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What is an Ecological Survey?

What is an ecological survey?

An ecological survey is the process whereby a proposed development site is assessed to establish any environmental impact the development may have. With any potential new land development, along with cost estimates, insurance, structural warranty, and planning permission, you will need to conduct various site surveys, including an ecological survey.

A new development may be:

  • A personal residential build

  • A new commercial site

  • An addition to an existing development

A ecological site survey will assess all areas of your site, and and will likely encompass any considerations, issues or problems that will need to be addressed from an ecological standpoint.

An ecology survey considers the site’s immediate environmental impact on existing habitats, and will help developers established the necessary next steps to ensure the development can continue.

Developers will also need to consider environmental legislation, to ensure they are abiding by the law throughout development and land planning.

Helpful resources

Ecological survey calendar [Downloadable PDF]

Do I need an ecology survey?

You will need an ecology survey on any site where there is a possibility of an existing ecosystem or habitat for protected species.  Below are some typical examples of habitats of protected species. If any of the below can be found on the proposed development site, you will need to conduct an ecological survey. 

  • Heathland

  • Lakes or bodies of water 

  • Ponds or ditches 

  • Woodland, scrub, or hedgerow

  • Parkland, pasture or meadow

  • Complex tree structures, caves, or cave-like spaces

  • Coastal habitats 

  • Large rural or suburban gardens

  • Existing derelict buildings, farm buildings, timber frame buildings with access points

Regardless of whether evidence of protected species habitat is found or not, it will be necessary to conduct an ecological survey early on in the development planning.

How to conduct an ecological survey

By understanding how to best go about an ecology survey, you can plan in advance and allow for any potential setbacks of your build, meaning that your timeline, schedule, and budget is affected as minimally as possible.

Why is an ecology survey important?

An ecological survey is important as:

  • Developers/applicants will be aware of any ecological constraints early on

  • Development plans can factor in plans to minimise impact on biodiversity

  • BAP (Biodiversity Action Plan) species will be identified so that there is minimal  r no disturbance to their habitat

  • It ensures the design of the mitigation is appropriate to the site

What is a biodiversity action plan?

A biodiversity action plan, or BAP, is a program that is internationally recognised that works to address issues relating to threatened species and habitats. The BAP is designed to protect and restore existing biological systems and you can find a list of BAP species here.

This can then be considered within the wider plans for BNG, or Biodiversity Net Gain, which recently became a pressing concern and was mandated to a certain percentage to avoid a vastly detrimental environmental impact.

What are the stages of an ecology survey?

There are two main stages of an ecology survey:

Stage 1: Preliminary Ecological Appraisal

The first survey carried out is often called a Preliminary Ecological Appraisal (PEA) or a Phase 1 Habitat Survey. This is a ‘rapid’ survey and involves an initial desktop study and a walkover survey.

Features of a Preliminary Ecological Appraisal

  • A ‘rapid’ survey

  • Involves an initial desktop study

  • Involves a walkover survey

What will the study identify?

This study will identify any ecological constraints that exist on your site, and will also discover any potential opportunities for introducing new habitats. This initial appraisal will also build into the future plans any necessary surveys that are necessary. This will be dependent on what specific habitats are discovered (such as bat, badger, bird, or otter for example).

What are priority habitats and species?

In 2013 the UK Biodiversity Action Plan was replaced by ‘UK post 2010 Biodiversity Framework’ this identifies those species that are most threatened and require action. The framework is designed to protect and restore existing biological systems and you can find a list of habitats and species here.

This can then be considered within the wider plans for BNG, or Biodiversity Net Gain, which recently became a pressing concern and was mandated through the Environment Bill to secure a 10% biodiversity net gain through development work to avoid a vastly detrimental environmental impact.

Government mandate on increasing Biodiversity

The importance of ecology surveys is more important than ever before, due to a new mandate that requires the Biodiversity Net Gain of any new development to be at of least a 10 percent increase. Within the most recent Environment Bill, binding environmental targets have been set in place, as highlighted in this article.

