Bat Survey

A Bat Survey is ordinarily triggered when there is to be:

  • Conversion, modification, demolition or removal of buildings (including hotels, schools, hospitals, churches, commercial and derelict buildings) which are:
  • Agricultural buildings (e.g. farmhouses, barns and outbuildings) of traditional brick or stone construction and/or with exposed wooden beams
  • Buildings with weather boarding and/or hanging tiles that are within 200m of woodland and/or water
  • Pre-1960 detached buildings and structures within 200m of woodland and/or water
  • Pre 1914 buildings within 400m of woodland and/or water
  • Pre 1914 buildings with gable ends or slate roofs, regardless of location
  • Located within, or immediately adjacent to woodland and/or immediately adjacent to water
  • Dutch barns or livestock buildings with a single skin roof and board-and-gap or Yorkshire boarding if, following a preliminary roost assessment, the site appears to be particularly suited to bats.
  • At the behest of the LPA / County Ecologist.


Ordinarily, the form of initial survey required is a 'scoping survey' designed to investigate the presence of bats and / or the potential presence of bats. This is often in association with a survey for nesting birds.


The outcome of the scoping survey dictates the next course of action: 

  • No / Negligible Potential - Usually indicates the end of the matter, (although, the LPA ecologist could still insist on further survey work).
  • Low Potential - A minimum of one emergence survey
  • Moderate Potential - A minimum of two emergence surveys
  • High Potential / Confirmed Roost - Usually three emergence surveys are required.

Emergence Surveys

These can only be undertaken between May and August inclusive and on ocassion extend into September. If you think you might require a survey, do not delay, book today or you might be waiting longer than you think or wish.


Emergence surveys are intended to prove that the building is or is not a bat roost. If bats are recorded, the survey records the access / exit point used by the bats, the numbers and species present. A decision is then taken on how to proceed. This could mean a Mitigation - Method Statement or an Natural England European Protected species Licence (EPSL). The exact requirements are dealt with on a case by case basis.


Activity Surveys


Activity surveys are often required where development is to take place in a previousy undeveloped area such as agricultural fields or brown field site which has reverted back to a more natural state.


Each site is individually rated as either:

  • Low Habitat Value

 – One Survey Visit Per Season (April – May / June – August / September – October) +

                    Five nights automated recording per season

  • Moderate Habitat Value

 – One Survey Visit Per Month (April – October) +

                   Five nights automated recording per month

  • High Habitat Value

​ – Two Survey Visits Per Month (April – October) +

                  Two automated recorders (ten nights) per month


The objective of the survey is to ascertain what if any bat species frequent the area and thus devise an appropriate mitigation scheme to ensure that bats using the site, are not impacted by the proposals.


Survey effort is normally conducted in accordance with Bat Conservation Trust (BCT) guidelines or upon the guidance of the LPA Ecologist.


Any queries or concerns?

Ecological Surveys Ltd

Providing a comprehensive suite of Ecological Surveys on the Isle of Wight -

Click here to see the range of Protected Species (Phase II) Surveys

Contact us today!

If you have any queries or wish to discuss your project, please contact us:

Telephone:0800 888 6846

Mobile: 07736 458609


Email: paul@ecologicalsurveys



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