Whole-of-Home Energy Budget (NCC 2022 Section J)

What This Requirement Covers

The Whole-of-Home Energy Budget in NCC 2022 Section J sets minimum energy performance and fabric requirements for buildings to reduce energy consumption, lower peak demand, and cut greenhouse gas emissions while protecting occupant health and amenity. It covers thermal performance of the building envelope, energy efficiency of key services and equipment, and features to facilitate future distributed energy resources (DER) such as rooftop solar and electric vehicle charging. The provisions apply across a range of building classes and include both performance-based objectives (Part J1) and Deemed-to-Satisfy (DtS) elemental provisions (Parts J2-J9) that provide prescriptive pathways to compliance.

This requirement exists to ensure new buildings perform to an agreed national standard for energy efficiency while being adaptable for low-emission technology retrofits. It applies to buildings regulated by the National Construction Code (NCC) 2022 (Volume One and Volume Two as applicable), including single dwellings and multi-unit residential buildings where Section J is invoked, and non-residential buildings covered by Volume One. State and territory schedules may modify the national provisions in some jurisdictions.

Key Requirements

1. Objective and performance scope: The performance objectives are set out in NCC 2022 Volume One, Part J1 (Objective J1O1 and Performance Requirements J1P1-J1P4). The building must reduce energy consumption and peak demand, reduce greenhouse gas emissions, protect occupant health and amenity, and be able to accommodate future DER installations (NCC 2022 Volume One, J1O1; J1F1).
2. Deemed-to-Satisfy pathway: Compliance may be achieved by meeting the DtS provisions in Parts J2-J9 as referenced in J3D1/J4D1. For sole-occupancy units of Class 2 and Class 4 parts, DtS provisions for thermal insulation, glazing, and services are contained in J3 and J4 (NCC 2022 Volume One, J3D1; J4D1).
3. Building fabric thermal performance: DtS fabric provisions specify minimum insulation and glazing performance by climate zone and construction type in Part J4. Specific thermal resistance (R-values) and insulation thicknesses are given in tables in Part J4 (see NCC 2022 Volume One, Part J4D2-J4D7). These are expressed in terms of required insulation R-values or equivalent thicknesses for roofs, walls, and floors (refer to J4 tables for precise numeric values by climate zone).
4. Glazing and shading: DtS glazing provisions set maximum glazing area ratios and required glazing properties (U-values, solar heat gain coefficients) for different orientations and climate zones in Part J4. Where shading devices are required, dimensions and performance are set out in J4 tables and guidance (NCC 2022 Volume One, Part J4).
5. Domestic services and equipment efficiency: Part J3 contains DtS requirements for the energy efficiency of domestic hot water systems, space heating and cooling equipment, lighting, and associated controls for sole-occupancy units (NCC 2022 Volume One, J3D2-J3D15). It includes minimum efficiency metrics for equipment and requirements for timers, thermostats, and temperature setpoints where relevant.
6. Provision for DER and future retrofit: Part J9 requires features to facilitate retrofit and monitoring - including space and infrastructure for easy installation of photovoltaic systems and EV charging, and energy monitoring capability (NCC 2022 Volume One, J9D1 and Part J9 DtS provisions). Exact DtS measures include conduit or reserved space dimensions, metering access and layout to facilitate future wiring and connection (see J9D clauses).
7. Specific code references: Key references include NCC 2022 Volume One, Part J1 (Objectives and Performance Requirements J1O1, J1F1), Part J2 (application and DtS framework J2D1), Part J3 (domestic services J3D1-J3D15), Part J4 (building envelope J4D1-J4D7), and Part J9 (DER facilitation J9D1). Where DtS solutions are used, comply with the relevant tables and clauses listed in those parts.
8. Relevant Australian Standards and cross references: Where construction methods or materials are specified, compliance should be in accordance with applicable Australian Standards such as AS 1684 (timber-framed construction), AS 4100 (steel structures) and AS 3700 (masonry) as required by the building design and referenced DtS provisions. Specific equipment efficiency standards and test methods referenced by Section J clauses should be followed as cited in the NCC and relevant schedules.

