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.

Based in the World Heritage City of Bath, we regularly get enquiries from clients wishing to make alterations to a Listed building in order to make them meet the requirements of modern family living. From internal structural changes such as removing walls to open up the living space or converting the vaults to create additional living space to adding a large extension to allow reorganisation of the communal living spaces.

Listed Buildings Alteration

The way in which people occupy their homes today varies quite considerably from Georgian times. Most wish to live in a warm, dry house without damp, the past subdivision of a house into separate kitchen, dining and living room spaces is quite different to the open plan living we crave today and many wish to repurpose what would have been servants quarters into a home office or guest room to suite modern family living.

Listed Building Consent

Each of these seemingly simple building alterations require Listed Building Consent in order to transform a listed building into a modern family home and in some situations approval by the Local Authority Conservation team is resisted. Heritage England, the public body that helps people care for, enjoy and celebrate our beloved historic environment, has a useful guide to listed building consent here.

Historic England

It is a common misunderstanding that only the features included in the Listing Notice or the primary elevation are Listed. This is not the case. Be aware that it is a criminal offence to undertake works without the proper approval. Designscape have the in house expertise to help with this. Associate Alex Sykes can be found on the Riba’s list of Conservation Architects here.

Historic England give guidance on listed elements of a building as follows:

If an object is fixed to the principal building in such a way that it would be considered a fixture in the usual sense (it would be included in the sale details of a property unless expressly excluded), it would be protected by the listing.

This might even include that once fashionable avocado bathroom suite!

The good news is that once you make a Listed Building application, it is unlikely that work which took place in the C20th will be protected. However you must obtain approval to remove it. Work that affects the character of a Listed building will always require approval and will generally be resisted by the conservation team unless justified by diligent research and investigation. Interestingly, it is often much easier to justify a distinctly modern extension than obtain consent for a seemingly minor internal alteration to a Listed Building.


Historic Building Conservation

Many conservation officers have little truck with arguments such as: ‘But this is the kind of space required for modern family living!’ and are likely to respond with variations of: ‘This historic building has functioned as a house for 200 years, if you don’t like it move.’ This stance can seem pretty unreasonable, when you have spent a vast amount of money on your Listed property and want to deal with the water pouring through the basement vault, or want to knock two small rooms into one. There is no simple answer. Every day there are instances of unapproved work taking place within Listed Buildings in Bath, which can result in prosecution.  

Work with a Qualified Architect

The responsible approach to transforming a Listed Building into a modern family home, is to seek expert advice to guide you through the process of obtaining Listed building consent. But do bear in mind that you may need to modify your ambitions. As architects, we are creative problem solvers. We create beautiful spaces and buildings of quality and longevity. As professionals we are required to act with integrity and within the confines of statutory regulation and the law. Sometimes we need to give our clients advice that they do not want in order to protect them from their aspirations, but in all cases we are looking for solutions and ways in which we can obtain Listed Building planning consent for them.

Historic Homes transformed for Modern Living


While the alteration of a Listed building or historic homes rarely comes without its challenges by working with a skilled architect, you can successfully transform your properties into a modern, comfortable family home best suited to contemporary living.


Do get in touch for an informal chat or book a free consultation here.  We look forward to talking to you.

Based in the World Heritage City of Bath, where there are more than 5000 Listed Buildings, we regularly get enquiries from clients wishing to make alterations to their Listed property to help meet the requirements of modern family living