Achieving a 7-star energy efficiency rating for buildings in Victoria, Australia, represents a significant milestone in the journey toward more energy-efficient new homes, renovation or extensions. This rating, which surpasses the previous 6-star standard, is attainable through a series of strategic and well-considered design and construction choices. These choices not only contribute to a building’s environmental sustainability but also offer long-term financial savings for homeowners by reducing energy consumption.
Building Design and Orientation
One of the key strategies for reaching the 7-star rating involves optimizing the design and orientation of the home to harness the sun’s natural warmth during winter months while minimizing heat penetration during the summer. This passive heating and cooling approach is both cost-effective and efficient, requiring minimal mechanical intervention to maintain comfortable indoor temperatures year-round.
Insulation
In addition to design and orientation, enhancing a building’s insulation is crucial. By improving ceiling, wall, and under-floor insulation, a home can significantly reduce heat loss in winter and heat gain in summer. This creates a more stable indoor environment, reducing the need for artificial heating and cooling and, consequently, lowering energy consumption.
Windows
High-performance glazing on windows is another essential factor in achieving the 7-star standard. This type of glazing offers superior insulation properties, helping to maintain consistent indoor temperatures regardless of external weather conditions. It acts as a barrier against heat loss in winter and heat gain in summer, further contributing to the energy efficiency of the home.
As the new standards are rolled out, volume builders may need to adapt their standard designs to meet the 7-star criteria. This could involve architectural modifications such as relocating the garage or alfresco areas to optimize sun exposure and shading. These changes, while potentially requiring initial adjustment, pave the way for the widespread adoption of more energy-efficient home designs in Victoria.
Reducing Energy Consumption
The introduction of the Whole-of-Home annual energy use budget represents another significant step forward in promoting energy-efficient homes. This approach focuses on reducing energy consumption across three major areas: hot water, heating and cooling, and lighting, which together account for 70-80% of a typical home’s energy use. By setting a tailored energy budget for new homes, the standards encourage the installation of efficient fixed appliances and the use of renewable energy sources to meet or offset energy consumption.
Homebuilders are afforded flexibility in how they meet the Whole-of-Home energy budget. This can be achieved through a combination of selecting high-efficiency appliances and incorporating renewable energy solutions such as rooftop solar panels. The choice of fuel type, whether gas or electricity, and the specific technologies employed, are left to the discretion of the builders and homeowners, as long as the overall energy budget is met.
The National Construction Code (NCC) 2022 has introduced varying levels of stringency for houses and apartments, acknowledging the unique challenges faced in improving energy efficiency in different types of dwellings. Particularly, apartments may have limited opportunities for on-site renewable energy generation and other efficiency enhancements. Therefore, the NCC has been designed to be flexible, accommodating the diverse ways buildings can achieve energy efficiency.
Furthermore, Nationwide House Energy Rating Scheme (NatHERS) will expand to include the Whole-of-Home energy budget alongside its traditional thermal performance rating. This expansion signifies a comprehensive approach to assessing and improving the energy efficiency of homes, taking into account both the thermal performance and the overall energy consumption of the dwelling.
The future of residential construction in Australia
Achieving a 7-star energy efficiency rating in Victoria requires a holistic approach that encompasses thoughtful design, advanced insulation, high-performance glazing, and a commitment to reducing energy consumption through efficient appliances and renewable energy sources. This standard not only reflects Victoria’s commitment to sustainable building practices but also sets a benchmark for the future of residential construction in Australia. By adhering to these guidelines, builders and homeowners can contribute to a more sustainable and energy-efficient future, enjoying the benefits of reduced energy costs.