For free advice call 02380 261065


ECOSA carry out a range of surveys for all species of bat. These surveys typically consist of an initial assessment of trees and buildings for their suitability to support roosting bats, followed by further surveys to confirm the presence and status of roosts, and to identify key foraging and commuting habitat. Our team of bat specialists will help you achieve your development aims, whilst meeting all legal obligations and minimising disturbance of bats and their habitat.

All bat species, their breeding sites and resting places are fully protected by law - they are a European protected species. It is an offence to kill, capture or disturb bats, or to damage, destroy or obstruct access to roosts. Activities which are likely to affect bats include:

  • renovating, converting or demolishing a building;
  • cutting down or removing branches from a mature tree;
  • repairing or replacing a roof;
  • repointing brickwork;
  • insulating or converting a loft;
  • installing lighting in a roost, or outside if it lights up the entrance to the roost;
  • removing ‘commuting habitats’ like hedgerows, watercourses or woodland;
  • changing or removing bat foraging areas;
  • using insecticides; and
  • treating timber.

Bat surveys are subject to seasonal constraints. Should a bat roost be affected by development proposals a European Protected Species Mitigation (EPSM) licence will be required from Natural England before the development can proceed.

The licensing process can be complex with substantial lead times on decisions. It is therefore recommended that potential bat issues be investigated as early as possible to minimise project delays.

Licensed bat ecologists

Our ecologists are highly familiar with planning policy in respect of bats. Our project experience includes numerous bat roosting and activity surveys for proposed developments, including renewable energy projects, roads, housing developments, hospitals, schools and small-scale private home owner projects.

We can provide all bat survey and assessment services and reporting to support planning applications or conservation projects, from carrying out an initial Preliminary Ecological Appraisal to assess the suitability of your site to support roosting bats, through to more detailed bat roosting, activity and hibernation surveys, as well as tree climb and inspect surveys.

Bat surveys

Our bat survey methodology follows current best practice, including that outlined within the Bat Conservation Trust’s guidelines.

If a site is assessed as having suitable features to support roosting bats, or direct evidence of roosting bats is found, there is a requirement to carry out further surveys in order to confirm the presence/likely absence of roosting bats at the site, and if present, to assess the status of roosts.

Roosting bat surveys consist of dusk emergence and/or dawn re-entry surveys.

For example, a site assessed as having low suitability to support roosting bats requires a minimum of one bat survey.

Sites assessed as having high suitability to support roosting bats, or supporting a confirmed bat roost, require a minimum of three bat surveys.

CIEEM have published a useful guide for home owners on what to expect from a bat survey.

When can you survey for bats?

Bat roosting surveys can be carried out during May to September inclusive; the optimal survey period is between May to August inclusive.

Please refer to our survey timetable for further details regarding bat survey timings.

Securing a bat licence

Where impacts on roosting bats have been identified, we are highly experienced in preparing Natural England bat licence applications on behalf of our clients. Using the survey data collected during the bat survey works, we are able to devise appropriate and cost-effective mitigation strategies which are incorporated within the licence documentation.

Mitigation can range from installing bat boxes to the incorporation of bat roost features within new buildings or designing dedicated bat roosts, to site supervision during works and potentially post-development monitoring; mitigation strategies are dependent on the works to be carried out and the population and status of bat roosts involved.

In certain circumstances, we are also able to offer a faster route through the Natural England licensing process with the use of a Natural England Bat Mitigation Class Licence (BMCL). We have successfully obtained many licences for development works affecting bat roosts so that works can proceed.

For more information about licensing you can also refer to our handy guides; Natural England Licensing: An Overview and frequently asked questions

How much does a bat survey cost?

Bat survey costs are relative to the nature and scale of your project, and the suitability of a site to support roosting bats.

Please call 02380 261065 to discuss your project with one of our ecologists and we will give you clear guidance on what will be involved; or email

You can also request a quote for an initial assessment online.

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