What happens next?

If nothing is found…

If no problems or issues are raised within the first appraisal, then no further survey work is needed, and the report can be submitted for planning. However, if further work is needed, i.e., something is found, such as evidence of a protected species, then this needs to be discussed before any further action is taken.

Don’t forget:

The ecology survey needs to be carried out long before planning permission is granted, as, if something is found, then ecologists will have to agree an approach to mitigate for any impact to the habitats or species and may need to consult with the local planning authority before anything else.

If you are in need of a specialist ecology team to carry out an ecology survey, contact us today and see how we can help you and start the process.

What does the initial survey achieve?

  • The initial Phase 1 ecological survey identifies the potential presence or absence of habitats and species, and also the degree to which they’ll be affected. The mapping of the site identifies any records of species within a 2 km radius.

  • This helps the project proposer and local planning authority scope the subsequent ECIA or Ecological Impact Assessment (more of that to come later).

  • As well as determining whether any work is needed to be carried out, the preliminary survey also concludes if there are no ecological issues that cause concern. This is just as important as this determines whether the application can be validated and planning permission processed.

Essentially, either way, an ecological survey is needed.

What is involved in a Preliminary Ecological Appraisal?

Desk Study

A desk study is undertaken by an ecology consultancy to provide background data for the appraisal. The desk study involves initial research to gather background data on the area to establish any records of protected or notable species. Research is also done to determine any internationally or nationally designated protected sites in the local area. 

Field Study

The field study will include an assessment of:

  • Habitat type

  • Species composition

  • Management

  • Vegetation structure

  • Age/permeance of site

Alongside the desk study, an extended Phase 1 Habitat Survey is undertaken which involves a site visit, during which the ecology consultant completes a walkover of the site. During the walkover, plant species are also recorded to enable the classification and mapping of habitat types within the site boundary. The habitat survey is extended to assess the site for protected or notable species. Ecologists will look for evidence of or potential species such as reptiles and bats. 

You can read more about Ecology by Design's work here.

Stage 2: Ecological Impact Assessment

An ecological impact assessment will be needed if any evidence of a protected species is found.

What is an ecological impact assessment?

An ecological impact assessment is the second stage of an ecology survey. Often referred to as an EcIA, this assessment will include a detailed ecological report. This report is an essential document that describes the potential effects of development on the existing habitats or species that have been found. The assessment examines the results of the preliminary ecological appraisal and takes the necessary steps based on the data findings. This will usually detail how any development could impact a specific species or habitat that was originally found in the preliminary ecological appraisal. An ecology consultant will undertake a detailed species or habitat-specific survey. The ecology report is presented by ecological consultants and can be presented alongside a planning permission application.


There are several steps to an EcIA, including:

  • Scoping and data gathering

  • PEA (Preliminary Ecological Appraisal)

  • Detailed protected species surveys

  • Evaluation of site’s nature conservation value/habitats, species it contains

  • Impact assessments that interpret the survey data to identify habitat loss, magnitude and significance

  • Mitigation

  • Residual impacts

  • Creating a report that gives stakeholders all the relevant information they could possibly need about the ecological impact of the development

If you’re unsure of the best way forward with your development plan, you can contact us to speak to an ecology consultant. Otherwise, give us a ring on 01865 893346 or email us at hello@ecologybydesign.co.uk for more about how we can help you.

Who requests ecological impact assessment?

  • Construction companies

  • Developers who want to undertake residential construction or regeneration projects. (This could encompass retail, leisure developments, wind farms, roads or pipelines.)

Every ecology survey is different, just like every individual project or development idea is unique.

Why do I need an ecological impact assessment?

An ecological impact assessment is necessary in order to continue with development on a site. Failure to provide one may mean development cannot go ahead.  If evidence of a protected species is found, data must be gathered to ascertain the impact any proposed project will have. Without clear reports on the habitat and how development will impact it, planners will be unable to devise clear mitigation strategies for the proposed development project to continue.

