Why White Rooftops Are Becoming Popular in Indian Cities

As Indian summers grow longer and hotter, especially in cities packed with concrete and metal, beating the heat is becoming harder — and more expensive. Air conditioners aren’t always an option, especially for low-income families. That’s why a surprisingly simple idea is catching on in many parts of the country: painting rooftops white.

It may sound too easy to work, but this technique — called cool roofing — is helping homes stay a few degrees cooler without using a single unit of electricity. It’s affordable, low-tech, and making a real difference.

So, what exactly is a cool roof?

Think of it like this: On a sunny day, wearing black makes you feel hotter, right? That’s because dark colours absorb more heat. Now, imagine your roof doing the same thing. A regular concrete or metal roof can heat up to 65°C or more. But a white-painted roof? It can be up to 28°C cooler.

That’s the whole idea behind a cool roof. By applying a special white or reflective paint, rooftops bounce sunlight away instead of soaking it in. The result? Cooler rooms underneath, even without fans or ACs running all day.

What’s the big deal? Turns out, a lot

For families in small or poorly ventilated homes, even a 2–5°C drop indoors can be a game-changer. Here’s what cool roofs are helping with:

• Lower indoor temperatures: This is the most immediate benefit. Homes become noticeably more bearable during the hottest hours.
  
• Reduced electricity bills: Less need for fans and coolers means more money saved.
  
• Better sleep and comfort: Residents report sleeping better and feeling less fatigued.
  
• Environmental impact: Using less electricity also means fewer emissions. It’s good for your home and good for the planet.
  
• Tackling the “urban heat island” effect: Cities tend to trap more heat than rural areas. White rooftops help reflect some of that heat away.

Real results from Indian cities

This isn’t just theory — it’s already happening on the ground.

• Ahmedabad, Gujarat: In the Vanzara Vas slum, over 400 homes had their roofs painted with a white coating containing titanium dioxide. The results were immediate — families slept better, used fewer fans, and felt a real change in comfort. The project was part of a study to understand how indoor heat affects people’s health and finances.
  
• Telangana: In 2023, the state became the first in India to launch a Cool Roof Policy. It mandates white roofing for all government and commercial buildings and encourages it in homes. It’s a bold, state-wide move to tackle urban heat head-on.
  
• Delhi: The Mahila Housing Trust, along with the University of Chicago’s Energy Policy Institute (EPIC), has been helping residents in resettlement colonies apply cool roof paint. Even in tightly packed neighbourhoods, people reported lower indoor temperatures and smaller electricity bills.
  

Similar projects are underway in cities like Surat, Bhopal, Jodhpur, and Ahmedabad — many supported by the Mahila Housing Trust and the Natural Resources Defense Council (NRDC) and focused on low-income neighbourhoods that suffer the most during heatwaves.

What does it take to paint a cool roof?

It’s easier than you might think. Here’s a quick breakdown:

• Pick the right day: Choose a sunny, dry day so the paint can dry properly.
  
• Clean the surface: Use a wire brush or water jet to clear out dust and dirt.
  
• Repair cracks: Make sure the roof is in good shape before painting.
  
• Apply primer (if needed): Some paints require a base coat — check the instructions.
  
• Paint the roof: Use a roller, brush, or spray to apply the reflective paint evenly.
  
• Let it dry: Most paints dry within 24 hours.

And that’s it. No special equipment, no high-end tools. While many residents apply it themselves, some community efforts involve volunteers or local contractors to help with the work.

A few things to keep in mind

Cool roofs work best in hot regions. In cooler areas, they could make homes chillier in winter. They also need a bit of upkeep — dirt and dust can reduce their reflective power, so occasional cleaning helps.

And not all paints are the same. High-quality reflective coatings work better and last longer, so it’s worth choosing wisely. Most coatings last anywhere between two to five years, depending on quality and local weather conditions.

A simple fix that works

Cool roofs won’t solve all our climate problems — but they don’t need to. What they offer is an affordable, immediate way to stay safe and comfortable in rising heat, especially for those who can’t afford air conditioning. And when enough homes in a neighbourhood adopt this, the whole area feels a little cooler.

In a world chasing high-tech climate fixes, this quiet, white-roof revolution is proof that sometimes, the simplest ideas shine the brightest. And if more cities take Telangana’s lead, cool roofs could become a nationwide tool for building climate resilience — starting from the top down.

Edited by Khushi Arora and Vidya Gowri