Bat in Dover Castle


Overview & Legislation

Bats and their roosts are strictly protected by law. It is an offence to:

  • intentionally kill, injure, or take any species of bat.
  • intentionally or recklessly disturb bats.
  • intentionally or recklessly damage, destroy or obstruct access to bat roosts.

If you are planning works which may impact bats or their roosts, it is advisable to instruct a suitably licensed ecologist to carry out a Preliminary Roost Assessment (PRA) to determine the likelihood of roosting, foraging and commuting bats being present and impacted, and thus the need for further surveys and mitigation.

Bats may occupy crevices or open voids within buildings, structures and trees, and have changing roosting requirements at different times of the year. Different species also use the landscape and habitats in different ways for foraging and commuting purposes. For this reason, if, following the PRA, your ecologist advises you that bats may use your site and be impacted by the works, there are a variety of different survey types that may be recommended; the type of survey you will require will be dependent on your geographic location within the UK and the nature of the proposed works. The main types of survey you may require, include:

  • roost emergence / re-entry surveys;
  • activity surveys (for foraging and commuting bats);
  • swarming surveys; and
  • hibernation surveys.

Where a bat roost may be impacted or individual bats harmed, a European Protected Species Mitigation (EPSM) licence will be required from the appropriate statutory body before any works impacting bats or their roost can commence. Where planning permission is required in relation to the proposed works, the EPSM licence will only be issued once full planning permission has been granted and other wildlife conditions discharged. The results of the bat surveys will inform appropriate mitigation and enable us to complete the licence application and associated documents on your behalf. There are now different licensing options available through Natural England, which we can discuss with you to ensure that the most pragmatic and appropriate method is used for your development.

Note that any works to bat roosts or works that may harm individual bats that are not carried out under licence, or that deviate from the methodology detailed within the licence, are likely to be an offence under the Wildlife and Countryside Act, 1981 and Conservation of Habitats and Species (Amendment) (EU Exit) Regulations 2019. Penalties may take the form of unlimited fines and/or prison sentences of up to six months per offence.

Preliminary Roost Assessment (PRA)

The PRA is the standard baseline survey for bats whereby we carry out a ground level inspection of the buildings, structures and/or trees to be impacted by proposed works and assess their suitability to support roosting bats. Surveys of buildings and structures are usually carried out both externally and internally. Each building, structure and tree is then assigned as having high, moderate, low or negligible potential for roosting bats as defined by the latest industry guidance (Bat Conservation Trust, 2016).

We also assess the suitability of the wider site and surrounding habitats for foraging and commuting bats as per the latest industry guidelines (Bat Conservation Trust, 2016).

Where a bat roost is confirmed or potential for roosting, foraging or commuting bats is identified, and impacts to bats and/or a bat roost are likely, further surveys are likely to be necessary to inform appropriate mitigation.

Timings: The PRA can be carried out at any time of year, but where follow-on surveys are needed these are usually seasonally constrained. It is therefore advisable to instruct the PRA as early as possible in the design and development process.

Contact us now with any ecology queries: Claire Munn, Principal Ecologist: