Contact us

Preliminary Roost Assessment (PRA)

Assessment & reporting of bat roost potential on your proposed development site.

Preliminary Roost Assessments (PRAs) identify features that could support roosting bats in buildings and other structure, helping to inform key planning decisions. Get clear, detailed Phase 1 bat reports and guidance to understand next steps for your project.

Bat in hand
Hazel dormouse
Robin
Toad
Newt

In a nutshell

Seasonality: Anytime

Survey type: Desk study, field survey

Report lead time: 1 working day (from survey completion)

Report validity: 12-18 months

Bat in roof

What is a Preliminary Roost Assessment?

A Preliminary Roost Assessment (PRA), also known as a Preliminary Bat Roost Assessment or a Bat Scoping Survey, is the first stage in identifying whether buildings or other structures have the potential to support roosting bats. A suitably qualified ecologist will inspect the building, taking note of any potential roosting features (PRFs), such as lifted tiles, or signs of bat activity, such as droppings.

Bats are a protected species in the UK under the Conservation of Habitats and Species Regulations 2017 (as amended). A PRA will support planning and development decisions to ensure your proposed works are compliant and ecologically responsible.

Ecologist with gloves on holding a bat

When is a Preliminary Roost Assessment required?

Phase 1 bat surveys are often needed to support planning applications and help identify whether protected species may be at risk if proposed works go ahead.

PRAs are more commonly recommended for older buildings, rural sites and structures close to woodland, water or suitable bat foraging habitats. In many cases, they are recommended following a Preliminary Ecological Appraisal (PEA).

A PRA may be required if proposed development involves:

  • Roof repairs, alterations or re-roofing works
  • Demolition of buildings or structures
  • Barn conversions or agricultural building redevelopment
  • Extensions or loft conversions

When can a PRA be performed?

As PRAs focus on identifying features of roosting bats, rather than observing bat activity, they can be undertaken throughout the year, including in winter months.

Optimal Survey Season

Sub-Optimal Survey Season

Survey Not Possible

Jan

Bats: Preliminary Roost Assessment

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Our Preliminary Roost Assessment process

Our experienced ecologists carry out thorough, careful PRAs, which provide clarity on the potential presence of bats and recommended next steps. The process is as follows:

Phone

01

Contact & quote

Reach out to our team to receive clear guidance on your PRA requirements and the cost for your project. We’ll respond to all quote enquiries within 24 hours.

Clipboard

02

Desk study

The process begins with a review of the site and the surrounding area in ecological records, including nearby habitats and designated sites.

Document

03

Internal & external inspection

An appropriately experienced and licensed ecologist will inspect the building or structure for signs of roosting bats and features such as cracks, cavities, lifted tiles, gaps in timber framework and potential access points into roof spaces.

People

04

Reporting & recommendations

The survey concludes with a clear, planning-ready report outlining the findings, level of bat roost potential and whether further bat activity surveys or mitigation measures are likely to be required.

Phone

01

Contact & quote

Reach out to our team to receive clear guidance on your PRA requirements and the cost for your project. We’ll respond to all quote enquiries within 24 hours.

Clipboard

02

Desk study

The process begins with a review of the site and the surrounding area in ecological records, including nearby habitats and designated sites.

Document

03

Internal & external inspection

An appropriately experienced and licensed ecologist will inspect the building or structure for signs of roosting bats and features such as cracks, cavities, lifted tiles, gaps in timber framework and potential access points into roof spaces.

People

04

Reporting & recommendations

The survey concludes with a clear, planning-ready report outlining the findings, level of bat roost potential and whether further bat activity surveys or mitigation measures are likely to be required.

Project outcomes for Preliminary Roost Assessments

The findings of your Preliminary Roost Assessment will determine if further bat surveys or mitigation measures are needed as part of the planning process. Potential outcomes include:

Negligible Suitability: The building is assessed as having negligible suitability for roosting bats. No further bat surveys are typically required.

Low Suitability: Precautionary working methods or a single bat emergence survey may be advised, depending on planning requirements.

Moderate or High Suitability: Structures are considered suitable for roosting bats and further bat activity surveys are required during the active bat season.

Confirmed evidence of bats: If bats, droppings or other clear evidence of bat use are identified during the survey, the structure may be assessed as a confirmed bat roost. A small sample of any droppings will be taken for analysis to determine the bat species.

Why choose aLyne Ecology for your PRA?

At aLyne Ecology, we combine technical expertise with a friendly approach to deliver reliable, efficient Preliminary Roost Assessments.

Phone

Efficient delivery

Our organised in-house team can mobilise quickly, helping projects progress without unnecessary delays or uncertainty around requirements.

Clipboard

Licensed ecologists

Our bat surveys are carried out by ecologists with at least a Class I Bat Survey Licence, ensuring robust assessments aligned with best practice.

Document

Planning-ready reports

You’ll receive clear, thorough reporting which meets the requirements set out by CIEEM and BS 42020, supporting your planning application.

People

Friendly, expert team

We understand that ecological surveys and requirements can feel complex, so our team always operates in an approachable, helpful way.

Get a quote for your Preliminary Roost Assessment

A Preliminary Roost Assessment is often the first step in understanding whether bats could be affected by your proposed development works. Our experienced ecologists provide clear, practical advice to help you plan and understand the next steps.

We’d be happy to provide you with initial guidance and a quote for your Phase 1 bat survey, ensuring your project moves forward while meeting ecological requirements and responsibilities. Get in touch today to find out more.

Get a quote for your Preliminary Roost Assessment

A Preliminary Roost Assessment is often the first step in understanding whether bats could be affected by your proposed development works. Our experienced ecologists provide clear, practical advice to help you plan and understand the next steps.

We’d be happy to provide you with initial guidance and a quote for your Phase 1 bat survey, ensuring your project moves forward while meeting ecological requirements and responsibilities. Get in touch today to find out more.

Need something else?

Getting started with our ecological services couldn’t be easier. Start your journey today.

Contact details
Socials
Bat in hand
Hazel dormouse
Robin
Toad
Newt