Seattle is another city in which green roofs have been used on an increasing basis. This phenomenon is in large part due to efforts on behalf of the city to encourage green roofs through new and improved building codes. In 2006, the Seattle Green Factor program was approved. The program rewards the incorporation of landscaping in new building developments in an attempt to reduce stormwater runoff and associated pollution, stabilize temperatures, and create habitats for birds and insects. These changes were expanded in 2009 to recognize the specific stormwater benefits of green roofs, and to reward developers who used them accordingly.