The New South Wales government has abandoned its plan to ban dark roofs – aimed at reducing temperatures and energy costs for new homes – as the state’s new planning minister walks back ambitious sustainability measures announced by his predecessor.
Former planning minister Rob Stokes previously announced he would be tasking the Department of Planning and Environment with implementing a requirement for lighter-coloured roofs in all new homes in the state, and that the policy feature would help NSW achieve its goal of net zero emissions by 2050.
“This would have an enormous impact on the urban heat island effect in our city,” Stokes told a forum run by urban thinktank Committee for Sydney in November.
“There are no practical reasons why we shouldn’t be ditching dark roofing on new homes permanently to ensure that future communities of Sydney’s west don’t experience the urban heat that many communities do now,” he said.
The dark roof ban was one of many ideas announced by Stokes as part of his sustainable planning agenda, which also included a Design and Place State Environmental Planning Policy (Sepp) as its centrepiece.
The wide-ranging set of rules in the Design and Place Sepp – which is separate to the dark roof ban – were to push commercial buildings to be net zero carbon emissions from day one, see apartment blocks built with electric vehicle charging stations, require minimum tree cover for housing developments and push for walkable suburbs, among other requirements that had been praised by environmental groups.
This week, the new planning minister, Anthony Roberts – who succeeded Stokes after he was demoted from the role by premier Dominic Perrottet – announced he would not introduce the Design and Place Sepp, after the cost and regulatory burden of adhering to the policy was fiercely criticised by property developers during its public exhibition period.
Guardian Australia can reveal that while the plan to require lighter-coloured roofs was not part of the proposed Design and Place Sepp, the ban appears to have been another sustainability idea scrapped since its announcement.
When Guardian Australia contacted Roberts’s office to clarify the status of the dark roof ban, his office referred questions to the NSW Department of Planning and Environment. A department policy director told Guardian Australia that no measures to ban dark roofs were on the horizon.
Instead, the policy director said that updated energy efficiency rules for new dwellings had been proposed to disincentivise, not ban, dark roofs.
The rules would force developers wanting to build a home with dark roofing to include greater efficiencies in other features of the dwelling to offset its negative impact – such as insulation or a reflective finish on a roof surface to reduce solar absorbency – to achieve a passable Building Sustainability Index (Basix) score needed for planning approval.
Dr Sebastian Pfautsch, an associate professor of urban studies at Western Sydney University who has studied urban heat, said that the fact the government had stalled in banning dark roofs reflected “the absurdity of where developers place their preferences these days”.
Pfautsch said the benefit of lighter roofs was “undisputed among anyone who has any idea of how heat works”.
He said dark roofs contribute to the “urban heat island” effect, where apparent outdoor temperatures are hotter because dark surfaces built on new developments, such as bitumen and roofs, absorb and radiate heat into homes and into the air on the streets.
In western Sydney, a light-coloured roof could reduce temperatures inside the home by 4C on average and up to 10C during a heatwave, compared with darker roofing, according to research commissioned by the federal government. Street temperatures can increase by up to 4C during a heatwave because of the heat island effect.
Pfautsch said air conditioning also contributes to the heat island effect because systems pump out hot air on to streets – an increasingly common reliance in new housing developments on the outskirts of major cities which lack significant natural shade and tree cover.
“It’s a vicious cycle, because even if planners offset the effect of a dark roof inside the home with insulation, it still has an effect on making the surrounding environment hotter – you’re radiating the heat,” he said.
“It’s so disappointing to think of how many hundreds of thousands of homes are going to be built like this,” Pfautsch said.
Sam Kernaghan, the Committee for Sydney’s resilience program director, said “removing the ban on dark roofs for new housing would be a significant step in the wrong direction”.
“Of all the things that can be done about the problem of living with extreme heat in western Sydney, the easiest is requiring light-coloured roofs. It’s not the whole solution, but it’s a step in the right direction,” he said.
“The NSW government needs to stay the course on dark roofs, and send a clear message to residents of new growth areas that they care about the quality of housing being built across Sydney, not just the quantity,” Kernaghan said.
Paul Scully, the NSW Labor opposition planning spokesperson, said “the NSW government needs to come clean with precisely which planning policies it remains committed to and how scrapping measures aimed at addressing climate change in the built environment will achieve their net zero by 2050 target”.
“Another week, another component of the NSW government’s net zero commitment appears to have fallen by the way side,” Scully said.
