Can alter occupancy, schedules, internal loads, conditioning and ventilation assumptions. | Review plans, classifications, operational information and thermal-zone definitions. |
| Building-services revision | Can affect regulated energy use, system efficiencies, controls and whole-building performance. | Coordinate mechanical, ventilation, lighting or heated-water documentation with the model. |
JV3 modelling is most useful when it supports coordinated design development. It should not become a separate technical exercise that progresses independently from architectural, façade, services and construction decisions.
A clear record of model revisions, assumptions and confirmed design inputs helps preserve traceability. It also makes it easier to identify whether a later substitution or documentation change affects the approved performance outcome.
Before the modelling basis is finalised, the project team should also confirm the code framework governing the assessment. The next section explains how the applicable NCC edition and jurisdiction influence the JV3 methodology.
Regulatory Context
JV3 modelling must be prepared against the National Construction Code provisions that legally apply to the project. Although the NCC is developed nationally, it is given legal effect through state and territory legislation, and adoption dates, transition arrangements and local variations can differ between jurisdictions.
The latest published NCC edition is therefore not automatically the edition governing every project. The relevant edition may depend on the project location, approval pathway, application or design milestones and any transition provisions established by the jurisdiction.
The modelling basis should be confirmed before the proposed and reference buildings are finalised. Changes between NCC editions can affect terminology, reference-building rules, weather data, performance criteria, safeguards and the evidence required to support the Performance Solution.
Project Location
The project location determines which building legislation gives the NCC legal effect and which jurisdictional variations, additions or administrative requirements may apply.
Code Edition
The assessment should identify the complete NCC edition being applied, including any relevant amendments, referenced standards and associated jurisdictional provisions.
Project Milestones
Relevant application, design, approval or commencement dates may determine whether a current edition, a previous edition or a jurisdiction-specific transition arrangement governs the project.
Building Scope
Building classifications, mixed-use areas, additions, alterations and the extent of new building work can influence which energy-efficiency provisions form part of the assessment scope.
Local Provisions
A nationally published clause may be varied, supplemented or administered differently within a particular state or territory. These provisions should be checked alongside the national NCC text.
Approval Coordination
The nominated NCC edition and Performance Solution scope should be coordinated with the relevant certifier, building surveyor or approval authority before the assessment is finalised.
| Question to confirm | Why it matters | Where it affects the assessment |
|---|---|---|
| Where is the project located? | The jurisdiction determines adoption timing, local legislation and any state or territory variations. | Code references, climate inputs, local provisions and approval documentation. |
| Which NCC edition is nominated? | Different editions can contain different modelling rules, reference-building provisions and additional criteria. | Proposed and reference models, performance comparison, safeguards and report structure. |
| Do transition provisions apply? | A jurisdiction may permit eligible projects to continue under an earlier edition for a defined period or based on specified milestones. | The complete technical basis on which the JV3 assessment is prepared. |
| Are local variations relevant? | Jurisdictional variations or additions may modify how a national provision applies to the project. | Performance Solution scope, technical evidence and approval coordination. |
The model, calculations and report should identify the NCC edition, amendment status, jurisdiction and relevant Verification Method being applied. References from different editions should not be combined informally, because the associated assumptions and criteria may not be equivalent.
Where the project programme spans a code transition, the nominated basis should remain visible across consultant briefs, modelling inputs, Performance Solution documentation and approval correspondence.
The next section examines the principal NCC 2025 changes affecting J1V3 modelling and why projects moving between editions may require a different technical approach.
NCC 2025
For projects governed by NCC 2025, J1V3 remains a reference-building Verification Method, but the technical benchmark is more demanding. The updated method introduces a defined performance margin, revised thermal-condition tests and changes to the modelling parameters used to establish the proposed and reference buildings.
The changes reinforce the distinction between whole-building performance and envelope performance. Efficient services and on-site renewable energy remain relevant to the overall result, but they do not remove the need to demonstrate that the proposed building fabric and façade perform appropriately against the reference-building benchmark.
NCC 2025 should only be used where it has been adopted for the project. The applicable jurisdiction, transition arrangements and code edition should be confirmed before the modelling basis is established.
Performance Margin
The proposed building’s annual greenhouse-gas emissions must be no more than 97% of the reference-building result when the proposed services are modelled. Matching the reference building is therefore no longer sufficient under this comparison.