A key part of an EcIA is outlining how a project will adhere to relevant legislation and planning policy including any measures which should be implemented to enable this. In doing this, consideration is given to the key principles of avoidance, mitigation and compensation, known as the mitigation hierarchy.

Every new development has a responsibility to minimise the impact on the environment and surrounding habitats, and where possible, offset any impact by creating new habitats within the site. This is referred to as your Biodiversity Net Gain which plays an essential part in planning for any new development. 



What is included in an ecological impact assessment?

There are several steps to completing an ecological impact assessment, including scoping, reporting and licencing. The steps are as follows:

Step 1. Initial Scoping and data gathering 

The first step in completing an ecological assessment is to complete a Preliminary Ecological Appraisal (PEA), incorporating a Phase 1 habitat survey and a desk study. The PEA identifies the habitats present on-site and the potential for any protected species, as mentioned earlier. If nothing is found then no further surveys are needed. 

Step 2. Further surveys (if required) and value assessment 

To understand the value of the site additional detailed surveys are often required. These are known as Phase 2 surveys. They can include botanical surveys, as well as surveys for bats, great crested newts, hazel dormice, reptiles, water voles, badgers and breeding birds. Site visits and assessments determine the presence of a species, with observation taking place over a matter of days, weeks or months depending on the exact species. 

Should further surveys be required then, depending on the time of year, they could start immediately. However, there are strict windows of time during which each survey can be undertaken. We recommend you familiarise yourself with the ecology survey calendar to see when the optimal periods for surveys are. 

Step 3. Impact Assessment 

Once all surveys are complete the likely impacts on protected habitats and species can be assessed. This is informed by the nature of the proposed development, including masterplans, landscape plans, drainage and lighting proposals, among other aspects. 

Step 4. Mitigation, compensation and enhancement 

Where potential impacts are identified, measures to avoid, mitigate or compensate for those impacts will be recommended. These should be developed in consultation with the client and project team, to ensure they are deliverable under the proposals.

This stage of the project often needs to be considered alongside other assessments such as the Land Use and Ecology section of BREEAM or Biodiversity Impact Assessment calculations to demonstrate how the proposals will deliver a net gain for biodiversity.

Step 5. Ecological impact assessment ecology report 

Once all surveys are complete, the results, interpretation, assessment and mitigation/compensation are presented in a single detailed EcIA report, supported by detailed plans as required. This ecological impact assessment report is prepared for submission to inform the planning application. As part of an EcIA, ecologists will liaise with the client, local planning authority, and Natural England, where appropriate, to ensure the potential impacts of the proposed project are fully understood and all features of ecological importance which may be impacted are identified. The assessment process involves the identification of ‘important’ ecological features, the potential impacts of the project, and ‘significant effects’ on important ecological features.

Step 6. Licensing 

Where European protected species are impacted, works will only be able to proceed under licence, usually obtained from Natural England. Any mitigation or compensation measures for impacts on these species ultimately need to be approved by the local planning authority (for planning permission) and the licensing authority (for works to proceed) e.g. Natural England in England.

How long do ecological impact assessments take? 

Lead time for ecological impact assessments, and therefore ecology surveys, varies on several important factors. This is because some survey types are seasonally constrained, and often ecologists work with unpredictable deadlines, as is the nature of projects and developments. Developers and project managers, therefore, should ideally plan for ecological constraints early on in development. Occasionally, ecological reports or ecological surveys will need to be carried out by law.

All the findings from the Ecological Impact Assessment are presented in a detailed report written by the ecological consultancy.  

What is included in an ecology report?

