Standing advice for planning consultations - Bats

This is standing advice to help planning applicants seeking permission for development that could affect bats, and to assist planning officers and other regulators in their assessment of these applications. It avoids the need for us to advise on individual planning consultations in relation to bats. We will only provide further advice in exceptional circumstances that are not covered by this standing advice.

Consideration of protected species in development management

Scottish Planning Policy requires that the presence (or potential presence) of legally protected species is factored into the planning and design of development proposals, and that any impacts on protected species are fully considered prior to the determination of planning applications.

Where impacts on a protected species cannot be avoided, certain activities may only be undertaken with a licence from NatureScot. It is important that any licensing issues are considered as part of a planning application to avoid any unnecessary delay to a development proceeding.

Legal protection for bats

There is no change to the protection of European Protected Species (EPS) as a result of EU Exit. 

All species of bats occurring in Scotland are classed as European Protected Species (EPS) under the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended). There is no change to the protection of European protected species as a result of EU Exit. It is therefore an offence to deliberately or recklessly:

• kill, injure, capture or harass a bat;
• disturb a bat whilst it is using any structure or place for shelter or protection (roost sites), or in any way that impairs its ability to survive or breed, or significantly affects the local distribution or abundance of the species;
• obstruct access to a roost site, or otherwise deny its use by bats.

And whether or not deliberate or reckless:

• to damage or destroy a bat roost, irrespective of whether bats are present.

This means that if bats could be affected in these ways by a development, and no action is taken to prevent it, an offence may be committed. The advice below will help ensure that impacts on bats are minimised and no offences occur.

When a development could affect bats

Shetland is the only part of Scotland where bats are not resident, and so do not require any consideration. Bats are known to occur locally on Orkney and many Hebridean islands (including Lewis & Harris), so their presence cannot be ruled out in these island groups even where there are no recent records. For the latest distribution maps see the National Biodiversity Network Atlas. The NBN Atlas maps indicate the broad pattern of distributions across Scotland but cannot provide detailed information for individual development sites. Local Record Centres may have additional information that can help determine if bats are likely to occur on a site. See also the Atlas of the Mammals of Great Britain & Northern Ireland (The Mammal Society/Pelagic Publishing 2020).

Bats commonly roost in undisturbed spaces in buildings and in crevices and hollows of trees. They also use crevices in bridges and underground sites such as caves, mines, tunnels and ice-houses. Roost sites can be in both urban and rural situations. They can therefore be affected by a wide range of development types and locations where trees, caves or man-made structures need to be modified or removed, or where construction activity may disturb a roost (eg. noise, lights and, human presence).

A bat roost survey should be carried out if a proposal could affect bats in these ways. A list of triggers for bat surveys is provided in Bat Surveys for Professional Ecologists: Good Practice Guidelines 4th edition (Bat Conservation Trust 2023).

Wind farms can pose an additional risk to bats due to the potential for bats to be killed or injured by colliding with the moving turbine blades, and/or due to internal damage caused by sudden reductions in air pressure close to moving blades (barotrauma). Wind farm proposals may require a bat activity survey to assess this risk and the potential impact on bat populations. For more details see Bats and Onshore Wind Turbines: Survey, Assessment and Mitigation. The guidance does not cover small scale domestic turbines, for which the following advice specifically refers:

Free-standing domestic turbines

Consideration needs to be given to bat commuting routes and other habitat features where bat activity is focused. Evidence from scientific studies indicates that turbines can:

• lead to displacement of bat activity within a zone of 20m from the turbine and this effect may negatively impact on the bats if the displacement is from important habitat features; and
• attract bat activity in some circumstances and that siting turbines close to features of particular interest to bats, is therefore best avoided.

Free-standing domestic turbines should therefore not be located within 20m of buildings, watercourses/open fresh water (especially with tree-lined banks/margins), hedges, forest edges or lines of trees.

Roof-mounted turbines

Proposals involving roof-mounted turbines should require a bat survey of the building concerned in order to inform the precise siting of the turbine. Such turbines should never be located anywhere near known bat roost exit/entry points. In practice, given that these access points may not remain constant over time, combined with the possibility of attraction (as above), this may mean that the turbine should not be mounted on the building, but should be free-standing at least 20m away.

Carrying out a bat survey

Surveys should be done by persons with the appropriate knowledge of bat ecology and practical experience of bat survey work, and in accordance with Bat Surveys for Professional Ecologists: Good Practice Guidelines 4th edition (Bat Conservation Trust 2023). Timing of roost surveys is complicated by the fact that bats use different roost sites at different times of the year; for shelter, breeding and mating during the main active period between April and October, and for hibernating over the winter between November and March. Bat activity surveys for assessing the risk of wind farm collisions should be done between April and October, following the methods described in Bats and Onshore Wind Turbines: Survey, Assessment and Mitigation.

The level of bat survey needed will depend on the nature and scale of a development proposal, and should be proportionate to the degree of risk to bats. Deciding on the level of survey requires the judgement of an experienced ecologist. Where surveys require the close inspection of known roost sites, and bats could be disturbed, surveyors will require a survey licence from NatureScot to avoid committing an offence (contact [email protected]). A survey licence isn’t required for examining potential roost sites with no known history of use by bats, but if an unlicensed surveyor discovers bats, or their signs, and any necessary further examination may result in the disturbance of bats, then they should withdraw immediately and apply for a licence to continue with the survey.

The survey information needs to be sufficiently up-to-date when a planning application is submitted. Pre-application bat surveys normally remain valid for two more survey periods, and should be repeated if the application is going to be delayed beyond the start of a third survey period. Unless it is clearly evident that there has been no substantive change in number, distribution or activity of bats since the original survey was undertaken.

