Planted roofs have long belonged to the canon of environmentally friendly construction, and the topic is addressed by research organizations in many different countries today. The technology of green roofs has proved applicable to all climatic zones of the world. Germany leads the field in this respect, at least quantitatively. Since the boom in planted roofs in the 1980s, they have become a requirement in many local authority plans as a means of compensating for new building projects. In 2008, the FLL, a German research organization for landscape development, drew up guidelines for a permanent form of planted roof construction, providing architects and clients with a safe basis for the technical execution. Comparable guidelines exist in other countries, too. (Manfred Köhler)