Preliminary Ecological Appraisal Guide

What is a Preliminary Ecological Appraisal?

A Preliminary Ecological Appraisal (PEA) is a type of biodiversity survey.

Preliminary Ecological Appraisal is sometimes referred to as an Extended Phase 1 Habitat Survey or Phase 1 Ecology Survey, and is the first stage in assessing the ecological value of a site and enables identification of features of particular ecological interest.

The appraisal comprises a rapid assessment to identify features of ecological interest on-site or within the vicinity of the site to understand the potential ecological impacts that may be caused by a proposed project.

The rapid assessment includes:

  • A desk study to provide background data and context.

  • A walkover of the site is completed to classify and map the habitat types that are present.

  • Looking for evidence of or potential for protected species within or adjacent to the site.

A Preliminary Ecological Appraisal can be undertaken at any time of the year, although the optimal time for the Phase 1 Habitat Survey is from April to September, inclusive.

Objectives of a Preliminary Ecological Appraisal

The objectives of a Preliminary Ecological Appraisal are to:

  • Identify potential ecological constraints in relation to the proposed project;

  • Identify the need for further ecological survey;

  • Identify any mitigation measures which may be required; and

  • Identify opportunities for ecological enhancement within the proposals.

Why are Preliminary Ecological Appraisals Important?

Preliminary Ecological Appraisals are important as they help to identify and evaluate any features of ecological interest on a proposed development site. This identification is often required before planning applications can be submitted, as it can help ensure any mitigation measures are put in place before a proposed project is signed off.

Certain species and habitats are protected by UK and European Law; therefore, any potential impact needs to be mitigated in line with the exiting wildlife legislation and planning policies in place, be that national or local. Planning policies also detail the requirement for a net gain in biodiversity on proposed development sites.

What is included in a Phase 1 Habitat Survey Report? 

An Extended Phase 1 Habitat Survey or Preliminary Ecological Appraisal report includes:

  • Details of the methodology used and any limitations encountered;

  • Experience and credentials of those undertaking the appraisal;

  • Results and interpretation of the desk study;

  • Results of the Extended Phase 1 Habitat Survey site visit, including Phase 1 Habitat mapping;

  • Identification of the potential impacts on features of ecological importance and recommendations for avoidance, mitigation, or compensation, where appropriate;

  • Identification of the requirement for a further survey, where appropriate;

  • Recommended ecological enhancements; and

  • Details of relevant legislation and planning policy.

Stages of an Extended Phase 1 Habitat Survey

Desk Study

A desk study is undertaken to provide background data for the appraisal. Records of protected and notable species along with information on statutory and non-statutory designated sites within the vicinity of the survey site are requested from the local biological records centre. An online search is also undertaken to gather further background data on internationally and nationally designated sites within the local area.

Field Survey

Alongside the desk study, a Phase 1 Habitat Survey is undertaken which involves a site visit during which the ecologist completes a walkover of the site. During the walkover, plant species are recorded to enable classification and mapping of habitat types present within the site boundary. The ecologist will also assess the site for potential to support protected or notable species during the walkover and look for evidence of protected species (such as bats or newts) present within the site.

What is included in a Phase 1 Habitat Survey Report? 

All of the survey information is detailed within the Preliminary Ecological Appraisal report including survey methodology, results, potential impacts and recommendations. Recommendations are included within the report to reduce any impacts to ensure that legislation and planning policy is adhered to, where appropriate.

Preliminary Ecological Report process

Habitat mapping is undertaken using GIS software to provide geographical context to the Phase 1 Habitat Survey, aid assessment of the importance of the habitats on site and highlight features of particular ecological value.

The data from the desk study and site survey are used alongside professional judgement and experience to evaluate the likelihood of protected species being present, identify habitats of principle importance within the site and review designated sites within the zone of influence of the site to understand the potential impacts resulting from the proposed project.

The recommendations may include a further survey for protected species where evidence of, or potential for, a protected species has been identified within the site. The scope and timing of any further survey required will also be laid out to aid project planning.

When considering appropriate recommendations, the mitigation hierarchy is followed including avoidance where possible, minimising impact, restoring or offsetting. Throughout the process, client consultation is key to fully understand the scope and timeframe of the project.

In situations where the further survey is required to fully understand the ecological impact and identify appropriate mitigation a Preliminary Ecological Appraisal report is unsuitable for submission to inform planning applications. Data from the Preliminary Ecological Appraisal and the results of further survey are used to inform an Ecological Impact Assessment (EcIA) suitable for submission with planning applications. Where no further ecology survey is required, and the ecological impacts of the proposals can be confidently predicted, then the Preliminary Ecological Appraisal can inform an Ecological Impact Assessment suitable for a planning application.

Please note…

In situations where the further survey is required to fully understand the ecological impact and identify appropriate mitigation, a Preliminary Ecological Appraisal report is unsuitable for submission to inform planning applications.

Phase 1 Habitat Survey - Case Study & Example

Croxley Green

Ecology by Design was commissioned to undertake a Preliminary Ecological Appraisal of an area of land within a residential area to inform a planning application for the construction of residential dwellings. A site visit was completed alongside a desk study following which the habitats on site were assessed as being of relatively low ecological value. Sufficient data was available to fully assess the impacts of the proposals, which were considered to be of importance at a local level, and no further survey for protected species was required.

Preliminary Ecological Appraisal Report Example

Recommendations were made within the report for appropriate mitigation measures, in line with the mitigation hierarchy, including:

  • precautionary methods to be adopted with regard to vegetation clearance on site to avoid the destruction of active bird nests; and

  • design and implementation of a sensitive lighting scheme to avoid potential disturbance of foraging and commuting bats.

After consultation with the client, in accordance with planning policy, recommendations were also made for appropriate enhancements within the site, including:

  • bird and bat boxes;

  • hibernaculum; and

  • a planting scheme which would be of benefit to local wildlife.

For more information about Preliminary Ecological Appraisals, the steps involved and whether you or your company are in need of a consultation with one of our accredited ecologists, contact Ecology By Design today on 01865 893346 or contact us for more.