Everything developers need to know about Bat Surveys in 2021
What is a Bat Survey? On this page, you can find all the information you’re ever likely to need to know about bat surveys and what happens next. And if for some reason you don’t, our friendly bat consultants are available to answer your questions. A great place to start learning is the video below by Robert Oates, Managing Director of Arbtech.
Questions like “what happens to my planning application if I have bats?” are asked of our team on a daily basis by people just like you, all across the UK.
We know that bats might not have been in your game plan and the original costings for your project, so we do appreciate you’re a little worried about what comes next. Fortunately, our team have never failed to secure a planning consent for a client where bats have been found or are even suspected to be present at a site.
Of course, there’s a protocol to follow; assessments to be done, reports to be submitted to your local planning authority, and in some rare cases, protected species licences to be obtained… but that’s all in a day’s work for us here at Arbtech.
With a huge team of fully licensed ecologists all over the country, we have among the broadest and deepest bat expertise of any ecological consultancy in the country. If you’re submitting a planning application in 2021, then this page is everything you need to know.
First, some background – what is it that defines a bat roost?
In the UK, we have 17 different bat species that breed here and they are all protected by law. Bats live in places referred to as roosts. When we talk about a roost, we are referring to the “feeding or resting place” of a bat.
A bat roost can be found in a number of different places including; caves, cracks in trees, lofts, and barns and even under loose, hanging tiles on the exterior of properties. Bats like to set up their roosts where there is a safe place to hibernate, raise their babies and find insects and water to feed on.
The type of bat–crevice or void dwelling–will generally dictate the type of roosting features e.g. on the exterior or a building that bats will use to roost.
Bats also have different requirements for their roosts at different times of the year, so they will often move around to find a roost that suits them and occupy multiple sites throughout the year.
There are day roosts, transitionary roosts, feeding roosts, maternity roosts, and many more besides. Each of these will be spatially different and provide the bats with a place of security from predators, while being relatively stable in terms of their exposure to changes in temperature, humidity, wind, noise and light.
When can bat surveys be done?
There are two types of bat survey. Let’s call them ‘Scoping’ and ‘Emergence,’ for the sake of simplicity. A scoping bat survey (stage 1), is an internal and external inspection of your buildings and can be undertaken at any time of the year. The exercise is designed to report to you and exclude the presence of three triggers for emergence surveys, as follows:
- presence of bats i.e. positive/negative
- evidence of their activity e.g. droppings, urine stains, bits of prey, dead bat carcasses
- access to features suitable for roosting; graded on a continuum from negligible through to high
If bats are present or evidence of bats is found, or there is medium to high potential for roosting – such as hanging tiles, gaps in walls, unsealed properties or infrastructure close to woodland – you will have to propose mitigation or habitat enhancements for bats in your planning application.
Without this mitigation, there would be a net loss of habitat—the cause of bat population decline that drove lawmakers to legally protect bats and their roosts in the first place.
Obviously, it is not possible to propose bat mitigation for the loss of roosting habitat if e.g. the species of bat, the population numbers, and the roost’s significance is unknown.
To illustrate this point: it is much easier to mitigate for a single pipistrelle male—common throughout the UK—using your site as an occasional summer roost than say, a large maternity colony of a rarer species of bat.
What does a bat survey cost in 2021?
Typically, preliminary roost assessment prices start from £299+VAT, as they represent around a day’s work. Emergence surveys involve several visits to the site, at night, normally by at least two surveyors (so all angles of the building are covered.)
This means that costs for the emergence survey are more expensive, typically costing in excess of £789+VAT as they represent around two-three or more day’s work.
Looking for a competitive quote? We all want the best price possible for services we get and not only are our costs are very low, but we have 16 years of experience doing this. If you use Arbtech, you’ll be guided through the preliminary roost assessment process by the best in the business whilst getting amazing value for money too.
Bat Surveys and the Law – How are Bats Protected?
All species of bat native to the UK are legally protected through their inclusion in Schedule II of the Conservation of Habitats and Species Regulations 2017 and Section 9 of the Wildlife and Countryside Act 1981.
Harming animals and or disturbing bats or their roosts is a criminally prosecutable offence. In 2020, a London division of Bellway Homes was fined £600,000 (plus court fees, the prosecution’s costs, and an award to the Bat Conservation Trust (BCT)) for the destruction of a bat roost without the appropriate licence in place.
Bat surveys and licensing are hardly what you might call “cheap”, but (speculating) a belt and braces approach might have cost a tiny fraction of that overall cost (not to mention the criminal record for the company executive held responsible); maybe 1/100th of the fine, or something like that. There is a considerable volume of additional, well-established case law supporting prosecutions for development disturbing bats, which twice has reached the Supreme Courts!