Envelope Safeguard
The proposed building must also be assessed using the same services as the reference building. This preserves a distinct check on the building envelope and limits the ability to compensate for weak fabric performance through efficient services or renewable generation alone.
Thermal Conditions
Class 5 buildings may continue to use the prescribed Predicted Mean Vote test. NCC 2025 also provides dry-bulb room-temperature and climate-zone-based peak heating or cooling load methods as alternative ways to assess internal conditions.
Climate Inputs
Specification 34 introduces revised requirements for climatic data and air-conditioning parameters. The selected climate information therefore forms part of the defined compliance methodology rather than an interchangeable modeller preference.
Operating Profiles
NCC 2025 revises several modelling profiles used for building operation. Occupancy, lighting and air-conditioning assumptions should be checked against the updated specifications rather than carried forward automatically from an NCC 2022 model.
Renewable Energy
NCC 2025 introduces installed on-site solar photovoltaic systems for relevant commercial buildings and further specifies the reference-building methodology. Project teams should not assume that adding solar to the proposed building will create the same modelling advantage available under an earlier code edition.
| Assessment method | Principal criterion | Building or climate context | Coverage requirement |
|---|---|---|---|
| Predicted Mean Vote | PMV between -1 and +1. | Available for a Class 5 building. | At least 95% of occupied-zone floor area for at least 98% of annual operating hours. |
| Dry-bulb temperature | 18°C to 25°C for transitory occupancy and 21°C to 24°C for other conditioned spaces. | An alternative across the applicable Class 3 and Class 5 to 9 buildings. | At least 95% of occupied-zone floor area for at least 95% of annual operating hours. |
| Peak zone load comparison | The proposed zone’s 98th-percentile heating or cooling load is compared with the corresponding reference-building zone. | Cooling in climate zone 1, heating in climate zone 8, or both heating and cooling in climate zones 2 to 7. | Applied across 95% of the assessable floor area using the prescribed comparison limits. |
The changed comparison threshold, reference-building inputs, climatic data, operating profiles and thermal-condition criteria can alter both the modelling process and the design response. Existing models should be reviewed against the full NCC 2025 methodology before they are relied upon for a project governed by the newer edition.
The changes described here apply to the NCC 2025 J1V3 method for Class 3 and Class 5 to 9 buildings. The proposed NCC 2025 Section J changes for Class 2 buildings did not proceed, and their regulatory basis should be considered separately.
For a focused explanation of the revised 97% comparison, envelope safeguard, thermal-condition pathways, climate inputs and solar PV context, read NCC 2025 Changes to JV3 and J1V3 Modelling.
After the applicable edition and modelling method have been confirmed, the project information can be assembled and checked against the JV3 documentation requirements.
Project Information
A reliable JV3 model depends on coordinated information about the building geometry, envelope, glazing, operation and relevant building services. The required level of detail varies with the project stage, building classification, applicable NCC edition and Performance Solution scope.
Preliminary architectural drawings may be sufficient to establish the likely modelling scope. As the assessment progresses, the model should be updated using confirmed construction properties, glazing performance, zoning, operating schedules and services information.
The proposed-building model, report, drawings and specifications should ultimately describe the same design. Unresolved assumptions or inconsistencies can affect the validity of the performance comparison.
Geometry and Zoning
Floor and roof plans
Elevations and sections
Building orientation and site context
Conditioned areas, uses and thermal zones
Envelope and Façade
Wall, roof and floor build-ups
Insulation and thermal properties
Glazing and frame specifications
Shading devices and external obstructions
Operation and Use
Building classifications and space uses
Occupancy and operating schedules
Lighting and equipment loads
Special operational conditions, where relevant
Building Services
Air-conditioning and ventilation systems
Lighting systems and controls
Heated-water and other regulated services
Renewable-energy systems, where applicable
Project address and climate location
Applicable NCC edition
Building classifications
Performance Solution scope
Certifier or building surveyor comments
Jurisdictional variations, where relevant
Where information is not yet confirmed, assumptions should be identified clearly and reviewed as the design develops. Material changes to geometry, glazing, envelope construction, zoning, schedules or building services may require the model and associated documentation to be updated.
Project teams seeking a formal modelling scope or assessment can submit the available documents through the JV3 assessment service.
