NCC 2019 upcoming changes – Energy Efficiency / Section J Compliance

2 May 2019

NCC 2019 is here. Are you prepared for the biggest overhaul of the decade under the Energy Efficiency provision? Find out what it means for your current and upcoming projects.


Why the change?

To align with the COAG National Energy Productivity Plan, the revised Section J provision aims to reduce greenhouse gas emission and improve energy productivity by 40% by 2030.

Changes period

The official NCC 2019 came into effect from 1st of May 2019. However, the Section J Energy Efficiency provision is given an additional 12-months transition period until the enforced date. This means for any project with a Construction Certificate submission date that is before 1st of May 2020, the current Section J requirements (NCC 2016 Amdt 1) can be still applied.

What are the changes

  • Residential buildings (class 1, 2 and 4) – Introduced NatHERS heating and cooling load limits (on top of existing minimum star rating) for Class 1 building. For NSW, BASIX compliance requirements remain relatively unchanged
  • Commercial buildings (class 2 common area, 3, 5, 6, 7, 8 & 9) – Increased compliance provision requirements and added new verification methodologies, primarily included:
    • Changed energy consumption to greenhouse gas emissions – Increase weighting on renewable energy sources, i.e. Solar PV and onsite heat reclaimed systems
    • Introduced NABERS and Green Star verification pathway – Prequalification for Green Star & NABERS projects
    • Introduced Building Envelope Sealing verification pathway – Require blow test
    • Implemented occupancy comfort assessment clause – Required thermal comfort modelling to assess PMV level
NCC Section J Parts2016 DTS compliant2019 DTS compliant (NCC19 Preview)Potential Impacts
J1-FabricFollow prescriptive R-value requirement for all fabric elementso  Non-Façade element – Follow prescriptive R-value requirement for roof, ceiling, roof light and flooro  Façade element – new calculation methodology to determine wall & glazing performance requiremento Thicker building fabric insulationo Insulation required for all floor types

o Higher performance glazing system

o Offer glazing performance offset opportunities without JV3 pathway.

o Greater benefits for low glazing ratio building design OR building which has concentrated glazing on a fixed orientation but opaque element for the other facades

J2-Glazing (Removed)Independent from wall thermal performance requirement, follow ABCB prescribed glazing calculator to determine glazing performance requirementNew manual calculation to assess wall & glazing requirements as a combined façade element.o Longer turnover time to determine compliance requiremento Early commitment to wall construction type

o The same building façade requires better glazing system or reduction in glazing ratio, compared to NCC16**


J3-Building SealingPrescriptive sealing requirementNo fundamental changeN/A
J5-Air-conditioning & ventilation systemsPrescriptive requirements to select mechanical systems based on the minimum targetsImproved prescriptive requirements:o Increased Control – VSD, temperature band, comfort, damper & time switch

o Improved outside air treatment

o Increased Fan efficiency

o Added EU regulations requirement for Pump system

o Increased insulation

o Increased heating thermal efficiency

o Increased chiller/unitary system efficiency

o Improved heat rejection fan equipment power

o Stricter requirements for system control/fan/pump/insulation/efficiencyo Possible new calculator for mechanical systems





J6-Artificial lighting & powerPrescriptive requirements to select lighting systems based on the minimum targetso Added criteria for light quality – CRI & CCTo Significant reduction of max lighting power density

o Revised control device adjustment

o Added criteria for carpark lighting & control

o Added criteria for lift energy, escalator & moving walkway control

o Less impact to JV3 thermal loado Commitment to LED lighting products

o Greater lighting control coverage


J7-Heated water supply and swimming pool and spa pool plantPrescriptive requirements to select heated water systems based on the minimum targetsNo fundamental change, increased system efficiency, insulation and controlN/A
J8-Facilities for energy monitoringPrescriptive requirements to select energy monitoring systemNo fundamental change, added needs for time-of-use data capturing capabilityN/A


**The following case study outlines the potential impacts on glazing performance requirement by switching from NCC 2016 glazing calculator to NCC 2019 wall-glazing calculation methodology.   

This hypothetical study theorised a single storey building, consisting of facades on every orientation sector as defined in part J2.4, NCC 2016. The glazing ratio is assumed constant for all façade and shaded by 1.5m width awning at 3.1m height. By varying the glazing ratio, the averaged U-value and SHGC-value are determined and compared under the NCC 2016 and NCC 2019 protocols.

Figure 1: Plan view of the case study building
Figure 2: Minimum averaged U-values required (NCC 16 vs NCC 19)
Figure 3: Minimum averaged SHGC-values required (NCC 16 vs NCC 19)


The above charts demonstrate the impact of the NCC 19 Section J provision on glazing performance. For Facades with higher glazing ratio, lower U-value systems are required. I.e. 40% glazing ratio requires double glazing systems, whereas single float systems would be sufficed under NCC 16 provision. The subsequent impact of the NCC19 change means additional implication to the cost and space allowance to the project.

BCA Energy can provide solutions that can minimise the cost effect of changing to the new NCC 19 wall and glazing calculations. We will work with the builder or architect to optimise the glazing design to provide a well-designed and cost efficient building or alteration.

How can I prepare myself for the change?

Don’t want to get caught out by the new changes? Contact us at to organise an NCC 19 Section J update presentation, or feel free to give us a call to discuss the impacts for your project 1300 787 302. Our multidisciplinary teams also offers NCC 19 update sessions on Building Regulation + Access and Fire Safety requirements.