Victorian homes to help power our energy transition
Energy use in Victorian homes is responsible for generating more than one fifth of Victoria’s net carbon emissions. To reach net zero emissions by 2045, it is critical that Victorian homes become more energy-efficient and use renewable electricity.
SV’s multi-year research, the State of Sustainability Report 2023, reveals the sustainability mindset of the Victorian community including how Victorian homes are powered and how well they maintain comfortable and healthy temperatures.
Ian McNicol, Sustainability Victoria’s Senior Energy Efficiency Advisor says that a home’s carbon emissions from energy use depends on 3 things: thermal quality, selection of energy-efficient appliances, and the energy source used to power the appliances.
Improved thermal quality for better health
According to the World Health Organisation, a healthy and comfortable indoor temperature sits between 18 and 24 degrees Celsius. The inside temperature in older, inefficient houses that have no or inadequate heating can be below 18 degrees Celsius for more than half of the year, and on hot days can quickly rise above 24 degrees Celsius.
The research highlights the pressing need to lift the thermal performance of Victorian homes, with 39% classified as having poor to extremely poor thermal quality. This means the roof, walls, floors, windows, and external doors, are inadequately insulated and sealed to maintain a stable and comfortable inside temperature.
Between 13% and 18% of those surveyed said they didn’t know what insulation lies beyond their ceiling and walls, indicating that figure could be much higher than 39%.
Given the strong correlation between poor insulation and temperature control, it is unsurprising that many Victorians are feeling uncomfortable in their homes, with 44% indicating their homes were a lot hotter than they would like and 39% a lot colder.
Extreme highs and lows in temperature pose dangerous risks to the occupant’s health, exacerbating cardiovascular, respiratory, and mental health conditions.
Toby Cumming, Sustainability Victoria’s Team Leader of Evaluation and Research who led the organisation’s Healthy Homes program says, “'With Victoria's cold winters and hot summers, it is essential for householders to understand the health risks”.
The Healthy Homes program demonstrated that relatively minor energy efficiency upgrades costing an average of $2,800 per home could improve thermal comfort over winter months and reduce healthcare costs by $887 per householder.
Increased standards for better performance
Houses built prior to 1991 (that haven’t been retrofitted or renovated) are the least efficient in Victoria. Having an average estimated Nationwide House Energy Rating Scheme (NatHERS) rating of only 1.6 stars out of a possible 10, these houses are much more difficult and expensive to heat and cool than comparable homes built to today's energy efficiency standards.
Given more than 50% of Victorian homes were built pre-1991 before energy efficiency standards came into play, there is great opportunity to improve the efficiency and thermal quality of these homes. Since 2005, minimum efficiency standards have required all new houses to be much more efficient, starting at a 5-Star NatHERS rating, increasing to 6 Stars in 2011 and rising to 7 stars from 1 May 2024.
Homes built today are much better insulated and airtight, resulting in greater comfort for the occupants and lower heating and cooling costs.
The State of Sustainability data indicates Victorians clearly understand the link between energy-efficiency and cost savings. Most Victorians who are renovating or building agree that higher energy-efficient homes will result in lower energy bills (80%). Seventy-two per cent also acknowledge that higher upfront costs for a more sustainable, energy-efficient home would be recovered in the long run.
The road to electrification
Victoria’s historical reliance on gas to power their homes — previously the cheapest option — is reflected in the research, with 88% of homes still using at least one gas appliance.
Despite the current gas use, Victorians believe that moving away from fossil fuels is important. The research reveals that almost all Victorians (96%) would consider switching at least one appliance from gas to electric, and when asked if they would consider going “all-electric", 52% said yes.
According to the survey data, only 3% of Victorian homes have energy-efficient all-electric appliances, including a reverse-cycle air conditioner, a heat pump water heater and induction cooking.
“Creating a truly energy-efficient, low-emissions home is impossible without electrification,” explains Ian. “Transitioning our homes from gas to energy-efficient all-electric appliances, powered by our increasingly renewable electricity supply, is essential if we are to reach our emissions targets.”
From January 2024, Victorian Government policy requires new homes that require a planning permit to be all-electric. The Victorian Energy Upgrades (VEU) program also supports households and business to upgrade to energy-efficient electrical appliances and equipment. Rebates for solar panels and heat pump water heaters are available through Solar Victoria.
“An added benefit is that the annual energy bills of all-electric homes are lower than the annual energy bills of mixed-fuel homes that use gas for heating, water heating and cooking, and this difference is likely to increase over the decade,” Ian said.
Find out more
Read the full report to see how Victorians feel about climate change, energy efficiency, circular economy, sustainable behaviours, and the role of local and state government.
The research is delivered as part of Sustainability Victoria’s social research program, which builds an evidence base for future investment in sustainability in our state.