HRA applies to European sites considered as:
- Special Protection Areas (SPA) classified under the Birds Directive
- Special Areas of Conservation (SAC) classified under the Habitats Directive and ‘candidate’ SAC
For a proposal to potentially affect a site, there has to be a link or connection between the:
- qualifying interests of the site
- changes that a proposal may cause.
It's not possible to produce a list of plans or projects that must always be subject to appraisal and those that will not.
Neither the European Commission Directives or the Habitats Regulations define the scope of either plan or project by reference to particular categories.
Instead, the key limiting factor is whether a plan or project could undermine the conservation objectives of the qualifying features for which the site was classified.