Ecologial Appraisal and Assessent – Frequently Asked Questions

When preparing development proposals understanding ecological constraints is essential. Here we answer some of the most frequently asked questions about ecological appraisal and assessment, helping you navigate planning requirements and environmental responsibilities with confidence.

What is an ecological appraisal?

An ecological appraisal is an assessment of a site to identify the presence of habitats and species, assess potential constraints, and determine whether further surveys are required.

The most common starting point is a Preliminary Ecological Appraisal (PEA). Sometimes referred to as a “survey or preliminary ecological appraisal”, this initial assessment involves:

• A desk study reviewing existing ecological records
• A site walkover survey
• Identification of potential ecological issues
• Recommendations for further surveys (if required)

Why do I need an ecological appraisal for my planning application?

Most local planning authority policies require ecological information to accompany a planning application particularly where development may affect:

• Protected or priority species
• Priority habitats
• Trees, grassland, wetlands, or watercourses
• Designated sites (such as SSSIs or Local Wildlife Sites)

Without adequate ecological information, your application may be delayed or refused. Early ecological input helps identify risks and ensures compliance with planning policy and wildlife legislation.

What are designated sites?

Designated sites are areas protected for their ecological importance. They may include:

• Sites of Special Scientific Interest (SSSIs)
• Special Protection Areas (SPAs)
• Special Areas of Conservation (SACs)
• Local Nature Reserves
• Local Wildlife Sites

If your site lies within or near designated sites, the potential impacts of your development will need careful consideration, often through more detailed assessment.

What happens during a Preliminary Ecological Appraisal (PEA)?

A PEA typically includes:

• A review of ecological data within a specified radius
• Assessment of on-site habitats
• Identification of evidence of protected or notable species
• Evaluation of habitat suitability
• Recommendations for furthers surveys

An ecologist from our team will determine whether there are species present and whether additional activity surveys are required – for example, for bats, great crested newts, reptiles, or breeding birds.

What are priority habitats and priority species?

Priority habitats and priority species are those identified as being of principal importance for biodiversity conservation.

Examples of priority habitats include:

• Lowland meadows
• Ancient woodland
• Coastal saltmarsh
• Hedgerows

Examples of priority species include:

• Bat species
• Breeding birds
• Great crested newts
• Hedgehogs

If these are identified on or near your sites, mitigation or enhancement measures will likely be required.

Why does the time of year matter for ecological surveys?

The time of year is critical because many species are only detectable during specific seasons. For example:

• Bat surveys for activity: May to September
• Great crested newt surveys: March to June
• Breeding bird surveys: March to August
• Reptile surveys: April to September

Undertaking surveys at the incorrect time can lead to inconclusive results, requiring repeat visits the following season – potentially causing significant delays.

What are ecological impact assessments (EcIAs)?

Where development proposals are larger or potentially more complex, an ecological impact assessment may be required.

These surveys:

• Assess the significance of ecological features
• Evaluate potential impacts of development
• Propose mitigation, compensation, and enhancement measures
• Demonstrate compliance with biodiversity net gain requirements

An EcIA is more detailed than a PEA and is often required for larger sites or where sensitive habitats and species are present. An EcIA also demonstrates compliance with emerging planning requirements, including biodiversity net gain, showing that the development will leave biodiversity in a better state than before. 

What is biodiversity net gain?

Biodiversity net gain (BNG) requires developments to deliver measurable improvements to biodiversity compared to the pre-development baseline.

Your ecological assessment will:

• Calculate habitat units
• Identify losses and gains
• Recommend habitat creation or enhancement

BNG is now a mandatory consideration for many planning applications and must be addressed within your ecological and environmental documentation.

Can ecological constraints stop my development?

In most cases, ecological constraints do not prevent development entirely. Instead, they influence:

• Site layout
• Timing of works
• Mitigation strategies
• Long-term habitat management

Early ecological input allows issues to be resolved through sensitive design and phased implementation.

How long does the ecological appraisal process take?

Timeframes depend on:

• Site size and complexity
• Whether protected species are suspected
• Seasonal survey requirements
• The local planning authority’s validation requirements

A simple PEA may take a few weeks. However, if multiple activity surveys are required across appropriate seasonal windows, the process may extend over several months.

What should I do before submitting a planning application?

Before submitting a planning application, you should:

• Commission a survey or preliminary ecological appraisal
• Confirm survey timing aligns with seasonal constraints
• Review likely potential impacts
• Incorporate mitigation into your design
• Ensure reports meet local planning authority policy

Proactive ecological planning reduces delays and improves approval prospects.

Why is early ecological advice important?

Engaging ecological consultants early:

• Identifies risks before design is finalised
• Avoids costly redesign
• Ensures compliance with wildlife legislation
• Supports smoother planning determination

By addressing ecological and environmental considerations at the outset, developers can demonstrate responsible stewardship and meet regulatory requirements efficiently.

How can Collington Winter assist?

At Collington Winter, we assist developers, landowners and planning professionals in managing ecological and environmental requirements to support successful development proposals. The team undertakes preliminary ecological appraisals and more detailed surveys to identify habitats and species.

We understand the importance of working closely with clients to provide a great service and deliver excellent results. We aim to provide a service which meets the needs of developers, whilst ensuring positive outcomes for wildlife.

If you would like to find out more about ecology surveys, contact us today using the form below. You can also contact our team via email at info@collingtonwinter.co.uk.