White Paint Drops Indoor Temps 6°C in Ahmedabad Slums

When temperatures hit 45°C in Ahmedabad, Sangeeta Ben's tin-roof home became an oven that stole her ability to work and provide for her family of ten.

The 30-year-old stitching worker earns Rs 150 daily operating a sewing machine, but during summer months, the unbearable indoor heat cut her productivity dramatically. Air conditioning costs thousands of rupees she simply doesn't have.

Then something remarkable happened. Workers arrived at her Sadgurukrupa Slum home and painted her roof white with a special solar reflective coating made with Titanium Oxide.

The paint works by bouncing sunlight back instead of absorbing it as heat. Two coats are applied in perpendicular directions, with two hours drying time between layers, ensuring complete coverage and maximum cooling power.

"Since we applied the solar reflective white paint, the difference in temperature indoors is remarkable," Sangeeta told The Better India. She can now work longer hours comfortably in her own home.

The Cool Roofs Programme launched in March 2025 across India's hottest cities, with Ahmedabad leading a global pilot study. Mahila Housing Trust manages the initiative, which targets vulnerable communities living in informal settlements where tin and asbestos roofs trap dangerous levels of heat.

The science backs up what families are feeling. Research shows these treated roofs drop indoor temperatures by 3 to 6 degrees Celsius compared to untreated surfaces, transforming living conditions for millions facing climate change's harshest impacts.

"Our measurements show a remarkable temperature difference of 3 to 6 degrees after installing cool roof technology," confirms Dipika Vadgama, Programme Manager at Mahila Housing Trust. The paint is also water-based with low VOC emissions, making it safe and environmentally friendly.

The Ripple Effect

The cooling benefits extend far beyond comfort. Women working from home, who bear the brunt of extreme indoor heat, can now maintain their livelihoods during brutal summer months. Families report better sleep, reduced heat-related illness, and children who can study without suffering.

Long-term exposure to extreme indoor heat causes heatstroke, chronic fatigue, insomnia, and high blood pressure. For low-income communities on the frontlines of climate change, this affordable intervention addresses a life-threatening crisis that worsens each year.

The programme demonstrates how simple, locally applicable solutions can protect vulnerable populations without requiring expensive infrastructure or technology. As heatwaves intensify across India, cool roofs offer a dignified path forward for communities that need relief most.

Thousands of families across Ahmedabad's slums now sleep easier knowing a humble coat of paint stands between them and dangerous heat.