Preliminary ecological appraisal
A preliminary ecological appraisal (also known as an Extended Phase I Habitat Survey) is an ecological assessment method which evaluates the existing ecological value of a site and identifies any ecological constraints to a proposed development. Surveys are undertaken by qualified and experienced ecologists and typically consist of three elements:
- An evaluation of the ecological value of the study area based on a desktop review that summarises information collated on notable habitats, notable and protected species records and nature conservation designations in the area.
- An assessment of the study area’s habitat composition and floristic abundance derived during a walkover survey.
- A protected species assessment that evaluates the likelihood of protected species and invasive species occurring within the study area.
A preliminary ecological assessment can be undertaken as part of an Ecological Impact Assessment or as a standalone assessment.
 Study area
A study area is determined for each stage of the assessment. The study area will vary for both the desk study phase and the field survey stage. The desk study phase will usually consider a wider area between 1/2km and 10km from the development site. The field survey will encompass the development site and typically up to 50m around the site boundary.
- For designated sites of nature conservation interest, websites such as the Multi-Agency Geographic Information for the Countryside, Joint Nature Conservation Committee, Countryside Council for Wales, Scottish Natural Heritage and Northern Ireland Environment Agency.
- Locally designated sites and notable or protected species or habitats records from local environmental record centres.
- A search for waterbodies using the Ordnance Survey website and aerial photography.
 Field survey
During the field survey, ecologists will use the Phase I Habitat Survey methodology (Joint Nature Conservation Committee, 2010) and the ‘Guidelines for Baseline Ecological Assessment (Institute of Environmental Assessment, 1995).
The distribution of habitats present within the study area will be mapped and for each habitat area, the key plant species will be recorded. The potential for the site to support notable and protected species will also be assessed, along with any evidence found during the surveys, such as badger setts. Typically, the potential for the following notable and protected species are assessed:
- Nesting birds.
- Water voles.
- Great crested newts.
Invasive plant species will also be searched for and recorded during the field survey.
Any constraints to the field survey such as restricted access into specific areas or dense vegetation preventing thorough assessments will also be recorded.
A detailed report is produced on completion of the desk study and field survey. This will summarise the findings of both stages. It will identify any constraints to the proposed works and provide recommendations for any further surveys that may be required. This could include more detailed surveys for protected or notable species or more detailed botanical surveys. Recommendations for ecological enhancements may also be included.
An ecological survey may be required in advance of a planning application being submitted if the proposed development could impact on biodiversity. It is advisable to undertake pre-application discussions with the local planning authority to determine if any surveys are required. All public authorities have a duty under the Natural Environment and Rural Communities Act 2006 to have regard for conserving biodiversity. The National Planning Policy Framework (NPPF) also places an emphasis on avoiding a net loss of biodiversity and achieving net gains for nature.
 Related articles on Designing Buildings Wiki.
- Biodiversity in the urban environment.
- Biodiversity offsetting.
- Ecological impact assessment.
- Ecological survey
- Eco-Management and Audit Scheme.
- Environmental Impact Assessment.
- Environmental policy.
- Environmental plan.
- Great crested newt.
- Planning permission.
- Protected species.
- Protected species licence.
- Site survey.
- Tree preservation order.
 External references
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