This ecology report will present the following: 

  • A detailed background into the study 

  • Details of personnel who conducted the assessment 

  • Methods of desk study, surveying and assessment 

  • The results of the surveys and any findings 

  • An interpretation of the findings

  • An assessment of potential impacts of the designated site proposals on habitats and species 

  • Measures for mitigation strategies, including avoidance, compensation and enhancement measures 

  • Details for how these measures will be adopted to ensure species and habitats are protected 

  • Details for how these measures will enhance the natural environment 

The EcIA report may need to be supported by calculations to present biodiversity losses and gains within the site via a Biodiversity Metric. 

Get in touch with us if you need an ecology report from a licenced ecological consultancy.

How much does an ecology survey cost?

An ecology survey can cost anything from £750 - £4000. The overall costs of an ecological survey depend on several factors, the main being whether any species are found during the initial survey. You can read more about the exact costs of an ecological survey in our detailed guide: Costs of an Ecological Impact Assessment.

When is the best time to conduct an ecology survey?

The best time to conduct an ecology survey is dependant on the specific potential habitats on site. Download our Ecological survey calendar [Downloadable PDF] for helpful information on the best time to carry out an ecological survey. 

How long do ecology surveys take?

The amount of time an ecology survey takes will depend on whether any species are found. If species are found, then further ecology surveys will need to be conducted, and depending on the type of species found, the lead time for these surveys will vary. This is why it is important to conduct an ecology survey as early as possible in the planning stages of new development.

Factors affecting the length of an ecology survey:

  • The type of survey being undertaken 

  • How many surveys are required to comply with current legislation 

  • The time of year, and whether a waiting period is necessary until optimal survey time 

  • The size of the development itself 

How long are ecology surveys valid for? 

The validity of surveys is determined by how long the specific data is valid. Most surveys are valid for a time between 12 months and 2 years. After this point, you may have to re-survey the area, as circumstances and habitats may have changed within this time frame. 

Validity of ecology survey data

The validity of survey data is as follows:

  • Survey data less than 12 months old 

Data from surveys is likely valid in most cases. 

  • Survey data between 12 months - 18 months old 

Most survey data is considered valid after this amount of time unless there has been a specific change in circumstance. 

  • Survey data between 18 months - three years old 

Most survey data collected will become redundant after three years. For data that falls within this bracket, you will need to check whether it is still valid. You may need to carry out another survey to refresh the data collected to ensure it is up to date and relevant. 


If there have been any notable changes in and around the site since the survey was carried out, such as the emergence of a mobile species, then a survey will need to be carried out again.  If a project takes longer than originally proposed, this could affect the validity of the survey data. Additionally, if any ecological conditions change during the development time, then additional surveys may be required to factor these in. 

What happens if I don't carry out an ecology survey? 

If you don’t carry out an acology for a proposed development, it can lead to the following:

Legal proceedings 

Failing to carry out an ecology survey can be punishable by law, should a project be undertaken that disrupts, interferes or destroys the habitat of a protected species. 

Costly setbacks during a project build 

If you fail to carry out an ecology survey within a suitable time frame, the setbacks could cost a project significantly. It can cause timely setbacks and costly ones, too, potentially impacting the project lead time and overall completion. 

Irreversible damage to an existing ecosystem 

Starting construction without an ecological report from an ecology consultancy could see an existing habitat damaged beyond repair, and an entire ecosystem affected with irreversible consequences. Not only could this lead to legal proceedings, but it can also cause issues with stakeholders and reputation, should the legal formalities not be followed with any project build or development plan. 

What surveys are required for planning permission?

A Phase 1 Habitat Survey will be required to confirm the absence or presence of protected species on site. Should protected species be found, an Ecological Impact Assessment will also be needed in order for a project or development to continue. 

If you’re unsure of the best way forward with your development plan, speak to our team of ecological consultants today.

Ecology survey and report example

If we conduct a PEA of a farmyard complex in July, and identify evidence of or potential for roosting bats, we can conduct surveys immediately to inform the potential impacts of the proposals.

Outcome: This would mean all surveys could be completed within three months of instruction.

