The 2022 NCC – Mandating energy efficient homes

The National Construction Code (NCC) 2022 will be available from 1 October 2022, with a raft of new performance requirements designed to improve liveability and reduce energy consumption and carbon emissions. This update focuses on the new energy efficiency requirements in the NCC 2022.

The proposed changes to NCC 2022 to address energy wastage are timely given the residential building sector in Australia accounts for 11% of total energy consumption, around 23% of electricity consumption and is responsible for around 11% of national greenhouse gas emissions. Much of this energy consumption can be attributed to poorly designed homes and appliances that enable heat to be lost (leaked) in the winter months and cause increases in power to run inefficient airconditioners in the summer months. The result of these inefficiencies increases carbon emissions and adds to homeowner’s already sky rocketing power bills as the energy grid struggles to cope with demand.

The NCC (2022) will make it a performance requirement for designers, developers and builders to design and construct more energy-efficient homes. It aims to achieve this goal by making it a performance requirement for houses and apartments to achieve the equivalent of ‘7 stars’ NatHERS thermal performance.

“NatHERS” is the Nationwide House Energy Rating Scheme, a house energy rating software scheme that facilitates consistent energy ratings (out of 10 stars) from software tools that assess the energy efficiency of dwellings based on their design. The ‘star’ rating stickers that we commonly see on fridges and other household appliances will now apply to the whole residential home and will include heating and cooling systems, hot water heaters, lighting, pool pumps and spas, and solar panels and batteries. The higher the star rating, the more energy efficient the home will be, leading to emissions reductions and savings on power bills. The speciality software packages used or accredited by NatHERS simulate the entire property using the geometry of the building envelope and neighbouring buildings and also input all the building construction parameters such as types and measurement of building materials. The predicted heating and cooling loads can then be determined and measured against an index based on the climate area zone where the property is located. If the loads are too high then the design of the building can be modified (for example materials, insulation, orientation etc.) to ensure compliance.

New South Wales has separate heating and cooling load limits (or ‘caps’) covered in its Building Sustainability Index (BASIX) Thermal Comfort requirements. The BASIX requirements are part of the development approval process for new residential dwellings under the NSW Environmental Planning and Assessment (Development Certification and Fire Safety) Regulation 2021 (Cth) and can be achieved after submitting an on-line assessment and obtaining a BASIX certificate. The BASIX certificate is required to be submitted with a development application or complying development certificate. Changes to the BASIX standards in NSW will make those standards consistent with, and complementary to, those in the proposed NCC (2022), that is, there will be a BASIX requirement that an increase of the thermal performance standard from an average of 5.5-6 stars to a 7 star NatHERS rating.

The new energy requirements will only apply to houses and other low rise multiple dwelling projects (Class 1 buildings) and apartment buildings (Class 2 sole-occupancy units and Class 4 parts of buildings). The NCC 2022 will be available from 1 October 2022 (for compliance on a voluntary basis), and will then commence on 1 May 2023 with a transitional period to 1 October 2023 to allow all stakeholders and affected parties to adjust before the requirements become mandatory.

The future home may look somewhat different to today, for example airconditioning units may potentially become redundant by utilising building geometry, the geography and the angle of the sun. The NCC 2022 suite of documents presents an admirable approach to improving energy efficiency in homes and will hopefully lead to new initiatives in design and construction at a critical time of energy supply constraints and global warming.

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Authored by:

Matthew Taylor, Partner
Shanna Kruger, Partner