Public housing tenants would be $1000 a year better off, more comfortable and healthier in low-carbon housing, according to a new study out of RMIT’s Centre for Urban Research, though narrow cost-benefit analyses could stop these houses from taking off.
The three-year study funded by the Victorian Department of Health and Human Services involved the construction of four super sustainable two-bedroom “Catalyst” houses in Horsham, Victoria.
The houses incorporated a number of ESD elements to get to an 8.9-star NatHERS rating, including:
- passive solar design
- optimum orientation
- advanced roof design
- improved levels of ceiling, wall and floor insulation
- external window shading
- access to natural ventilation
- increased thermal mass
- reverse brick veneer construction on back section of dwellings
- improved glazing
They also had access to shared 5000-litre rainwater tanks, individual 1.5kW solar PV systems and gas-boosted solar hot water heating. The apartments were built without airconditioning, though ceiling fans and gas heating were included.
Seven houses built to the standard six star NatHERS were used as controls in the study.
The Catalyst houses provided a range of benefits including:
- 62 per cent less electricity than department standards and 45 per cent less than controls
- three per cent less gas compared to the department standards and 15 per cent less gas compared to control households
- 28 per cent less water compared to the department standards and 22 per cent less water compared to control households
- 50 per cent less CO2 than department standards, and 40 per cent less CO2 than controls
- being substantially more comfortable during heatwaves
- $15,000-$40,000 additional resale value
Cost-benefit analysis holding back low-carbon housing
The study used both a typical cost-benefit analysis as well as a “non-traditional” lifecycle approach that factored in elements like running costs as well as health and comfort outcomes.
“This is a significant viewpoint in the context of public housing provision, when dwellings are commonly built, owned and managed by the department and house vulnerable people,” a Victorian Department of Health and Human Services statement said.
Using the standard cost-benefit analysis, the report found the Catalyst homes were not financially viable for DHHS.
The ESD elements of the Catalyst homes meant they cost an additional $75,700 per dwelling, and when maintenance and technology replacement costs across a 40-year period were included, it resulted in an extra $141,700 per dwelling.
However there were a number of factors that a typical cost-benefit analysis didn’t show. Household interviews found benefits such as:
- lower utility consumption and bills than in previous dwellings
- the ability to pay bills more easily with reduced stress
- savings available to spend on things that improved tenant quality of life and things that tenants previously struggled to afford, such as going on a holiday or buying clothes
- an improvement in thermal comfort and health during extreme weather (without requiring air conditioning), translating to fewer reported trips to the doctor or hospital
- overall improvement in life circumstances, life satisfaction and wellbeing, including one household removing themselves from all Centrelink payments
- improved neighbourhood satisfaction, perceptions of neighbourhood safety and relationships with the department regional office
According to lead author Dr Trivess Moore, a typical cost-benefit analysis ignores wider benefits to public housing tenants, providers and the wider community.
“Our study clearly shows that the housing sector’s over-reliance on CBA may be ignoring some important health benefits of different housing arrangements, particularly for low-income tenants,” Dr Moore said.
“Households living in the Catalyst houses reported they had extra spending money for Christmas presents, personal debt or holidays, due to low utility bills, with one household reported permanently removing itself from all Centrelink payments due to the amount they saved.
“These savings strongly contributed to reduced stress and better mental health for tenants.”
He said the DHHS could use the report to “validate the sustainable elements that deliver the best social, financial and environmental value in low-density public housing, and also better inform the housing sector about the link between green homes and tenant’s health”.