bat surveys and homebuilding

Planning Consent & Bat Surveys

Bats and building projects

The presence of bats can, and regularly does, hold up the planning process of a homebuilding project. Notorious for adding months of delay to a planning application, scheduling in time for a bat survey and subsequent rehoming of bats to achieve planning consent, will help minimise disruption and keep your building project on track. 

Bats are protected by law

There are 17 species of bats that breed in the UK and all are protected under European law. With bats in decline over recent years, mainly due to loss of habitat, this is particularly poignant in the South West, where the presence of bats is commonplace. The ancient woodlands and sweeping valleys around Bath provide the perfect environment for bats to thrive.  Great news for bats, less so for prospective home builders and developers in the Somerset, Wiltshire & Gloucestershire area.

Conservation of biodiversity

Local authorities are obliged to conserve the biodiversity of habitats as part of their local planning policy and every planning application will be assessed against the European Habitats Directive, before a planning decision can be made. Click here for BANES Bat Survey guidance.

Proposals to demolish empty buildings, convert attic spaces, even re-roof or build new can all have an impact on an existing bat habitat, so it is important to allow time and money up front to avoid any surprises.  Even if you are simply planning alterations to an existing building, it is important to follow the correct process to remain ‘within the law’.

When might a bat survey be required?

As a general rule, when planning building or alteration work, if any of the following circumstances apply, then anticipate the requirement of a bat survey from your local authority:

  • Converting empty buildings, especially agricultural buildings
  • Historic buildings with gable-ends or slate roofs, regardless of location
  • Dwellings and sites near woodland or rivers
  • Country locations away from street lighting
  • Conversion or renovation of empty roof spaces
  • Dry and undisturbed void areas below and around existing buildings
  • Buildings with small openings in walls and roof soffits

Evidence of bats

An explorative survey, carried out by a specialist bat ecologist, will confirm whether there is evidence of bats or the potential for bats to roost at your particular site. Should it be considered a ‘reasonable likelihood’ that bats are present or likely to be present, the local authority will require further validation as part of any planning application.

The bat survey window

There is a window of opportunity for follow up bat surveys. These need to take place between April & September, when bats are out of hibernation and active. Several visits by a bat specialist may be required and if you miss the bat season, planning permission could be delayed for 6 months or more.

Bat roosts

While many bats, such as the Greater Horseshoe bat, roost upside down in large open roof voids, many are crevice dwelling species. Pipistrelles and Serotines live in wall cavities, the gaps between roof tiles and in dark basement areas. Different bat species can have quite different roosting preferences and some are less resilient to change than others. While bats are believed to have existed for 50 million years or so, they are vulnerable to change and sensitive to the activities of humans. For this reason, their habits have been studied extensively resulting in UK and EU legislation to protect them.

Bat activity and building development

  • Bats live on insects which they catch in flight. They tend to follow rivers, hedgerows, interconnected areas of woodland where flying insects are abundant.

    · During the summer months when they are active – April to September they can lead semi nomadic lives moving between roosts covering a wide area over several days and sometimes weeks, sometimes stopping in a single location for just one night.

    · They are sensitive to light. Light spill from artificial lighting – street lights or through windows can affect their habits. Changes to existing patterns can effect established migration and feeding routes.

    · Domestic pets, particularly cats will kill bats. New homes in areas with a large existing bat population are likely to have a negative impact upon numbers.

    · whilst some people might be somewhat disturbed by the idea of having bats in their homes, many will unwittingly be already sharing living accommodation with them. If they are already in occupation, changes to the status quo need to be mitigated.

    · Bats hibernate during the winter months and as a result surveys for bats can only take place during April to September.

    · Destruction of an existing bat roost is a criminal offence and can carry a prison sentence. If one is discovered during building work, it would be necessary to stop immediately, whatever the consequences and obtain a license for further works.


Bats and planning consent

But do not think that if you have bats, they will put pay to your plans. In nearly every instance there will be an appropriate and acceptable mitigation measure that can be employed to protect the bats and allow you to build. Working a solution into your planning application will likely result in planning consent. You may need to install a bat box or create an alternative roost site and will require a special Bat Licence approved by Natural England. (Natural England bat licence information).

One of our best examples is at Withycombe, just south of Bath. The house had stood empty for 10 years, when purchased by our clients. Our proposal was for a radical transformation, making the most of those features worth keeping while changing and extending the house to make the most of the fantastic location. Crevice dwelling Serotine bats were found roosting between the slate in the roof space, which was to be removed altogether. Lesser Horseshoe bats were found in a void below the external terrace. Working closely with bat ecologists, new roosts were incorporated into the design and a mitigation strategy and licence granted for the work to take place. The project is nearly complete, with both bats and owners in residence.

serotine bats and horseshoe bats in Bath

Budgeting for bats

· For an explorative survey, allow around £1000

· For a follow up bat survey, budget around £2000

· For a bat licence allow £500 – £800

And please note, a bat survey is only valid for 12 months, so working your schedule around the bat season is important if you want to avoid delays in building work.

Designscape have a breadth of experience in designing homes for humans and bats! Again, timing is everything. Works affecting the roost will be linked to the bats seasonal activity, usually being undertaken during hibernation and Bat Licences can take several months for approval. It can useful to schedule this into the project plan. We work with some great ecologists and bat specialists and can help you navigate the process for a successful outcome.

Notorious for adding months of delay to a planning application, mitigating the presence of bats can help keep your building project on track.