Identifying suitable policy instruments to promote nature-based solutions in urban plans

Urban plans can promote the implementation and scaling up of nature-based solutions (NbS) through the adoption of specific policy instruments. These can be applied to different typologies of NbS interventions, depending on the transformations allowed by the plan and property regime of the different areas. Through a review of real-world applications, we provide an overview of policy instruments that can be used to promote NbS implementation in urban plans. We identify eighteen types of policy instruments divided into five main categories and linked them to eight overall typologies of NbS interventions to which they can be applied. The matrix linking policy instruments and NbS interventions includes fifty-nine matches corresponding to documented real-life applications. Regulations can be especially used to integrate NbS early on in new development areas, while incentive-based instruments are suitable to promote NbS in retrofitting and renovating the built environment. Notably, more than one instrument can be applied to each NbS typology. We discuss the differences among the instruments and how they can be combined to achieve the desired policy goals. Moreover, we illustrate how the matrix can be used to expand the range of policy options in a specific planning context, supporting a wider implementation and scaling up of NbS through urban planning.