Bat surveys are increasingly required by local planning authorities when building works requiring planning permission may affect roof spaces or other parts of buildings used by bats and this can include simple alterations to residential properties.
Bats and their roosts are protected under national and European law. Bats may roost in a wide range of structures both in rural and urban settings and the legislation makes no distinction between the size or type of development. Therefore local planning authorities are obliged to request bat surveys to accompany planning applications where there is a reasonable likelihood that bats are present, whether it is a commercial development or a householder application, e.g. for a loft conversion or extension.
The local planning authorities will expect a bat survey to be undertaken and a report to be prepared by a suitably qualified ecological consultant. Normally the local planning authorities will not validate the application until this has been done, because Government policy requires that all relevant information relating to protected species is provided before the application is determined.
There are two levels of survey that may be required for planning permission.
A preliminary bat survey
The preliminary bat survey can be carried out at any time of year and may consist of a background data search and will include a full building inspection to look for evidence of bat use and to assess whether the building has the potential to support bats.
Emergence activity surveys
Depending on the results of the preliminary bat survey emergence surveys may also be required; these can only be undertaken during the optimum period for bat activity, normally, May to August, but may be continued into September in suitable weather conditions. If activity surveys are required, it is important that they are carried out during the specified time period, regardless of the status of your planning permission. If they are undertaken outside of the optimum period the local planning authority may reject the information and the start of works may be delayed for a further year.
Simon Holmes holds a Class 2 Bat Licence (CLSO03440) and has 26 years experience of carrying out bat surveys and bat conservation work.