There is a phenomenon called the ‘Urban Heat Island Effect’, where built up areas are significantly hotter than rural areas. In part, it’s caused by replacing vegetation with heat absorbing materials like concrete buildings and tar.

Due to the topographical shape of Sydney, Western Sydney suffers quite severely from Urban Heat Island Effect. It can be up to 10^oC hotter than the city during a heat wave, and this has significant impacts on the community. For example, you’re 3 times more likely to die from the heat in Western Sydney than you are closer to the coast. You’re electricity demand is also 100% greater during heat waves, which means higher electricity costs and greater risk of blackouts (Guide to Urban Cooling Strategies, 2017).

I love Western Sydney, and this is not the future that I want. So I’ve come up with a plan.

The White Roof Revolution

Do you know the feeling of jumping into a black car on a really hot day, and wishing it was white? The same thing happens with our buildings. Dark-coloured roofs can be up to 30^oC hotter than lighter roofs as they absorb much more of the sun’s rays.

This matters for three reasons: comfort, cost and community.

Comfort: Your home can be 4.7^oC cooler with a white roof than a dark roof – and that’s a big difference during a heatwave. It’s the really extreme temperatures that kill vulnerable people like our elderly, so 4.7^oC really matters.

Cost: That same temperature difference can also save up to 34% on your air conditioning cost. With electricity prices so high, that can mean a lot to marginalised people.

Community: Where every roof in your street is black, this heat load impacts your ability to safely walk along the streets during hot days, increasing isolation and obesity.

White roofs don’t just benefit homes – they’re a solution for every type of building. DHL Supply Chain has painted Sky Cool, a reflective white paint, on some of their existing warehouses, and reduced their energy bill by 25%, saving more than $40,000 a year.

The vision

I want to turn every roof in Western Sydney white.

A lot of quality research has been undertaken to date, such as by the CRC for Low Carbon Living and Western Sydney Region of Councils. There’s a disconnect between the work done by institutions and government and the decisions that are made on the ground by developers, builders and ‘mums and dads’ who are making the best decision they can with the information that they have.

The solution could look like policy recommendations, guerrilla roof painters (like this group in New York) or a commitment from companies to only install white roofs in exchange for a discount. My aim is to understand how roof-colour decisions are made by undertaking interviews, and develop solutions driven by the problem.

Join me!

If you have any ideas related to this or want to get involved, comment below. I’d also love to hear your ideas for making the world a little better!