Reporting survey results

If a development proposal has needed a bat survey, a survey report must be submitted as part of the planning application. The report should include:

• names, experience and licence number of surveyors;
• details of any information gathered from Local Record Centres or other sources;
• descriptions of habitat surveyed and any limitations to the survey, such as access to roof voids and visibility when undertaking roost exit/re-entry counts;
• survey methods, including survey area, date, time, weather conditions, and mapping the location of surveyors in relation to structures during surveys;
• details of any acoustic detection equipment used;
• a map showing location of roosts and entry/exit points, and other key areas of bat activity such as commuting routes and foraging areas, in relation to development;
• the status of each roost (maternity, hibernation etc.), an estimate of the number of bats of each species in each roost and an assessment of the overall importance of the development site for bats;
• an assessment of how the development might affect bats.

Details of the bat activity information to report as part of a wind farm collision risk assessment are provided in Bats and Onshore Wind Turbines: Survey, Assessment and Mitigation. The presentation of the bat activity data should follow the standardised format described in this guidance and be entered into an online tool (Ecobat) to gain a measure of the level of bat activity relative to other locations in the region.

If bats could be affected by the proposal, the report must include a protection plan. The plan should include:

• measures proposed to minimise impacts on bats, including annotated maps and/or photographs showing the location of any measures proposed and how they relate to survey information and construction work;
• a summary of any residual impacts once the above measures are taken into account;
• details of any licensing requirements.

Measures to minimise impacts on bats

Measures to minimise impacts on bats should follow a hierarchy of avoidance, mitigation and compensation:

Avoidance

• Design the development and construction methods to avoid damage or disturbance to bat roost sites, and allow their continued use; and to minimise any loss or fragmentation of foraging and commuting habitat.
• Schedule works to avoid the period when a roost is in use and might be disturbed.

Mitigation

• Temporarily exclude bats from a roost while works take place.
• Minimise new lighting around roosts, foraging or commuting corridors.

Compensation

• Provide alternative roost sites as appropriate, if the destruction or permanent exclusion of existing roost sites is unavoidable - for maternity roosts this should be like for like compensation.
• Restore or improve habitat to replace lost habitat or habitat connectivity.

Details of these measures and their implementation are provided in the CIEEM UK Bat Mitigation Guidelines 2023. Measures to retain the original roost location and access are always preferable to more intrusive approaches such as exclusion and the provision of alternative roost sites. The destruction of a roost, or exclusion (temporary or permanent) of bats from a roost, will require a licence from NatureScot. Works carried out under licence will need to be timed carefully so as to avoid any direct harm to bats.

Avoidance and mitigation measures to minimise the collision risk to bats from a wind farm proposal include:

• siting turbines to avoid areas of high bat activity;
• 50m buffers between turbine blade tips and habitat features used by bats for foraging ie. woodland edge, hedgerows and watercourses;
• reducing the rotation speed of blades when turbines are idling
• slowing down the rotation of turbine blades (feathering) during periods of high bat activity.

See Bats and Onshore Wind Turbines: Survey, Assessment and Mitigation for details of when these measures are appropriate and their implementation.

For all development proposals where bats are a consideration, pre-construction surveys should be timetabled into project plans. This is to enable checks for any roosts that may have become occupied after the original survey, and to ensure the measures proposed to minimise impacts on bats remain appropriate. Pre-construction surveys should be completed as close to the start of works as possible, and always within the most recent survey period.  

Licensing development works affecting bats

Licences for development works that would otherwise result in an offence with respect to EPS, such as bats, can only be issued if it can be demonstrated that the following three tests are all met:

Test 1 - that the purpose of the licence is to preserve public health or public safety or for other imperative reasons of overriding public interest, including those of a social or economic nature and beneficial consequences of primary importance for the environment.

Test 2 - that there is no satisfactory alternative.

Test 3 – that the proposed action will not be detrimental to the maintenance of the population of the species at a favourable conservation status in their natural range.

There is a presumption against licensing the destruction or exclusion of maternity bat roost sites while they are being used. Any licensed works in these circumstances would have to wait until the roosts are unoccupied; normally between 1 October and 31 March.

For advice on applying Tests 1 and 2 see NatureScot guidance European Protected Species Licensing Test 1 – Licensable Purpose and European Protected Species Licensing Test 2 – No satisfactory alternative. For advice on applying Test 3 and whether or not a licence is likely to be granted, planning applicants and planning officers may contact the NatureScot licensing team.  An up-to-date bat survey and a bat protection plan for the proposed development must be submitted with the enquiry, together with details of the development proposals. We would normally only expect these enquires to be for rarer bat species, and/or exceptional roosts in terms of location (edge of range) or size.

A licence is likely to be granted for low impact works meeting the above tests and where all the following points apply:

• planning permission has been granted for the development/works in question;
• works will only affect soprano pipistrelle or common pipistrelle bat roosts that are not used for breeding or hibernacula;
• bat surveys have been carried out by a licensed ecologist in accordance with the best practice outlined above, and within the last 18 months;
• a bat protection plan has been prepared by a licensed ecologist in accordance with the best practice outlined above.

For development works affecting low numbers of non-breeding soprano and common pipistrelle bats, we have adopted a bat low impact licensing approach (BLIMP). This is a more streamlined approach that enables experienced ecologists to permit low impact works without having to apply for individual licenses in each case. For more information see our guidance BLIMP Licence – When and how it should be used, an ecologist’s guide.

Our website provides guidance on applying for a bat licence for development purposes, along with the application form. For further information on protected species licensing see Protected Species Licensing: Legislation, Appropriate Authorities and Licensing Purposes.

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