Building energy efficiency in new homes
It is important to meet emissions reduction targets using a range of methods. Building more energy efficient new homes can help us decarbonise and has added heath and economic benefits, such as improved mental health and lower household bills for residents, and better electricity grid performance.
Volume builders are companies that use a fixed range of building designs to build hundreds or thousands of new homes each year. We wanted to know how this important component of the Australian housing market is responding to higher energy efficiency requirements.
Is there room for improvement?
New houses in Australia have mandatory minimum requirements for energy efficiency, which builders can meet using different methods, such as adding insulation or solar PV systems, or adjusting the way a house is oriented on a block, or the types and sizes of windows.
CSIRO social scientists asked volume builders about increasing energy efficiency requirements in new homes, consumer demand and the effects on their businesses. We wanted to know about their experiences and what they thought were trade-offs in building more energy efficient houses.
A ceiling on energy efficiency requirements
Mandatory minimum requirements have been important to lift standards for new homes and meet emissions reduction targets.
But, if we want to go beyond minimum requirements, we will need better 'thermal performance' – reducing the amount of heating or cooling needed to make a house comfortable. This means more investment to increase insulation levels or improve the thermal performance of windows.
The builders we interviewed expressed concern that such changes in their design packages are likely to affect their construction practices and supply chains, leading to higher material and construction costs. They were also concerned that products will not be available through their supply chains and their customers would not be willing to pay for energy efficiency beyond minimum requirements.
A program in Victoria is offering financial rebates and providing training to individuals and businesses to increase capability and capacity for delivering energy-efficient homes, but the interview findings suggest that these types of incentives are still rare.
Explore the Nationwide House Energy Rating Scheme (NatHERS), which measures energy efficiency for a building and produces a performance-based star rating.