Bat Surveys - whats involved?

As part of your planning application you may have been asked for a bat survey report. All species of bats in the UK and their resting places (roosts) are protected by law. Where a project or development is considered likely to affect bats or their roosts a survey and assessment of impacts will be required. Bat surveys can involve one or two stages.  The initial (phase 1) survey is a visual survey.  

Visual Survey

This survey can be undertaken at any time of year and the ecologist is looking for:

  • Signs that bats have or are using the buildings, structures or trees;
  • Features in buildings/structures and trees which could potentially provide a roosting place; and
  • The surrounding area’s suitability for bats.

In some cases the ecologist may be able to conclude at this stage that there is negligible potential for bats to utilise the structure affected by the development proposal, and that no further surveys are required.

If evidence of bats is found or if it is not possible to establish the presence/absence of bats via a visual survey alone (perhaps because all potential roost features cannot be visually searched) then bat emergence or re-entry surveys will be required.  

Bat emergence or re-entry surveys

These surveys can only be undertaken between May and September and at least one survey must be between May and August,  These surveys are undertaken either at dusk or dawn and record the numbers and species of bats and idenitfies bat access points within a structure.   

Bat mitigation statment

Upon completion of the surveys a mitigation statement will be prepared to accompany the planning application.  This statement will detail the mitigation measures to be employed to minimise/avoid impacts on bats.  This may include seasonal restrictions on when works can commence, ecological watching briefs for certain aspects of the works (e.g. roof removal) and provision of bat access points and roosting spaces. 


A European Protected Species (EPS) license may be obtained once planning approval has been granted.