The NatHERS new Whole of Home rating is a significant advancement, encompassing the entire home’s energy use, including appliances, solar power, and battery storage. This update is the most substantial since the Scheme’s inception 30 years ago, aiming to enhance energy efficiency in new Australian homes. By supporting the design and construction of energy-efficient homes, this initiative aligns with Australia’s goal of achieving net zero emissions by 2050.

The Whole of Home rating facilitates compliance with the new energy efficiency standards set forth in the National Construction Code (NCC) 2022, recently introduced by Building Ministers. Key updates include a minimum 7-star standard and the introduction of an annual energy use budget.

NatHERS Whole of Home ratings offer a straightforward metric to demonstrate how a home meets or exceeds the NCC’s annual energy use budget. This requires evaluating the efficiency of appliances in new homes, alongside solar and battery integration. This new rating complements the existing NatHERS star rating (out of ten) by introducing a separate performance rating out of 100.

The expanded assessment builds on the thermal performance evaluation, providing insights into the energy usage of various household components:

• Heating and cooling systems
• Hot water systems
• Lighting
• Pool and spa pumps
• Cooking and plug-in appliances
• On-site energy generation and storage

The Whole of Home rating accounts for the energy consumed by these appliances, subtracting the energy generated by solar panels, to offer a comprehensive snapshot of both energy costs and greenhouse gas emissions.

With a scale ranging from 0 to 100—where 100 indicates a net zero energy home—the rating system allows for scores above 100. Homes achieving over 100 generate more energy than they consume, reflecting their superior energy efficiency.

This innovative rating system provides energy consultants with a valuable tool to promote and verify the energy efficiency of new homes, supporting Australia’s broader environmental and economic goals.