The take home point is that if you’re planning to impact upon buildings, trees and or other potential roosting sites in the course of your development, however insignificant the impact may seem, you have a legal obligation to avoid disturbing bats as you do so.
For more information on bat protection and licencing rules in England and Wales, as well as in Scotland and Northern Ireland, the government offers insight from or Environment, Food and Rural Affairs (DEFRA):
Natural England and DEFRA bat protection and licences
Our Expert’s legislation summary for UK species
Current bat protection laws make it illegal to:
- Intentionally kill, injure or capture bats
- Deliberately disturb bats, whether at roost or not
- Damage, destroy or obstruct access to bat roosts
- Possess or transport a bat or any part of a bat, unless acquired legally
- Sell, barter or exchange bats, or any part of a bat
European Protected Species Licence Applications: how they affect your scheme and schedule
On some occasions, if you have a bat survey done which shows that bats are present and you need to destroy a bat roost as part of your development, you will require a European protected species licence (EPSL) from Natural England.
The EPSL process is a separate process that can take up to six weeks. We can help with this process and have an outstanding record of getting EPSL applications approved.
Where a bat roost of low conservation value is present (i.e. small numbers of common bat species) a new type of licence is available (in England only). This is called a Low Impact Class Licence or a Bat Mitigation Class Licence.
This licence can be applied for in a much shorter time frame than a full EPSL, thereby preventing any delays to your development. Arbtech are able to offer licence applications to our clients for this type of licence thanks to our highly experienced consultants.”
The Bat Survey Guidelines and what they mean for you
So it follows that the industry guidance for deciding on what mitigation is appropriate is to conduct bat emergence surveys (also called activity or phase 2 surveys) In the UK, bats hibernate during the winter months, when the insects they predate upon are less abundant.
This means that these type of surveys are limited to summer months, typically (though not exclusively) anytime during May through September inclusive.
The bat surveyors use specialist bat detectors that record and convert bat echolocation calls into sounds we can hear and interpret. When bats are present on a site, activity surveys are conducted either as the sun rises or sets as it is when they can be seen to emerge or re-enter a roost.
In this way, our activity surveys and the corresponding report can show, scientifically, that the mitigation you propose as part of your planning application is adequate and appropriate to the species and population of bat, and the actual use of the site.

Later in 2021, the BCT are due to launch their updated guidelines for professional ecologists. This is widely expected to increase the demand for activity surveys in an effort to demonstrate probable-absence in the case of more esoteric species, as well as those more common but difficult to spot, such as common pipistrelle that roost in very small crevices.
This is in response to updated scientific study that relates to the the confidence with which surveyors can identify crevice dwelling species and their roosts from a preliminary assessment.
The inspection and reporting process
Your planning application, supported by a scoping survey report (and or emergence survey report) will enable you to secure a planning consent.
Under certain circumstances, you may require an EPSL for your proposed development, but that will not affect your planning application. So to summarise then:
- Get a preliminary assessment done.
- If you need to, get the bat emergence surveys done.
- Propose appropriate mitigation for bats in your application. (Read more.)
- Get your planning permission.
- Apply for an EPSL if applicable.
How do you choose a bat surveyor for your project?
Bat surveys must only be performed by a licensed bat consultant someone who is educated and trained to handle and disturb bats safely and has proven this to the powers that be.
A licence is issued to a ecologist by Natural England in England and the Countryside Council for Wales in Wales.
These two bodies are known as Statutory Nature Conservation Organisations. The licence essentially permits actions that would otherwise be unlawful e.g. efforts to disrupt bats or obstruct access to roosts —which you frequently do when visiting their habitats.

Without a licence from Natural England or the Countryside Council for Wales, a surveyor must retreat if they discover evidence of bat roosting, which is not much use to you, as the resulting report would be incomplete.
Further, without a licence, the surveyor may be judged to be incompetent and so have their report disregarded by the local planning authority.
Ask to see proof of your licensed bat consultant’s ecological qualifications, training and most importantly, a science and conservation licence (class 1 or better) for bats, issued by a SNCO.
Professional Indemnity insurance of £1m wouldn’t be a bad thing, either.
How are we different?
Unlike other ecologists, we only undertake planning and development related work, so our bat experts skills are not diluted over a multitude of disciplines and sectors.
All of our staff are also experienced, qualified and, in the case of our ecologists, licenced correctly by the Countryside Council for Wales or Natural England depending on their location.
We care the most about what matters to you: getting planning permission via the path of least resistance.
Still have questions about your bat surveys? Our common questions widget on this page will answer the most common questions we get…
Arbtech reviews – hundreds of them
We have hundreds of genuine 5 star reviews on our website, on reviews.co.uk and Trust Pilot. You can be absolutely sure your project is in good hands.