Planning Changes to Buildings with Bats

Bats must be considered from the outset of all building works, including maintenance. This section provides guidance for building owners and managers, their advisers, and others working on the site. 

Include wildlife in your plan

Bats may have roosted in an unmodified or unused building for decades. When renovation is planned, changes to the outside environment such as temporary buildings, security lights, car parks and paved areas can have an impact on bats too. The law and planning policy protect both bats and their roosting sites.

When buildings are no longer 'fit for purpose', they can, of course, still be habitats for the bats and other wildlife. When drawing up a feasibility study and planning changes or a new build, you should also plan for wildlife. The Bat Conservation Trust offers advice on creating roosting sites for bats.

When planning changes to buildings your options, in order of priority, are:

  • Avoid the loss of current roosts wherever possible. This minimises work that needs a bat mitigation licence, and has the greatest chance of successfully retaining bat populations on site.
  • If the loss of current roosts is unavoidable, plan to accommodate bats within the converted or new building. The new roost environment should have, as far as possible, the same or better conditions of temperature, humidity and roosting opportunities as the old roost. A new building is likely to need planning permission and obtaining this would be a prerequisite of a licence application.

Be aware that changes to a building used by bats may require a licence and you will need the advice of a bat specialist.

Project planning, management and monitoring responsibilities

Throughout any building maintenance or building project, you have responsibilities to consult a bat specialist consultant to evaluate the effect of any design, temporary works or building works on bats and their roost(s). You should also consult the local planning authority and Natural England at the earliest possible stage in the planning process and do so if there are subsequent alterations to the design, construction and handover phases of the works.

Each person who works on-site or who is involved in managing the work is responsible for safeguarding bats and their roosts, and wider bat habitats. You may wish to specify responsibilities in job descriptions for on-site personnel to ensure close liaison with the bat specialist consultant, and duties like checks that will need to be carried out. 

Team members may have had experience of working on bat-related building projects. There may be an opportunity to appoint a ‘biodiversity champion’ if staff with previous experience are keen to take on this role.

With the bat specialist consultant, the project team needs to plan how to integrate the bat surveys, and the licence requirements (where relevant) into the project programme and timing of works.

Project planning needs to ensure all the bat-related project costs have been identified and budgeted for. These could include:

  • Bat surveys
  • Bat monitoring after the building project is completed
  • Fitting out
  • Operation
  • Future maintenance
  • Interpretation about the bats and their roost may be useful and these costs need to be included too

Other project costs may need to be adjusted because of the timing of works.

When work begins, the pre-contract meeting and contractors' induction needs to cover general and site-specific information regarding bats and their roosts, and the importance of not disturbing them. This could include a ‘toolbox talk’ by the bat consultant. For example, actions such as closing doors and roof void openings to ensure bats are not disturbed or leaving accesses open so bats are not trapped would be guided by the project plan and bat specialist consultant.

The schedule of works and approved timeframe needs to be closely monitored by the bat specialist consultant to ensure compliance with the licence.

Towards the end of the work, you should ensure:

  • Maintenance contracts and regimes are in place before hand-over
  • Post-project evaluation and monitoring is undertaken by a bat consultant
  • Building users such as facilities managers are briefed and aware of their legal responsibilities towards the bats

Designing new or replica features for bats

Works on buildings may offer opportunities to integrate new or replica features for bats. You may also be required to compensate for lost bat habitat features. Your bat specialist consultant will be able to advise you on designing such features and suitable materials. The Bat Conservation Trust  also offers guidance on its web site, and their book ‘Designing for Biodiversity: a technical guide for new and existing buildings’ (2013) provides detailed advice on the design, construction and upgrading energy efficiency of buildings.

Case study – Somerset Wildlife Trust’s Keeper’s Cottage

The Mendip Hills and the Mells Valley are a very important area for the horseshoe bats, with one of the protected greater horseshoe bat roosts being very close to Harridge Woods, a Somerset Wildlife Trust nature reserve. The medieval and post-medieval coal mining remains in the wood are a scheduled monument.

With funding from the Lottery in 2006, the trust bought the ruinous Keeper’s Cottage on the edge of the wood. The cottage was already a bat roost but needed works to prevent further deterioration. A new loft was added, and the cellars were protected with a roof.

Seven species of bats now use the cottage throughout the year; greater horseshoe, lesser horseshoe, brown long-eared, Natterer’s, Daubenton's, pipistrelle, and the very rare barbastelle. A colony of Natterer’s bats also hibernate in the damp cave-like cellar in the winter.


Bat access points may easily be blocked by scaffolding poles, plastic sheeting or mesh. Seek advice from a bat specialist when designing and erecting scaffolding to ensure that bat access points are clear of obstacles and to avoid the offence of blocking a bat roost access point. This also applies to sheeting often used to protect a building or for containing spray during cleaning works.

Where sheeting or mesh is required, for example, for safety reasons near access points, it may be necessary to put it up and remove it daily for the duration of works in that area.

Bats have been known to get into scaffolding poles so special care needs to be taken when dismantling the scaffold.

Building site lighting

Building site lights in the roost or around the entrance may cause bats to desert the roost site, delay emergence or not emerge at all, which would be considered an offence under the legislation protecting them.