However, if an on-site pond with suitability for great crested newts (GCN) was also identified in July, we would not be able to undertake surveys until the following spring. We could conduct a habitat suitability index (HSI) assessment and a rapid risk assessment to confirm the likelihood of committing an offence under the proposals.

Outcome: There may be a delay in the planning application.  However, in some parts of the country GCN surveys can be forgone in favour of the District Licencing approach.

Once all surveys are complete, the results, interpretation, assessment, and mitigation/compensation are presented in a single detailed report, supported by detailed plans as required. It normally takes around two weeks to turn around an EcIA report, although this only takes around two days of reporting, mapping and quality control time therefore can be fast-tracked where required.


Is an ecological impact assessment the same as an environmental impact assessment?

No. An Environmental Impact Assessment (EIA) is a separate process that is only required when a project is likely to have a significant effect on the environment. Screening thresholds triggering the need for the impact study are set out in The Town and Country Planning (Environmental Impact Assessment) Regulations 2017 (often referred to as the ‘EIA regulations’). These details when an environmental assessment is required.

Projects we typically get involved in that trigger the need for an EIA assessment include:

  • Industrial estate development projects (exceeding 0.5 hectares (ha));

  • Quarries;

  • Urban development projects (> 1ha not including dwellings; >150 dwellings or overall development exceeds 5 ha);

  • Waste disposal or waste treatment plants;

  • Motorway service areas (>0.5 ha);

  • Construction of roads (>1 ha);

  • Holiday villages and hotel complexes outside urban areas (>0.5 ha) or permanent campsites (>1 ha); and

  • Installations for hydroelectric energy production (>0.5 megawatts) or wind farms.

An EIA report is presented as an Environmental Statement (ES). This will be produced by a multidisciplinary team and considers a wide range of environmental effects including, for example, water, air and soil pollution, noise, vibration and light, as well as ecology.

Developers can ask their local council for a formal ‘screening opinion’ which will confirm whether their project is an EIA development. Where an EIA is necessary, developers can also ask the council for a ‘scoping opinion’ which specifies the issues that must be included in the assessment as part of the EIA process.

What is ecological mitigation and why it is important?

Ecological mitigation is a vital element of today’s processes, specifically relating to how you best tackle any issues that are raised with the initial survey. You should consistently be aiming for the appropriate amount of BNG, particularly as a 10 percent increase recently became law.

For example, this article highlights how the UK's rail network is planning to lessen the impact on biodiversity through an action plan to increase biodiversity.

Don’t forget…

A mitigation scheme will need to be submitted long before your planning application and can take up to 40 days to be processed, and it is for this reason why one of the first things you should do when you have access to your site is an ecology survey.

Essentially, with an ecology survey, you can iron out any issues that may come to fruition later on in the build. By determining these before they become problems that are both costly for your time, resources and budget, you can set in motion how you will resolve the issue with the help of experts such as Ecology by Design.

What is a mitigation scheme?

A mitigation scheme is essentially a strategy to reduce adverse effects on the environment. This could be something such as:

  • Capture and relocation of protected species or habitats

  • Pollution interceptors to minimise pollution of watercourses

  • Screens to reduce visual disturbance to birds

  • Tunnels under roads to allow wildlife to pass from two sides of the road (a natural corridor)

  • Strategies to reduce noise and air pollution for the species in the area

Mitigation services from Ecology by Design include:

  • Great Crested Newt Mitigation

  • Water Vole Mitigation

  • Ecological Mitigation

  • Bat Mitigation

  • Water Vole Mitigation

  • Ecology Mitigation

  • Onsite Mitigation

Why should you plan a mitigation Scheme early?

A mitigation plan is beneficial to both the development and the community. Every construction project that has the potential to disrupt wildlife and the habitats specific to them will require careful analysis.

A survey reveals a series of proven ways to ensure your development does not destroy, disturb or negatively affect the immediate environment.

