The market for extensive green roofs experienced a boom after 2004 when French society grew a strong awareness and support of developing solutions that respect the environment. In France, the concept of green roofs appeared in the 1990s. In the 90s, almost 15 % of the new green roofs created in Germany were planted using the extensive green-roof technique. This type of planting is economic in terms of resources (the selected plants have minimal water and maintenance requirements) as well as more representative of a natural system. Research into green roofs was conducted in Germany and a new concept appeared: extensive green roofing.Įxtensive green roofs are much thinner and lighter than the intensive roof garden systems. Due to an effect called the urban heat island, temperatures are often ten degrees higher in cities than in surrounding areas due to the heat absorption and retention of materials like asphalt and concrete. Planting a green roof for aesthetic reasons became popular later with roof gardens. Originally green roofs were popular as a technique associated with thermal regulation. Establishing plants on roofs is not a new concept.