Residential vs Commercial

1. Residential (Class 1 and Class 10 where applicable; and sole-occupancy units in Class 2 / Class 4 parts): Section J places a strong focus on occupant amenity, thermal comfort, and independent domestic services. DtS provisions in Parts J3 and J4 are largely written for sole-occupancy units and set explicit insulation R-values, glazing limits, and domestic service efficiency requirements. For Class 2 sole-occupancy units and Class 4 parts, the DtS pathway in J3/J4 is the primary route cited (NCC 2022 Volume One, J3D1; J4D1).
2. Commercial and other classes (Class 3 and Classes 5-9): Section J applies with different emphasis toward energy use of central building services, plant, and system-level efficiency. DtS provisions in Parts J4 and J9 apply to the envelope and DER facilitation, but many performance requirements for Class 5-9 buildings are system-level and may require performance solutions rather than the residential DtS tables. Part J9’s requirements for monitoring and DER readiness are particularly relevant for larger commercial buildings where centralised plant, metering, and future load management are critical.

Exceptions and Exemptions

1. State-specific substitutions: Some jurisdictions have transitional or substitute provisions for particular building types (for example, Tasmania uses Section J from BCA 2019 Amendment 1 for Class 2 and Class 4 parts) - these are noted in the NCC and must be checked where applicable (NCC 2022 Volume One notes for Part J).
2. BASIX and NSW variations: For Class 2 and Class 4 where BASIX certificates (NSW) apply, the applicable version of BASIX or whether the development consent expressly requires an earlier Section J may determine whether the NCC 2022 Section J or earlier Section J versions apply. This is specifically noted in the NSW clauses of Parts J2-J4 (NCC 2022 Volume One, J2 and J3 notes).
3. Performance solutions: Where DtS provisions cannot be met, a performance solution may be adopted under the NCC’s Performance Requirements (Part J1). The performance solution must demonstrate equivalent or superior outcomes against J1P1-J1P4 and cite relevant tests, modelling or evidence.

State and Territory Variations

1. New South Wales: NSW has specific transition references - for certain Class 2 and Class 4 scenarios compliance may be determined by BASIX certificate version and state notes in Parts J2-J4. From 1 October 2023 Section J of NCC 2022 generally applies, but NSW transitional references in J2-J4 must be checked (NCC 2022 Volume One notes J2/J3/J4).
2. Tasmania: Section J for Class 2 and Class 4 parts is replaced by Section J of BCA 2019 Amendment 1 for those building classes; confirm local requirements (NCC 2022 Volume One, Part J notes).
3. Other jurisdictions: The NCC contains schedules (Schedules 4-12 in Volume One) and state notes that may modify or add provisions for Section J. Always check the relevant state or territory schedule in NCC 2022 Volume One for amendments that may alter insulation requirements, glazing rules, or DER facilitation measures.

Practical Compliance Tips

1. Check the correct version and state schedule first - Confirm whether NCC 2022 Section J or an earlier Section J variant or state schedule applies to the project, particularly for Class 2 and Class 4 in NSW and Tasmania (NCC 2022 Volume One, relevant notes).
2. Use the DtS tables for your climate zone - When following the Deemed-to-Satisfy route, pick the correct climate zone tables in Part J4 for roof, wall and floor R-values and glazing limits; mismatching climate zones is a common error.
3. Document performance solutions thoroughly - If adopting a performance solution, provide energy modelling or test data demonstrating equivalence to J1P1-J1P4 and cite the specific NCC clauses used in the justification.
4. Plan for DER early - Reserve conduit space, metering access and roof area for PV and EV infrastructure in line with Part J9 DtS guidance so retrofit is simple and cost-effective.
5. Coordinate services and controls - Ensure hot water, heating/cooling, lighting and controls meet J3 DtS provisions; inefficient controls or incorrectly sized plant are frequent non-compliances.
6. Follow referenced Australian Standards - Where Section J refers to construction standards, confirm compliance with the appropriate standard (for example, AS 1684, AS 4100, AS 3700) to avoid conflicts between structural and thermal requirements.
7. Engage certifiers early - Involve the building certifier or energy specialist during design to verify chosen DtS tables or the adequacy of a proposed performance solution against NCC 2022 Volume One Part J1 clauses.

Sources: NCC 2022 Volume One - Building Code of Australia, Part J (J1, J2, J3, J4, J9) and related notes and DtS provisions. (Referenced clauses and tables are within NCC 2022 Volume One, Part J.)