Modelling Process
JV3 modelling develops through a coordinated sequence of model construction, input verification, performance comparison and design review. The process is not limited to producing a final energy result; it must also establish that the proposed-building model accurately reflects the design being documented.
The exact sequence varies with the building, applicable NCC edition and Performance Solution scope. Some stages may repeat as glazing, envelope construction, zoning or building services are refined.
Stage 01
The project location, building classifications, applicable NCC edition, climate data and Performance Solution scope are established before the models are developed.
Stage 02
The architectural design is translated into model geometry, conditioned areas and thermal zones that reflect the building form, orientation, space uses and operating patterns.
Stage 03
The proposed model represents the project design, while the reference model is configured using the requirements and assumptions prescribed by the applicable Verification Method.
Stage 04
Envelope properties, glazing, shading, occupancy, schedules, internal loads and relevant building services are checked so the model remains consistent with the available project information.
Stage 05
The proposed-building result is assessed against the reference-building benchmark and any applicable envelope, comfort or other safeguards required by the Verification Method.
Stage 06
The modelling outcome, Performance Solution documentation, drawings and specifications are coordinated so the assessed design and the documented design remain consistent.
An initial model may identify where the proposed building does not yet satisfy the required comparison or an applicable safeguard. The project team can then review design variables such as glazing, shading, insulation, façade construction or services before the model is updated.
This does not mean that design elements can be traded without limitation. Each revision must remain consistent with the applicable modelling rules and the Performance Solution being developed.
Material changes made after modelling should be reviewed before approval or construction. Changes to geometry, zoning, glazing, envelope properties, operating assumptions or building services may alter the result and require the model and supporting documentation to be updated.
Model Development
The complexity of a JV3 model depends on how much of the building must be represented, how many distinct thermal and operational conditions are present and how complete the available design information is.
A compact building with consistent uses, straightforward geometry and coordinated documentation may require a relatively contained modelling scope. Mixed classifications, irregular forms, multiple façade systems, varied schedules and detailed services can require more extensive zoning, assumptions and design coordination.
Complexity does not determine whether a project will comply. It affects how the proposed and reference buildings must be represented and how carefully the model, assumptions and project documentation need to be aligned.
Building Form
Irregular floor plates, multiple orientations, atria, split levels and varied conditioned areas can increase the number of zones and surfaces that must be represented.
Façade Design
Multiple glazing systems, façade orientations, frame types, shading devices and external obstructions can require more detailed model inputs and checking.
Building Use
Mixed uses, different occupancy patterns, extended operating hours and specialised spaces may require distinct zoning, loads and operating assumptions.
Building Services
Different air-conditioning systems, ventilation strategies, lighting controls and other regulated services may need to be represented across separate parts of the building.
Project Information
Incomplete schedules, conflicting drawings or unconfirmed performance values create assumptions that must be resolved before the final model can reflect the documented design.
Design Development
Changes to glazing, shading, insulation, zoning or services may require model updates and renewed comparison against the reference-building outcome.
A technically complex building can still be modelled effectively when the architecture, façade, construction and services information is coordinated. Conversely, even a relatively simple building can become difficult to assess when key inputs remain unclear or inconsistent.
Project-specific modelling scope, delivery requirements and commercial details can be confirmed after the available documentation has been reviewed through the JV3 assessment service.
Common Misunderstandings
JV3 can be a useful performance solution pathway, but it is often misunderstood. It should not be treated as a shortcut, a guaranteed cost-saving method or a way to avoid compliance requirements.
The purpose of JV3 is to demonstrate energy performance through modelling. It can provide flexibility where a project does not neatly follow the DTS pathway, but the proposed building still needs to satisfy the required NCC energy performance outcome.
A clear understanding of what JV3 can and cannot do helps project teams avoid late-stage assumptions, unrealistic expectations and unnecessary redesign pressure.
Misunderstanding
JV3 is not separate from Section J. It is a performance solution pathway used within the broader NCC commercial energy efficiency compliance framework.
Misunderstanding
JV3 may provide a more suitable pathway for some projects, but it can also require more detailed modelling, documentation and coordination than a straightforward DTS assessment.
Misunderstanding
JV3 may help explore design options, but it should not be assumed to reduce cost. Cost outcomes depend on the design, modelling results, documentation and any required changes.
