The city of Basel, Switzerland has promoted the installation of green roofs through a number of various policies and schemes. Therefore the local authorities formulated two incentive programmes in order to provide subsidies for the installation of green roofs. Specific guidelines were introduced either for new or renovated flat roofs greater than 1,000 m2 which has to be green and a mandatory consultation with a city expert has to be undertaken. For instance, measures like use of specific local materials (like native flora and fauna etc.), precise definition the depth of the growing medium, use of native soil etc. are important elements to create a valuable habitat. It has been reported that more than 85,000 m2 of roof areas has converted to green since the late 1990s resulting in savings of 4 GW/year of energy (Drivers Jonas LLP and EDAW AECOM, 2009).