Victorian Healthy Homes energy efficiency advice

The Victorian Healthy Homes program was a ground-breaking study seeking to understand how energy efficiency upgrades affect the health, comfort and financial situation of people receiving home and care services in Victoria.

For this, 1,000 households across Melbourne's western suburbs and the Goulburn Valley were offered free energy efficiency upgrades via the Victorian Government's Home Energy Assist package. The program was evaluated as a randomised controlled trial conducted over three consecutive winters.

As the program's energy research partner, ISF was responsible for measuring changes in residential energy efficiency, energy use, and thermal comfort associated with improved home energy efficiency and warmth. Additionally, we undertook statistical modelling to determine whether there is a significant difference in thermal comfort and indoor air quality in homes that received an energy efficiency upgrade.

ISF worked in partnership with colleagues at the UTS Centre for Health Economics Research and Evaluation (CHERE), who acted as the Victorian Healthy Homes program research partner. They designed and analysed occupant surveys for the project and assessed occupants' health outcomes with an emphasis on cardiac and respiratory illnesses, and evaluated the economic co-benefits.

Study findings indicated that a relatively minor upgrade (average cost $2,809) had wide-ranging benefits over the winter period. Indoor temperature increased by an average of 0.33 °C, reducing average exposure to cold conditions (below 18 °C) by 43 minutes per day. Poor quality dwellings (RES star rating below 5) saw nearly twice the increase in temperature (0.75 °C vs. 0.40 °C) compared to more efficient dwellings.

Subjective, self-reported experience of warmth was also measured, as it does not always match the temperature measurements. Householders in the intervention group were more than twice as likely as controls to report that their home felt warmer over winter. These gains in thermal comfort were obtained despite a significant reduction in gas use in upgraded homes, and no change in electricity use. Householders in the intervention group reported less condensation over winter as well.

Just as importantly, the upgrade was associated with benefits in health, with reduced breathlessness and improved quality of life, particularly its mental health and social care aspects. Health benefits of the upgrade were reflected in cost savings, with $887 per person saved in the healthcare system over the winter period. Cost-benefit analysis indicated that the upgrade would be cost saving within 3 years – and would yield a net saving of $4,783 over 10 years – due to savings in both energy and health. Savings were heavily weighted towards healthcare: for every $1 saved in energy, more than $10 is saved in health.