A Preliminary Ecological Appraisal (PEA) provides an initial assessment of ecological constraints and potential opportunities for a specific site. This typically involves a desk study (potentially including data from local records centers) and a comprehensive habitat survey. The scope may also include additional surveys, such as a Preliminary Roost Assessment, as required.

Where ecological constraints are minimal and no further surveys are deemed necessary, a PEA may be sufficient to support a planning application. However, if further surveys and assessments are required, the PEA will typically progress to a more detailed Ecological Impact Assessment.