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By mid-afternoon in peak summer, the hottest place in an Indian city is often not outside but directly under a concrete roof, where heat absorbed through the day settles into walls and ceilings and lingers well into the night. For families living on the top floor, this makes sleep difficult, and the next day often begins in a state of exhaustion.
This persistent heat build-up inside homes makes passive cooling a necessity. Cool roofs, made with reflective coatings reduce heat absorption and can lower indoor temperatures by two to three degrees Celsius. For households without air conditioning, this is not simply a matter of comfort, as it affects sleep, productivity, and the risk of heat-related illness. Even in homes with cooling devices, lower heat absorption means less reliance on energy-intensive cooling, and lower electricity bills as a result.
The costs are not prohibitive, with basic coatings available at roughly Rs 20 to Rs 50 per square foot depending on product quality, requiring no electricity, no complex installation, and limited maintenance. Evidence from Indian cities suggests that the benefits outweigh the costs, a case that is increasingly reflected in policy. Telangana introduced India’s first state-wide cool roof policy in 2023, while national frameworks such as the India Cooling Action Plan and the Energy Conservation Building Code emphasise passive cooling. Cities such as Ahmedabad and Hyderabad have piloted programmes, and Tamil Nadu is scaling adoption across public buildings.
Yet uptake among low-income urban households remains low.
The usual explanation is a lack of awareness, but this is incomplete. The constraint lies not only in what people know, but in how decisions are made under financial pressure, timing constraints, and uneven incentives. This is reflected in Ahmedabad’s experience, where early pilots saw meaningful uptake driven by subsidies, direct engagement, and visible community adoption, while demand did not sustain itself once that support receded.
In early 2026, the Centre for Social and Behaviour Change at Ashoka University convened a workshop with NRDC India, bringing together around 20 participants from technical, policy, and communications teams. What emerged was a consistent pattern: households were often aware of heat risks and knew solutions existed, but could not act.
A closer look at household decisions helps explain why. Even modest upfront costs compete with daily expenses in households with limited flexibility, while the need to reapply coatings every few years adds to this hesitation. In many cases, the person paying for the roof is not the one most affected by the heat. Tenants endure the hottest months but have little reason to invest in a roof they do not own, while landlords see no immediate return.
Timing also works against adoption. Roof repairs are often planned after the monsoon, when the urgency of summer heat has faded. By the time temperatures rise again, the opportunity to act has passed, leaving a situation where the cost is immediate while the benefit feels distant. Decisions are also not purely functional, as homes reflect care, aspiration, and identity, and improvements are chosen not only for utility but for how they look and what they signal, meaning reflective coatings do not always align with these expectations and this affects uptake in subtle but important ways.
Decisions are ultimately made in specific moments that are poorly designed. In a typical visit to a neighbourhood paint shop before summer, a customer asks for the most affordable way to manage heat and is directed towards familiar products. Reflective coatings, even when available, are rarely highlighted or recommended. Within a brief interaction, the decision is made and the opportunity is lost.
Communication presents an additional challenge. Messaging around cool roofs often relies on broad claims such as temperature reductions or energy savings. While technically accurate, these are averaged across very different contexts. A household in a concrete-roofed structure without active cooling experiences the intervention differently from one already using a fan or evaporative cooler. Benefits are therefore real but context dependent, and general promises can feel too abstract to build trust without locally grounded expectations.
Addressing this does not require new technology, but a redesign of the context in which choices are made. Reflective coatings need to be visible alongside standard options, retailers require incentives and training to recommend them, and product positioning must align with what households value.
That said, redesigning the choice environment is only part of the solution. Subsidies remain necessary where upfront costs are unaffordable, access must improve where supply chains do not reach informal settlements, and building regulations need to extend beyond new construction to existing housing stock. Behavioural approaches are most effective once these constraints are addressed, by first making the choice possible and then making it easier.
India has recognised the importance of adapting to extreme heat, but adoption will not scale through policy intent or technical solutions alone. It will depend on aligning incentives, improving access, and redesigning everyday decision environments so that systems reflect how people actually make decisions. The paint shop is one such moment. There are many others, and most of them haven't been designed yet.
Anna Paul is a Behavioural Scientist at the Centre for Social and Behaviour Change, Ashoka University, Delhi-NCR
The views expressed are personal and do not reflect the views of the University or Down To Earth