As Heatwaves Intensify, NOVA Urges Building Professionals to “Choose Cool Roofs”

The Nova Paint Club, an alliance of the world’s leading independent paint companies, has launched the “Cool Roof, Smart Choice” campaign to accelerate the adoption of reflective roofing solutions by building professionals to address the growing problem of extreme heat. Globally, heat-related deaths have increased by 23% since the 1990s to about 546,000 a year – about one every minute. As scientists warn of another year of record-breaking heat, driven by a strong El Niño, the need for scalable cooling solutions has become increasingly urgent.

Cool roofs are a simple and cost-effective way to adapt to a future where extreme heat events are growing in frequency and intensity. They reflect more sunlight and absorb less heat than dark colored roofs, which are prevalent in many parts of the world. Dark roofs absorb heat and raise temperatures for buildings, which then requires large air conditioning (AC) units to vent the heat out. In urban areas, they contribute to the urban heat island effect, where city temperatures can be 4 to 10ºC higher than surrounding regions, leading to more heat-related deaths.

However, by applying a high solar reflective coating, a warming roof can be instantly transformed into a cooling roof that can cool lower indoor temperatures, create safer and healthier conditions, reduce energy demand, and mitigate urban heat buildup in a practical and cost-effective way.

“Every colour choice matters. The colours used on our roofs and buildings can make cities warmer or cooler, affecting energy use, comfort, and resilience to rising temperatures.” said Joao Luis Serrenho, President of Nova. “We want to empower building professionals with the knowledge to make smarter choices that benefit both people and the planet.”

The Power Of Reflection

The past three years (2023-25) have been the warmest years on record, and half the world’s population experienced at least one extra month of extreme heat in the year ending May 2025. Extreme heat is now the deadliest weather hazard, and heat related deaths are projected to surge by 370% by mid-century if no major urban adaptations are undertaken.

“Extreme heat is a significant health risk in our cities,” says Dr. Aditi Bunker, an epidemiologist at the University of Heidelberg in Germany who has been doing global studies on cool roofs and health. “As temperatures continue to rise, adapting to heat is becoming a public health priority. Cool roofs are an example of an evidence-based solution that can reduce indoor heat exposure, thus improving health, wellbeing and comfort of people exposed to extreme heat.”

Cool roofs have been shown to lower internal temperatures by 2-5ºC, making it more comfortable for students to learn, workers to be more productive, and for people to sleep better at night. They also lessen the thermal stress on roofing materials and improve the efficiency of solar panels. They offer an accessible cooling solution for low-income communities, who are disproportionately exposed to severe overheating and cannot afford air conditioning.

For buildings with AC, cool roofs can act as a passive shield to reduce a building’s cooling load. Dr. Hashem Akbari, founding leader of the Heat Island group at the Lawrence Berkeley National Laboratory (LBNL), estimates that increasing the reflectivity of roofs from a dark gray to an aged white could reduce annual cooling energy for the area just under the roof by 10–20%. Since they lower energy use at the hottest time of the day when electricity rates are often highest, building owners can generate substantial financial savings not just from lower energy use, but from lower peak energy demand, which is usually a large portion of the total utility bill. A study of Dr. Akbari showed that cool roof coatings can reduce a building’s cooling load by 18-93% and peak cooling demand by 11-27% in air conditioned residential buildings across different cities around the world.

“For building professionals, cool roofs are not only climate-smart but business-smart,” says Paolo Giaccone, Secretary General of Nova, whose members are spread out in Europe, Asia and the Americas. “As temperatures get higher, keeping heat out will be fundamental to building design. Cool roofs are a simple way to build in heat resiliency and future proof buildings that will need more cooling without using energy.”

“They lower operating costs for clients, extend roof life and can help get ahead of future building regulations to address extreme heat,” he adds. “Whether it’s retrofitting a school or designing a new residential complex, cool roofs deliver immediate and long-term value.”

Cool roofs will be especially valuable in cities, which are heating up about twice as fast as the global average due to factors like the urban heat island effect. Given that roofs make up about 20-25% of a city’s area, cool roofs can effectively counter the urban heat island effect if deployed on a large scale. In Almeria, Spain, white roofed greenhouses covering 26,000 hectares has resulted in a greenhouse cooling effect where the local temperature dropped by 0.7ºC over 23 years, while the surrounding areas warmed by 1ºC over the same period – a net difference of 1.7ºC. Lower urban temperatures would also considerably reduce the production of smog, resulting in healthier air for residents.

Installing cool roofs at scale would also reduce peak energy demand across a city, keeping the most costly and polluting power plants offline, minimize grid failures, and defer investment for infrastructure upgrades and new power plants. This translates to a lower energy bill and carbon footprint not just for buildings with cool roofs, but savings for the whole community.

In addition to “saving” carbon dioxide (CO₂) from lower energy use, cool roofs also directly cool the globe, reflecting short-wave radiation from the sun back into outer space where it cannot be trapped by greenhouse gases. As the world’s glaciers and sea ice melt at increasing rates, the Earth is becoming less reflective, trapping more heat in our planet. By reducing the heat absorbed by the Earth, cool roofs lower surface temperatures so less heat flows into the atmosphere. Dr. Akbari, who has continued his pioneering work on urban heat islands and reflective surfaces at Concordia University in Montreal since 2009, estimates that every 1 square meter of a white roof replacing a dark roof can offset the climate warming effect of 280 kg of CO₂ – i.e. it takes about 4 m² of white roof to offset 1 ton of emitted CO₂.

“Surface reflectivity does not remove any CO₂ from the atmosphere, but it does cool the Earth as though there were less CO₂ in the atmosphere,” says Akbari, whose methods of calculating how changes in albedo can offset CO₂ emissions hold potential applications in carbon accounting systems. “Put it simply, cool roofs cool the globe. It doesn’t solve the problem of climate change, but it buys us time.”

“The beauty of cool surface technology is that we have thousands of years of experience with it, and we do not know of any negative impacts associated with it,” Akbari adds. “There is very little incremental cost, if any, it improves ambient conditions within the city while it cools the planet, and it puts money in your pocket.”

“Using cool roof coatings to help people and the planet mitigate and adapt to the growing problem of extreme heat is a prime example of the power of coatings to benefit society,” says Johnson Ongking, campaign leader for Nova. “It’s an important dimension to how the coatings industry can contribute to sustainability. One cool roof can cool a home. Thousands can cool a city. Millions can cool our planet.”

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