From antiquity to the roofs of the great metropolises…
Cool Roofing, or toiture fraîche in French, is a construction technique that consists of covering the roofs of buildings with materials reflecting the heat of the sun, in order to reduce the absorption of heat by the building and thus reduce the interior temperature. This technique has been used since antiquity and is experiencing a revival of interest today.
The history of Cool Roofing goes back to ancient times, when the Greeks and Romans used white marble roofs to reflect the heat.
The white colour of ancient Mediterranean houses was often the result of the availability and simplicity of building materials, as well as their effectiveness in keeping houses cool during hot summer days. This construction tradition has continued to the present day, and many houses in the Mediterranean region are still built with white materials to allow them to stay cool during the summer months.
Today, Cool Roofing has become a common construction technique in urban areas and is used in a variety of buildings, such as homes, schools, shopping malls and office buildings. Cool Roofing roofs are covered with materials such as reflective paints, ceramic tiles, metal panels and white roofing membranes.
The advantages of Cool Roofing are many. First, it reduces the indoor temperature of the building, which can reduce the demand for air conditioning and therefore energy costs. In addition, it can help reduce the formation of urban heat islands, which are areas where the temperature is higher than in surrounding areas due to heat absorption by buildings. Cool Roofing roofs can also last longer than traditional roofs because they are less subject to temperature and humidity variations.
The IPCC (Intergovernmental Panel on Climate Change) says that "painting roofs white would save 1 Gt/year in greenhouse gas emissions, equivalent to 250 million vehicles", and that it is one of the fastest and cheapest solutions to adapt and mitigate climate change.
According to a study conducted by the Lawrence Berkeley National Laboratory in 2020, the total area of Cool Roofing roofs installed in the United States is estimated to be about 3.7 billion square metres. This represents a significant increase compared to previous years, with an average annual growth of almost 40% since 2014. In Europe, these values of high thermal emissivity (91%) and high solar reflection (83%) of THERMO-REFLECT® allow it to cool roofs. In summer, the roof remains colder, the amount of heat transferred into the building is reduced, thus maintaining a colder and more constant interior temperature. Thermal comfort inside buildings is improved and air conditioning needs are reduced.
Unlike other cool roofing processes that can have negative effects on winter energy consumption in colder regions (as they also reduce the absorption of solar heat that could help heat the building) THERMO-REFLECT® is also insulating! In cold periods, it will keep the heat in the building and keep the cold outside.
THERMO-REFLECT® brings the benefits of Cool Roof and thermal insulation in one product. It improves the thermal comfort of buildings and saves energy throughout the year.
This technique is also increasingly used, especially in hot countries such as Spain, Italy, and Greece.