Green roofs in Tampere. The private developers and building owners support the NBS implementation by setting up green roofs on their properties. Such private sector efforts are mostly guided by the municipal policies that require the construction companies to include a certain amount of green area in their new buildings. The municipality in Tampere has also introduced new planning tools like the Green Factor, which accounts for the green areas in land use and construction projects and thus facilitates the implementation of the NBS policy guidelines.