Preliminary Ecological Appraisal (PEA)

Used extensively, often as one of the first site surveys to establish planning constraints, a Phase 1 Habitat Survey (P1HS), Extended P1HS or Preliminary Ecological Appraisal (PEA) Biodiversity survey is a baseline appraisal of a site’s ecology.

The Preliminary Ecological Appraisal (PEA) is a type of Biodiversity Survey and includes a desk study, site survey and report, and should be undertaken as early as possible in the planning process. The report categorises the habitats on the site, determines whether the site is likely to support protected species and provides an assessment of potential ecological constraints to development.

In addition to holding Natural England protected species licences, our in-house staff are in the enviable position of having excellent botanical skills, which means our habitat surveys and ecological appraisals are robust and will withstand close professional scrutiny, even to the level of Public Inquiry if required.

Phase 1 Habitat Surveys

The difference between a standard Phase 1 Habitat Survey (JNCC 2010) and an Extended Phase 1 Habitat Survey is usually understood to be the inclusion of protected species, and their association with the mapped and observed habitats on the ground. A Preliminary Ecological Appraisal also includes opportunity to deliver ecological enhancement, as well as highlighting ecological constraints, mitigation measures and the need for any further surveys.

Perhaps the most useful output from these types of ecological surveys are the ‘target notes’ which pin-point potential ecological constraints within the site boundary, and occasionally just outside the curtilage. Each target note is specific to an identified risk to development, such as; invasive weeds, nesting birds, badger etc., and these constraints can then be used to start informing a planning application.

Protected Species Surveys

Frequently, the Preliminary Ecological Appraisal is used to inform secondary surveys for protected species which may have seasonal constraints to survey associated with them, such as bats. For example, if bat droppings are present within a building on the site scheduled for demolition, then planning permission is unlikely to be granted until a bat survey has been undertaken. An Extended P1HS or Preliminary Ecological Appraisal will identify this risk to project delivery, and allow recommendations for further work to be made.

If no potential ecological constraints are found to be present, the client can of course use the survey as evidence, in its own right, to be taken forward in the planning process.

If you are uncertain what type of survey is needed for your site, please contact us and we will be pleased to explain and talk through the various options.

We undertake Preliminary Ecological Appraisals throughout Yorkshire and the Yorkshire Dales, Derbyshire, Teesside and Tyneside.


CIEEM Guidelines for Preliminary Ecological Appraisal
Guidelines-for-Preliminary-Ecological-Appraisal-Jan2018-1.pdf (cieem.net)