Preliminary Ecological Appraisals

    Thomson EC’s specialists can help with all aspects of a Preliminary Ecological Appraisal (PEA)With over 15 years’ experience, we are well-placed to identify key issues and the scope of further work required to move forward with your development.

    All our surveyors are members of the Chartered Institute of Ecology and Environmental Management and meet the competency standards for PEA provided by this organisation.

    Arrange a preliminary ecological appraisal today

    What is a Preliminary Ecological Appraisal?

    A Preliminary Ecological Appraisal is normally, as the name suggests, the first stage in any site assessment.  PEAs are usually required during the planning process to enable a development to be approved. A PEA has two main elements: an ecological desk study and an extended Phase 1 habitat survey.

    The purpose of a PEA is to identify any ecological constraints to your development proposal. We will advise on what may additionally be required in order to complete the ecological assessment, for instance, protected species surveys. A PEA allows us to make recommendations where necessary for you to maintain compliance.

    When can they take place?

    A PEA should be undertaken as early as possible in the planning process. PEAs can be undertaken all year round, however, it is advised they should be conducted between April and September. If they occur outside this period,  there may be seasonal constraints and additional surveys may be required.

    About our Preliminary Ecological Appraisal Services

    Ecological desk study

    At Thomson, when undertaking the desk study, we collate data on statutory designated sites (legally protected), such as Sites of Special Scientific Interest, and priority habitats. We also contact the local biological records centre to obtain details of locally designated sites for wildlife and existing records of protected and priority species in the vicinity of the site. The data from these and other sources are brought together using GIS to provide either a printed map or an interactive map.

    Extended phase 1 habitat survey

    What our survey involves

    • Site visit to map habitats present
    • Record plant species present (and abundance)
    • Assess the potential of the site for protected and priority species
    • Record any evidence of protected and priority species
    • Advise on initial ecological issues highlighted and requirements
    • Guidance on measures to avoid and mitigate ecological impact

    Using the extended Phase 1 habitat survey technique (JNCC, 2010; IEA, 1995), we map the habitats present on the site and, if required, the surrounding area. For each habitat area, we record the plant species present and their abundance. We also assess the potential of the site for protected and priority species and record any evidence of these that we find during the survey, such as badger setts.

    As part of the PEA, we are able to advise on any initial ecological issues that we identify, for example, in relation to designated sites and priority habitats. We also advise on what is likely to be required in order to complete the ecological assessment, such as, surveys for protected species. Initial guidance on measures that could be incorporated into the development design to avoid and mitigate ecological impacts can also be provided at this stage. The PEA can, therefore, be an extremely useful tool for development master planning and can also form the basis of an Ecological Impact Assessment (EcIA) later in the project.


    Arrange a preliminary ecological appraisal with us today

    If you have any questions or would like to arrange a Preliminary Ecological Appraisal, speak to one of our specialists today.

    Contact us

    Biodiversity Net Gain

    Biodiversity Net Gain refers to a mandatory intervention which results in the net improvement to biodiversity for a defined area of land.

    Read more

    Ecological watching brief

    During development works, an ecologist may be required to guide operatives and oversee processes under an ecological watching brief.

    Read more

    Extended Phase 1 habitat survey

    The extended Phase 1 habitat survey provides a map of the habitats present on the site and a description of each habitat, including a plant species list.

    Read more

    Preliminary Ecological Appraisals

    A Preliminary Ecological Appraisal (PEA) has two main elements; an ecological desk study and an extended Phase 1 habitat survey.

    Read more

    BREEAM assessments

    We provide specialised ecological input for BREEAM and Code for Sustainable Homes (CfSH) assessments in line with current technical guidance manuals.

    Read more

    Habitats Regulations Assessment

    The Habitats Directive has been transposed into national law throughout the European Union.

    Read more

    eDNA testing

    A pioneering method used to evaluate the presence or absence of certain protected species on your site.

    Read more

    Ecology Survey Services

    We conduct all types of ecological surveys and assessments to support your planning applications.

    Read more

    Ecological mitigation

    When development works adversely impact protected species and their habitats, measures can be taken to mitigate damage.

    Read more

    Ecological Impact Assessment (EcIA) Services

    Our ecologists help our clients meet the principles of the avoid-mitigate-compensate hierarchy during the EcIA process.

    Read more

    Our Covid-19
    Business Response

    Find out more