Applying NCC 2019 Energy Efficiency

As of 1 May 2021, Western Australia has adopted NCC 2019 Amendment 1 and with it brings changes to the NCC energy efficiency provisions.

This information has been prepared to assist builders, assessors and practitioners appropriately demonstrate compliance with the Performance Requirements of the NCC and their application per the Building Act 2011 and the Building Regulations 2012 as required by the Department of Mines, Industry, Regulation and Safety (DMIRS), Building and Energy.

What’s the change?

NCC 2019 Amendment 1 has clarified that the use of NatHERS-based software (First Rate 5,Accurate, BERs Pro and HERO) is not permitted to be used as part of demonstrate compliance with the Verification Using a Reference Building Method (often referred to as ‘VURB’) V2.6.2.2.

Another change that was incorporated in the national NCC 2019 provisions was for additional assessment of separate heating and cooling load limits under a star rating assessment. However, that change has been dis-applied in WA meaning that the separate heating and cooling load limit caps assessment are not required as part of a star rating assessment in demonstrating compliance with the NCC energy efficiency provisions in WA. For further information on this change refer to Industry Bulletin 128.

However, it is important to note that all other provisions remain in force and must be demonstrated as part of a star rating assessment and this also includes meeting the additional Deemed-to-Satisfy Provisions in the NCC for:

• 3.12.1.1, for building fabric thermal insulation;
• 3.12.1.2(c) and 3.12.1.4(d), for thermal breaks;
• 3.12.1.5(c) and 3.12.1.5(d), for floor edge insulation; and
• 3.12.3 for building sealing.
• 3.12.5 for building services

It’s important to remember that a ‘6 star’ home can only be delivered through a NatHERS assessment pathway with accredited software. NCC 2019 also included changes to the building sealing provisions of Part 3.12.3 including more prescriptive details on applying the building sealing provisions and types of sealing required.

Building fabric assessment separately to building services 

The VURB pathway for demonstrating Energy Efficiency compliance is a Performance Solution, and one way to meet Performance Requirement P2.6.1. However, the VURB pathway does not demonstrate compliance with Performance Requirement P2.6.2 (building services), which covers energy efficient domestic services and fixed appliances requirements.

Additionally, NatHERS only demonstrates compliance with P2.6.1.

What’s the issue?

Building and Energy have been made aware that some assessors and practitioners are seeking to ‘trade-off’ or ‘offset’ the energy-generating ability of a solar panel / photovoltaic array (P2.6.2) with shortfalls of a building’s general thermal efficiency requirements (P2.6.1).

Performance Requirement P2.6.1 only prescribes outcomes to limit the use of energy for artificial heating and cooling of a building. It does not take into account the use of, provision for or generation of energy by any domestic service or fixed appliance.

As such, it is deemed inappropriate by Building and Energy to apply a renewable energy source as a consideration for meeting Performance Requirement P2.6.1.

Where can I find more information?

The ABCB Energy Efficiency NCC Volume Two 2019 Handbook is a detailed resource regarding the VURB pathway and Building and Energy have released Industry Bulletin 140 providing further information on the NCC energy efficiency provisions.