The appropriate evaluation is a mandatory evaluation for projects or plans in or in the neighbourhood of Natura 2000 sites (Birds and Habitats Directives). This evaluation assesses whether the projects or the plans have or do not have any possibly significant effects on the protected species and the habitat types in those sites. A number of steps are passed through for the purpose. In case of uncertainty or in case of significant adverse effects, one must first examine the alternative solutions. In the absence of alternatives that are not harmful, the plan or the project cannot be implemented unless there are "compelling reasons of public interest". Even then, certain conditions apply.
More information about the appropriate evaluation can be found in the document "Management of "Natura 2000” sites - The provisions of Article 6 of the Habitats Directive (Directive 92/43/EEC)" of the European Union.