The National Building Code (CNC) 2022 will be available from October 1, 2022, with a series of new performance requirements designed to improve habitability and reduce energy consumption and carbon emissions. This update addresses the new NCC 2022 energy efficiency requirements.
The proposed changes to NCC 2022 to address energy waste are timely given that the residential construction sector in Australia accounts for 11% of total energy consumption, approximately 23% of electricity consumption and is responsible about 11% of national greenhouse gas emissions. Much of this energy consumption can be attributed to poorly designed homes and appliances that allow heat loss (leakage) during the winter months and cause power surges to run inefficient air conditioners during the winter months. of summer. The result of these inefficiencies is increasing carbon emissions and already increasing homeowners’ electricity bills as the power grid struggles to keep up with demand.
The NCC (2022) will impose a performance requirement on designers, developers and builders to design and build more energy-efficient homes. It aims to achieve this by imposing a performance requirement on houses and apartments to achieve the equivalent of ‘7 stars’ NatHERS thermal performance.
“NatHERS” is the National Home Energy Rating System, a software-based home energy rating system that facilitates consistent (out of 10 star) energy ratings from software tools that rate the energy efficiency of homes based on of their design. The “star” rating stickers we commonly see on refrigerators and other appliances will now apply to the entire residential home and will include heating and cooling systems, water heaters, lighting, pool pumps and spas, as well as solar panels and batteries. The higher the star rating, the more energy efficient the home will be, leading to emission reductions and savings on electricity bills. Specialized software packages used or accredited by NatHERS simulate the entire property using the geometry of the building envelope and neighboring buildings and also capture all 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 zone where the property is located. If the loads are too high, the building design can be modified (eg materials, insulation, orientation, etc.) to ensure compliance.
New South Wales has separate heating and cooling load limits (or “caps”) covered by its Building Sustainability Index (BASIX) Thermal comfort requirements. BASIX requirements are part of the development approval process for new residential accommodation under NSW Environmental Planning and Assessment (Development Certification and Fire Safety) Regulations 2021 (Cth) and can be obtained after submitting an online assessment and obtaining a BASIX certificate. The BASIX certificate must be submitted with a development request or a conforming development certificate. Changes to the BASIX standards in New South Wales will make these standards consistent and complementary with those of the proposed NCC (2022), i.e. there will be a BASIX requirement that an increase in the standard of thermal performance from an average of 5.5- 6 stars to 7 NatHERS stars.
The new energy requirements will only apply to houses and other low-rise multi-dwelling projects (Class 1 buildings) and apartment buildings (Class 2 single-occupancy units and parts of Class 4 buildings) . The NCC 2022 will be available from October 1, 2022 (for compliance on a voluntary basis), then will start on May 1, 2023 with a transition period until October 1, 2023 to allow all stakeholders and affected parties to s adapt before the requirements become mandatory.
The future home may look somewhat different from today, for example air conditioning units can potentially become redundant using building geometry, geography and sun angle. The NCC 2022 suite of documents presents an admirable approach to improving energy efficiency in homes and will hopefully lead to new design and construction initiatives at a critical time of energy supply constraints and global warming.