Ecology by Design Mitigation Services

The mitigation services offered by Ecology by Design can be specified to each specific case. You can turn to the experts at Ecology by Design should you need any of the following:

Pond mitigation

A pond mitigation might include a pond redesign, pond construction or pond enhancement, in order to impact the pre-existing wildlife as little as possible. Some species that particularly can be affected by new developments within pond conditions are great crested newts, for example. You can read more about great crested newt surveys here.

Species mitigation

Species mitigation, in particular, refers to how you will allow the existing species to thrive within new conditions that suit both the habitual needs of the species and the development plans themselves. Some of the services provided by Ecology by Design include:

  • Badger setts

  • Bat roosts

  • Bird boxes

  • Otter holds

  • Newt habitats

  • Log piles for habitation

  • Water vole displacement or translocation

We will liaise with regulatory bodies to ensure all projects undertaken fit within the planning permission of the areas and will ensure all parties are on the same page throughout the project.

Rare plants translocation

The relocating of plant species can ensure that there is minimal impact of a species within your development if this applies to your specific situation. The relocating or a rare plant species or entire habitat is referred to as a rare plants translocation and is just one of the mitigation services we can provide.

Within a rare plants relocation, we will also shift multiple hectares of grassland, hedges, trees, and wetland vegetation, should the survey suggest this a necessary step.

Wetland mitigation

Wetland mitigation refers to any ecological work carried out involving river re-alignment, design, and construction.

With wetland mitigation from Ecology by Design, you can also expect all necessary communication with local authorities to be undertaken by us, as experts within the field who can provide all the relevant and essential data of the survey. Liaison with regulatory bodies would be vital for some aspects of wetland mitigation, including fish removals.

How developers can benefit from ecology surveys

A development cannot hope to continue or start a project without an initial survey. In fact, the impact on local habitat, wildlife, and the general environment will need to be considered long before building takes place. It is best to consider a development’s environmental impact within the first stages of planning, in order to encompass and design an area within the build that compensates for the impact you will have.

Animal Surveys

Ecology by Design can conduct protected species survey services, ranging from simple scoping surveys to detailed impact assessments.

The animal surveys that can be conducted by Ecology by Design include:

Click here to discover our range of protected species surveys.

Botanical Surveys

Along with an ecology survey, something you may want to consider is a botanical survey.

For any botanical survey, similarly to a species survey, a habitat survey will be carried out. This will provide a map of habitats present on-site including:

  • A list of individual plant species

  • Target notes of important features of the site

The Phase 2 may include a national vegetation classification, that will essentially identify and map vegetation using defined plant community types.


When should I conduct a botanical survey?

The best time to conduct a botanical survey is between April and October, as the winter months make it difficult for ecologists to assess the site to the extent necessary for a thorough survey.

A botanical survey will require considerable botanical expertise and can only be undertaken by suitably experienced botanists.


BREEAM Assessments (Building Research Establishment Environmental Assessment Method)

Another factor to consider if you are considering an ecology survey is BREEAM assessments. BREEAM assessments require an ecologist to produce a calculation of the change in the ecological value of a site, as well as determine how to enhance the site’s value.

Ecology by Design can provide SQE’s (Suitably Qualified Ecologists) to advise clients, and will work with your architect to devise a suitable scheme.

Within the BREEAM survey, you will also find recommendations for protecting the ecological features on-site. There will also be an assessment of the long-term impact on biodiversity such as a management plan for the development.


Why conduct a BREEAM survey?

  • Helps to manage and mitigate risk

  • Helps to lower costs & maximise returns

  • Demonstrates sustainability performance during planning, design, construction & operation

As a leading independent ecology consultancy, Ecology by Design can help you with every stage of your survey. With an experienced team of ecologists on hand to help with years of experience, we can ensure your development plans can encompass any necessary changes so you can set in motion any necessary action plans to increase biodiversity.


No matter where you are based in the UK, or the size of the project, Ecology by Design can help. Contact us today for more information about our range of services.