What have bats got to do with my building project?

Most people would not quite make the jump from buildings to bats, in fact many of our clients are surprised when we mention the nocturnal little critters. The thing is, by not thinking about them you could end up with a hefty fine or, worst case scenario, a prison sentence! So get comfy, grab a note pad and find out exactly why you need to consider bats before you start your self build or renovation and, the actions you will need to take to make sure you don’t end up behind bars!

What makes bats so special?

The UK has 18 known species of bat and they are protected throughout Great Britain and Europe.  The UK Wildlife and Countryside Act 1981 (as amended) and EU Conservation of Habitats and Species Regulations 2010 lists protected bats among other fauna and flora.   It is, therefore, a criminal offence to harm or disturb bats or their habitat.   Natural England and The Bat Conservation Trust provide support, guidance and licensing towards their protection.

National and local planning policy include guidance towards the protection and enhancement of all biodiversity.   Town planners are required to consider any legally protected species as a material consideration when assessing development proposal that may harm a protected species or its habitat.

How do I know if there are bats present in my building?

Often our clients will say to us ‘we’ve never seen any bats – they aren’t using the building’ – the thing is, usually you can’t even tell. The Local Authority police this legislation through Planning Applications. The Local Authority Ecologist will look at the site and the surrounding area, using a list of criteria they will determine whether a presence survey will need to be undertaken prior to approval or even registration of the application. They use the following criteria to check for the likely presence of bats;

  • Hanging tiles
  • Timber cladding/weather boarding
  • Structures near woodland
  • Structures near water (streams/rivers/lakes/ponds)
  • Buildings with gable ends
  • Traditional clay tile roofs
  • Slate roofs
  • Any significant trees

Even if you are planning a new build, if the site has existing structures that you are planning to demolish, meeting any of the above criteria will mean that you will need a survey to report on the presence of bats.

Do I need to engage professionals to help me?

Professional ecologists can be employed to help develop design proposals for the built environment and are able to provide the necessary support for planning applications through survey and mitigation.

Proper assessment of existing buildings and other potential habitats for bats is crucial in design development prior to submitting your planning application.   For bats, initial assessment can take place at any time of the year.   A trained ecologist will look for key signs of bat habitation in a building, such as tile hanging, loose lead work and flashing (particularly around chimneys), small cracks & openings and not to mention bat droppings.   However, if bats are found to use existing buildings, further survey work is required to detect their emergence and activity in and around a building.   These emergence surveys can only take place when bats are out of hibernation and flying around; between May – September. This is why determining whether you have bats present or not early on is important.

Certain species of bats also live in trees and the cutting down of a tree could be causing harm to a bats habitat or the bat itself.   Whilst arboricultural work is not directly policed in regard to bat protection, seeking ecological advice before removing a tree may be prudent and considerate.

Can the presence of bats stop my building project?

The presence of bats within an existing building is by no means a show stopper to development.   With the right professional support of an ecologist the design can be taken forward coupled with appropriate mitigation, through the introduction of suitable bat habitation devices and details.   This information will be produced by the ecologist and submitted as a mitigation report with any planning application.   This mitigation report is also utilised to obtain a licence from Natural England enabling controlled works towards the completion of the proposed development with the protection of the bats in mind.

Early assessment will have significant benefits to a development project as it will enable the right ecology work to be carried out at the right time and it will allow the design to be taken in the right direction.

As architects we have a duty of care to advise our clients appropriately and to be aware of the basic principles in bat habitation potential.   With careful design and collaboration with a professional ecologist bat mitigation can be incorporated into beautiful design without being obvious.   The cladding on our Curvey Oak project has bat boxes and roosts designed into the elevation seamlessly … can you spot them?

Written by Verity Lovelock. Verity is an Architect at BBD Architects based in Hampshire. She is passionate about self build and renovation and, arming self builders with the knowledge to build the home of their dreams.

updated 05 March 2020