White roofs can cool down homes – but scaling up this simple solution is a challenge

In the last few years, Sahani Begum found that the desert cooler she owned was barely effective enough. Her small, two-storeyed home in RK Puram’s Hanuman Labour Basti in New Delhi would become unbearable in the summers, the temperature inside rising much higher than outside.

Then, her son heard about a quick and simple solution through the internet – painting their roof white. have found that applying reflective white paint on cemented roofs can reflect between 30% and 70% of direct sunlight, significantly reducing indoor temperatures.

Begum’s son bought the paint and finished painting two coats on the roof in a single day. They felt the difference immediately. “We could sleep in relief,” Begum, who is in her fifties, told Scroll.

As heatwaves become more frequent and intense in India, experts say it is no longer enough to simply avoid direct exposure to the sun – even indoor heat poses a risk to human health.

In fact, during summers, depending on the material used for construction, temperatures inside buildings can be as much as 12 degrees Celsius higher than outside, said Bharati Chaturvedi, director at Chintan, a non-profit that works on waste management and livelihoods.

In Delhi, low-income communities that cannot afford air-conditioning are experimenting with small-scale, low-cost solutions like...