Services · Core

Preliminary Ecological Appraisal

The starting point for most ecological planning projects. A PEA combines a desk study with a site walkover survey to identify existing habitats, highlight potential protected species constraints, and determine any further ecological surveys required to support a planning application.

Survey seasonYear-round

Report turnaround1 month

Also known asExtended Phase 1 Habitat Survey

Overview

A Preliminary Ecological Appraisal (PEA) is a standard ecological survey required for most planning applications in England and Wales. It identifies habitats present on site, assesses the likelihood of protected species, and determines whether further ecological surveys are needed to support planning permission.

A PEA combines a desk study and an extended Phase 1 habitat survey. The desk study reviews biological records, aerial imagery, designated sites and planning history within an appropriate search area. The Phase 1 survey is a site walkover carried out by a qualified ecologist, recording habitat types, boundary features, buildings, waterbodies and any signs of protected or notable species.

The final report provides a Phase 1 habitat map, identifies ecological constraints and sets out clear recommendations for planning. In many cases, a PEA is sufficient to support a planning application. Where additional surveys are required, such as bat surveys, great crested newt eDNA or reptile surveys, the report confirms what is needed, when surveys should be undertaken and why they are required.

When you need this

You are submitting a planning application where ecological information is required at validation
You are demolishing, converting or extending buildings that may support bats or nesting birds
You are developing land with habitats such as scrub, grassland, woodland, hedgerows or waterbodies
You are changing the use of agricultural or brownfield land where habitats may be present
You are removing or managing trees, particularly mature trees with potential bat roost features
The site is within or near a designated nature conservation area (e.g. RAMSAR, SAC, SPA, SSSI, NNR, LNR, LWS)
You need to demonstrate biodiversity net gain (BNG) for planning approval
The ecological baseline is unknown or insufficient for validation
You are preparing an outline application or responding to LPA pre-application advice

Our approach

01
Desk study
We review biological records, designated site information, aerial imagery and planning history to establish the ecological context of your site and its surroundings.
02
Extended Phase 1 walkover
A qualified ecologist undertakes a site survey to classify habitats, map ecological features and assess potential for protected species. Buildings, trees and waterbodies are individually evaluated.
03
Mapping
We produce clear, detailed maps showing the site location, nearby designated sites, identified habitats and ecological target notes recorded during the survey.
04
Reporting
We produce a clear, planning-ready report with habitat maps, ecological considerations and recommendations for any further surveys, including indicative timelines. All reports follow CIEEM guidelines.

Survey season

January–December

Optimal: April–September

PEAs can be carried out at any time of year, so you do not need to wait for a specific survey window to progress your project. The optimal period is April to September, when vegetation is in full growth and habitats are easiest to identify. Surveys undertaken in winter are still fully valid for planning purposes. While some botanical detail may be less visible, habitat classification and protected species potential can still be assessed, and any seasonal follow-up surveys can be scheduled at the appropriate time if required.

Regulatory context

National Planning Policy Framework (NPPF)Paragraph 180 requires planning decisions to protect and enhance biodiversity. Local Planning Authorities (LPAs) commonly require ecological assessments to validate planning applications where ecological impacts may be possible.
Biodiversity Net Gain (BNG)Most planning applications are now required to demonstrate a measurable net gain in biodiversity. A PEA provides the baseline ecological information needed to support BNG assessments.
Wildlife and Countryside Act 1981This legislation protects wild birds, bats, reptiles and other species. A PEA identifies potential presence of protected species and any legal constraints on development.
CIEEM GuidelinesWe follow the Chartered Institute of Ecology and Environmental Management (CIEEM) guidelines for Preliminary Ecological Appraisals, ensuring surveys and reports are carried out in line with best practice.

Related services

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Frequently asked questions

01Can a PEA be done in winter?+

Yes. PEAs can be undertaken year-round. While a winter survey may miss some botanical indicators, it will still accurately classify habitats and assess potential for protected species. Where seasonal follow-up surveys are required, the PEA will identify the appropriate survey type and the earliest suitable survey window.

02Is a PEA the same as a Phase 1 habitat survey?+

They are closely related but not the same. A Phase 1 habitat survey focuses on mapping and classifying habitat types. A PEA includes this work but also assesses potential for protected species and provides recommendations for any further surveys required. Most Local Planning Authorities now expect a PEA rather than a standalone Phase 1 habitat survey.

03Will my planning application be rejected without a PEA?+

Most Local Planning Authorities will not validate a planning application where there is potential for ecological impact unless an appropriate ecological assessment has been submitted. Submitting without a PEA can result in delays, requests for further information, or refusal to validate the application until the required ecological information is provided.

04What area does the desk study cover?+

Typically, a 2 km radius is used for both designated sites and protected species records. This may vary depending on the site and the species involved.

Get in touch

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