Ecology, biodiversity net gain, and open space consultancy for local authorities and developers across the UK.

Protected species surveys

Bat surveys

Bats are a vital part of the UK’s biodiversity, using a variety of habitats including woodlands, buildings, bridges, and mature trees for roosting and foraging.

All UK bat species and their roosts are protected by law under the Wildlife and Countryside Act 1981 (as amended) and the Conservation of Habitats and Species Regulations 2017. It is illegal to disturb, capture, injure or kill a bat, or to damage, destroy, or obstruct access to their roosts.

Ecology that works on the ground

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Reducing risk in the planning process

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Balancing ecology with project delivery

Direct access to experienced ecologists

Real-world land management expertise

Supporting sustainable communities

Trusted by Local Planning Authorities

Pragmatic solutions, proportional advice

Helping avoid planning delays

Surveys to BNG units - all in one place

When are bat surveys needed?

Surveys are commonly needed for:

Renovation, demolition, or conversion of buildings, barns, and bridges.

Tree works, felling or surgery of trees with features suitable for roosting bats.

Construction projects in areas with high bat activity or suitable foraging and commuting habitats.

Major infrastructure projects such as new roads, pipelines, or energy developments.

Bat roosting upside down in cave habitat

Survey process

Depending on the habitats present on site, one or all of the following surveys may be required to inform a planning application.

When is it required?

Bat activity surveys are required when development proposals may affect habitats that are important for bat flight paths, foraging, or social behaviours..

Purpose

Bat activity surveys are designed to provide a detailed, representative picture of how bats use a site. They aim to answer key questions, including:

Species

Which bat species are using the site?

Activity

What are the levels of activity or abundance onsite?

Habits

How are bats using different habitats within the site?

Area

How do onsite habitats connect to surrounding areas for bats?

We use two main approaches when it comes to bat activity surveys

Bat activity surveys are split into the following approaches:

Manual Transect Surveys

Conducted by experienced ecologists using bat detectors, these surveys follow set routes (transects) through the site at dusk, recording bat activity and identifying species in real time.
Typically carried out once per season—spring, summer, and autumn—to capture seasonal variations.

Automated/Static Activity Surveys

Bat detectors are deployed at fixed locations around the site to continuously record bat calls over several nights. The data is then analysed to determine bat presence, species composition, and activity patterns.
Usually conducted each month between April and October, or less frequently for sites with low suitability.

Outcomes

Informed decisions

The results from bat activity surveys inform the development design process, helping to avoid or reduce impacts on bats and their habitats.

Assessment

Findings are assessed and incorporated into an Ecological Impact Assessment (EcIA), which evaluates how the proposed development may affect bats.

Guide mitigation measures

This information is a crucial part of the planning decision-making process and may be used to guide mitigation measures, such as habitat retention, lighting design, or the creation of new bat foraging and commuting routes.

When is it required?

Bat activity surveys are required when development proposals may affect habitats that are important for bat flight paths, foraging, or social behaviours..

Purpose

Bat activity surveys are designed to provide a detailed, representative picture of how bats use a site. They aim to answer key questions, including:

Process: Preliminary Survey (Year-Round)

A detailed visual inspection of both external and internal features to assess roosting potential. We use tools like endoscopes and thermal imaging cameras for thorough analysis.

Outcomes

 The building is classified into one of four categories: Negligible, Low, Moderate, or High potential for roosting bats.

Negligible Potential 

No further surveys required.

Low, Moderate, or High Potential 

Further emergence will be necessary.

When is it required?

For buildings with Low, Moderate, or High potential for roosting bats where planned works could impact a possible roost.

Purpose

To determine if bats are using the building, including the species, type of roost, and other details needed for a bat licence application.

Process

Advanced Survey (May–August)

Conducted at dusk or dawn using specialised recording equipment to identify bat species.

Number of Surveys

Up to three surveys may be required, depending on the building’s potential. For complex structures, we also use thermal imaging cameras.

Outcomes

No Bats Recorded

 A detailed report is provided to the local authority, and no bat licence is required, although precautionary mitigation measures may be recommended.

Bats Recorded

The building is confirmed as a bat roost. A comprehensive report will detail species, roost type, development impacts, and necessary mitigation, compensation, or enhancement measures. Our approach is always proportional—avoiding unnecessary recommendations like dedicated bat lofts unless essential.

Licence Requirement

 If impacts cannot be avoided, a European Protected Species Licence will be needed after planning permission is obtained. Ethos can manage the bat licence application for you.

When is it required?

A bat licence is mandatory when a bat roost will be destroyed, damaged, altered, or obstructed by development proposals—whether in a building, tree, or cave.

Purpose

To provide legal permission for impacting or destroying a bat roost, ensuring compliance and avoiding fines or legal repercussions.To determine if bats are using the building, including the species, type of roost, and other details needed for a bat licence application.

Process

Timing

A licence can only be applied for once planning permission is secured. Natural England’s approval can take several months, so a minimum lead time of four months is recommended.

Expertise Required

A licensed bat worker must complete the application. Ethos has extensive experience in securing complex licences and designing innovative compensatory bat roosts.

Low Impact Bat Licence Option

We also offer the Low Impact Bat Licence, a more cost-effective and efficient alternative when conditions are suitable. This option streamlines the legal process, providing security for roost destruction with fewer restrictions on work timings.

Why developers choose Ethos?

A wealth of knowledge

..surrounding quanitative bat surveys and compliance.

Experienced surveyors

Our team includes highly experienced, skilled surveyors. 

Proven track record

Extensive experience conducting bat surveys across a variety of habitats, ensuring compliance with legislation and planning policies.

Proportionate approach

We deliver tailored solutions that balance ecological requirements with development objectives and always consider the most practical solution.  
Ecologists inspecting badger sett entrance during field survey

Timely reporting

We provide clear, comprehensive reports to support planning applications. 
Walled garden with orchard trees and managed green space landscape

Rapid site visit availability

Ensuring minimal delays to development timelines preventing costly delays.

Receive a detailed breakdown
for your project

We provide tailored solutions to help you deliver high-quality, sustainable green spaces. Contact us today to discuss your needs. Whether you require:
Biodiversity net gain
Policy advice
Full strategy
Ecological assessments.

01225 444114

info@ethosep.co.uk