Misunderstanding
JV3 can assess glazing as part of the whole building performance model, but the proposed building still needs to demonstrate compliance through the modelling outcome.
Misunderstanding
JV3 is usually easier to manage when considered earlier. Late-stage modelling can create pressure if the assessment identifies missing information or design changes.
Misunderstanding
JV3 is often associated with larger or more complex commercial projects, but relevance depends on the building, design pathway and compliance requirements rather than size alone.
Treat JV3 as a technical compliance pathway, not a workaround. The best first step is to review the project documents, understand the design intent and confirm whether a performance solution is genuinely appropriate for the building.
Frequently Asked Questions
JV3 is the commonly used industry term for a reference-building Verification Method within the NCC commercial energy-efficiency framework. Under applicable NCC editions, the method is formally referenced as J1V3. It compares a proposed-building model with an NCC-defined reference building and may be used as evidence supporting a Performance Solution.
No. Section J is the broader NCC framework covering energy efficiency for relevant commercial and non-residential buildings. JV3 or J1V3 is a Verification Method that sits within that framework and provides a structured way to assess a proposed Performance Solution through comparative modelling.
The proposed-building model represents the project as designed, including its geometry, orientation, envelope, glazing, shading, zoning and relevant services. The reference building establishes the compliance benchmark using the characteristics and assumptions prescribed by the applicable Verification Method. The two models are assessed under corresponding conditions so their results can be compared meaningfully.
The modelling scope may include building form, thermal zoning, orientation, climate data, walls, roofs, floors, glazing, frames, shading, occupancy schedules, internal loads and relevant building services. The precise scope depends on the building classification, project design, applicable NCC edition and Performance Solution being developed.
No. Whole-building modelling can recognise interactions between the envelope, glazing and relevant services, but trade-offs are not unlimited. The proposed building must satisfy the required performance comparison together with any applicable envelope, thermal-comfort or other safeguards contained in the relevant Verification Method.
Assumptions about occupancy, operating hours, equipment loads, lighting, thermal zoning and building services can materially influence the modelled outcome. Assumptions should be clearly identified, technically supportable and replaced with confirmed project information as the design develops.
Typical information includes architectural plans, elevations and sections; building classifications and space uses; wall, roof and floor construction details; glazing and frame specifications; shading information; occupancy and operating schedules; and relevant mechanical, ventilation, lighting and heated-water system details.
The applicable NCC edition depends on the project location, approval timing, jurisdictional adoption arrangements and any relevant transitional provisions. It should be confirmed before modelling begins because the reference-building rules, weather data, performance criteria and safeguards can vary between editions.
Material changes to geometry, orientation, glazing, shading, envelope construction, zoning, operating assumptions or building services may alter the modelling result. The changes should be reviewed so the proposed-building model, Performance Solution report, drawings and specifications continue to describe the same design.
Not by itself. The proposed building must achieve the required comparison while also following the applicable modelling methodology and satisfying any additional criteria or safeguards required by the relevant NCC edition. The modelling result forms part of the broader Performance Solution evidence.
Related Knowledge
JV3 sits within a broader commercial energy-efficiency framework. These related resources explain the parent Section J requirements, compare the principal compliance pathways and explore façade considerations that can influence commercial building performance.
Parent Framework
Understand the commercial energy-efficiency framework, its scope, applicable NCC editions and the principal ways compliance may be demonstrated.
Pathway Comparison
Compare the prescribed Deemed-to-Satisfy pathway with JV3 reference-building modelling and understand the considerations that may influence pathway selection.
Façade Compliance
Explore how glazing, façade configuration and the NCC Façade Calculator relate to prescriptive Section J assessment and JV3 modelling.
Commercial Knowledge
Navigate the wider commercial ecosystem, including Section J, JV3, commercial DTS, NABERS, Green Star and other building-performance pathways.
JV3 Project Review
Send the available architectural drawings, glazing information, construction details and known building-services documentation for review.
Certified Energy can confirm the likely modelling scope, identify any additional project information required and provide project-specific guidance on progressing the JV3 assessment.
Preliminary documentation can be reviewed before every modelling input has been finalised.
Last reviewed: July 2026. This page is maintained by Certified Energy as part of its Commercial Performance Knowledge Hub.
