Book excerpt: Although methodologies for classification, quantification, and valuation of ecosystem services are improving drastically, applications of the ecosystem services concept in day-to-day decision-making processes remain limited, especially at the planning level. Nevertheless, spatial planning decisions would benefit from systematic considerations of their effects on ecosystem services. Assessing the impacts of policy on a wide range of ecosystem services contributes to more cost-effective policy implementation, establishing win-win situations across different environmental domains. The “nature value explorer” (natuurwaardeverkenner in Dutch) is a web application developed to explore the quantity and value of ecosystem services in Flanders, Belgium, as part of environmental impact assessments. The tool estimates the impact of land-use and land-cover change on regulating and cultural ecosystem services. The web application is successful in drawing the interest of policy makers and is used in several cases to support decisions in infrastructural projects as well as nature restoration projects.