Summer in India’s northwestern metropolis of Ahmedabad was never easy for Meenaben Soni. Soni, who lives with her family in a cramped two-bedroom house in the city’s informal settlement of Vishwasnagar, struggled to perform her work as a tailor as temperatures regularly hit upwards of 40 degrees Celsius – that’s 104 Fahrenheit – in the arid state of Gujarat for months at a time.

Given her tin-roofed home, she says, “(I) struggled to sit next to my sewing machine and lost out on work,” even with access to ceiling fans and electricity.

Things changed for the seamstress when Soni chanced upon the concept of “cool roofs” in 2016. Along with other women from her community, she had been invited to attend meetings organized by the Mahila Housing Trust (MHT), an Indian nonprofit that works with low-income women to build climate-resilient homes.

The MHT helped them replace their tin roofs with the organization’s modular roofing system, ModRoof. Produced out of packaging and agricultural waste, it allows for ease of installation, construction and replacement of individual panels.

The ModRoof is also waterproof and durable — and reusable, making it more cost-effective for residents. If residents wish to add additional floors to their home, the existing roof can be replaced on the new top floor; if they move to a different home, they can bring the roof with them.

Today, seven years since first raising a loan to invest in a ModRoof, the temperature of Soni’s home has decreased by nearly 6 degrees Celsius – about 11 degrees Fahrenheit. Where once she had to use three fans to maintain temperatures, today she uses only one ceiling fan. Her monthly electricity bills too, have halved from 1000-1,200 Indian rupees down to 500-600 Indian rupees (from about $12-14 USD down to $6-7).

“There was a risk of heat-stroke earlier,” Soni tells Next City. “My husband hasn’t been admitted to the hospital after we installed the ModRoof. Our children can also study in comfort. The neighborhood’s other children also come to our house to study. I can see our dreams slowly coming true.”

Established in 1994, the Mahila Housing Trust was formed with the help of the Self Employed Women’s Association (SEWA), a collective of over 2.5 million informal women workers and representatives across India. Envisioned as a project to improve housing and infrastructural conditions of lower-income women in the informal economy, its efforts are funded by partnerships, donations and grants. In addition to building climate-resilient and energy-efficient housing, its work today includes securing equitable access to water and sanitation, microlending initiatives, improving community infrastructure and participatory governance.

As temperatures rise across the world, India remains one of the biggest victims of heat stress. In 2022, a World Bank report claimed that from 2030, over 160 to 200 million people would risk being exposed to a lethal heatwave in India every year. Moreover, nearly 34 million Indians are likely to face job losses owing to the impact of heat stress on productivity. The same year, India was forced to ban its wheat exports thanks to a devastating heat wave affecting crop production and local prices.

The vast majority of the country’s poor and lower-income communities who live in crowded informal settlements face the biggest brunt of this heat stress, which is expected to worsen with climate change. Meanwhile, new research carried out by a group of scientists from 10 countries found that climate change made last year’s April heatwave in India 30 times more likely. In fact, nearly 17,000 people in the region have died due to heat stress between 1971 and 2019.

One such deadly heat wave occurred over a decade ago in the city of Ahmedabad, back in May 2010. Temperatures crossed 48 degrees Celsius, leaving more than 800 people dead. The scale of loss forced the city’s administration to adopt the first ‘Heat Action Plan’ in 2013, devising a warning system and collaborating with nonprofits like the MHT to build sustainable homes for the region’s most vulnerable communities.

Today, the MHT is working with lower-income groups across the country as they build climate-resilient homes for the poor and most disproportionately affected. This includes bringing in cost-efficient modular roofs, reflective white paint and insulated ceilings to lower-income homes. With more than 30,000 cool roofs or modular roofing systems installed across nine Indian states, the organization also collectivizes women residing in informal settlements by conducting training sessions and workshops on climate change and measures to tackle heat stress. In the northern Indian state of Rajasthan, MHT notified women in the city of Jodhpur about a heat wave through color-coded alerts displayed on street posters and sent to their cellphones.

Experimenting with sustainable alternatives

For women like Dipikaben Mallik, painting her roof with solar reflective white paint changed the temperature of her home by “nearly 4 or 5 degrees.” Priced at an affordable 300 rupees ($3.6 USD) per liter, MHT provided the paint to over 963 homes in informal settlements to cool their roofs. Mallik, who has so far painted only one of her rooms, says she wants to “paint the entire roof of the house with the solar reflective paint, and get most of its benefits.”

The paint contains specialized pigments with high solar reflecting and thermal emitting powers, making it a more climate-friendly alternative than normal paints on the external walls of houses.

Low-cost measures like this have helped these women to live and work in comfort. The ability to focus on their work without exertion thanks to heat stress has also led to an increase in productivity. Moreover, their children can study in the comfort of their homes. Residents in these settlements have also reported that their usage of fans and coolers has reduced which has, in turn, reduced their electricity bills.

A 2022 study by the University of New South Wales found that switching to ‘cool roofing’ could lower interior temperatures and reduce energy bills. “More than 250 cool roof technology projects around the world have succeeded in decreasing city average air temperatures by 2.5°C to 4°C,” researchers explained. “And there are new technologies in development that will be able to decrease by 5°C.”

Meanwhile, other studies looking into the impact of reflective, white-painted cool roofed schools in both India and Greece found that indoor temperatures dropped by 1.5-2 degrees Celsius and 1.3-2.3 degrees Celsius respectively. Though there’s no conclusive proof that these measures are the most effective in the long run, the response has so far been positive.

For 54-year-old Lakshmiben Gohil, living with her son, daughter-in-law and three grandkids in a cramped settlement in Ahmedabad’s Rajiv Nagar has never been easy. Gohil, who makes a living by running a small grocery shop from her home, struggled to sit at the shop counter for long hours. Her home-cum-shop’s tin sheet roof attracted high temperatures during summers, causing exhaustion. The Trust helped Lakshmiben’s family in constructing a bamboo roof at her house and installed a door made of bamboo fiber.

“More than a year ago, we got the bamboo roof installed,” says Lakshmiben. “Since then our home remains cooler even during the hot summer months. Rain-water leakage has also stopped.”

Bamboo roofs are another renewable solution to combat heat waves. Made of resin-coated bamboo mats which are pressed to form a strong lightweight structure, these roofs are locally sourced. One recent study claims that bamboo-based roofs could make homes as much as 7 degrees Celsius cooler than regular sheet-metal roofs, but even as more research emerges, women like Lakshmiben claim that this alternative has also curbed rainwater ingress from the roof.

“We have been using only one fan for the past one year, which has reduced our electricity bills,” she adds.

Meanwhile, as temperatures continue to soar, the organization intends to continue working on heat-resilient housing by installing at least 5,000 more cool roofs across India by 2026.

Today, they’re also fostering a culture towards sustainability amongst these women, training them in rainwater harvesting, composting techniques, and using fuel-efficient stoves to reduce reliance on firewood.

By focusing on women, the MHT believes that their work towards sustainability has a longer lasting effect, explains Bijal Brahmbhatt, the director of the organization.

“Long-drawn climate change stresses are painful and have an inter-generational effect. When we involve women and adolescent girls, we can make sure that the work we do will benefit generations,” Brahmbhatt says.