Who can carry out a bat survey and hold the licence

Anyone can look at a roof and see droppings. Only a licensed ecologist can lawfully carry out most of the survey work that follows, because every bat species in the United Kingdom is a European protected species and disturbing one, or entering a known roost, is an offence without a licence. So the answer to who can do a bat survey is narrow. It is an ecologist registered under a Natural England bat survey class licence, at a level appropriate to the techniques being used, and in practice one with the field experience to interpret what the detectors record.

The law that makes the licence necessary

Two pieces of legislation apply together. The Wildlife and Countryside Act 1981, as amended, protects bats and their roosts. The Conservation of Habitats and Species Regulations 2017 implement the European protected species regime, under which it is an offence to deliberately capture, injure or kill a bat, to deliberately disturb one in a way that affects its ability to survive, breed or rear young, or to damage or destroy a breeding site or resting place.

Two features of that regime surprise developers.

A roost is protected whether or not bats are present at the time. A summer maternity roost in a gable end remains a resting place in January.

And the offence does not require intent to harm bats. Carrying out roof works that destroy a roost is an offence even where nobody knew the roost was there, which is why the survey happens before the works rather than after someone finds a bat.

The two kinds of licence

The distinction matters because they sit at different points in a project.

A survey licence lets an ecologist do work that would otherwise be an offence, such as entering a roost, handling bats or using certain techniques. Natural England issues these as class licences at graded levels, and an ecologist registers under the level that covers the methods they use. A registered ecologist quotes their licence registration on their reports.

A mitigation licence, sometimes called a European protected species licence, is different. It authorises the development itself to damage or destroy a roost, and it is applied for after planning permission has been granted, because Natural England needs to know what has been permitted. Three tests must be satisfied: that there is an imperative reason of overriding public interest or a reason relating to public health and safety, that there is no satisfactory alternative, and that the action will not be detrimental to maintaining the favourable conservation status of the species.

There is also a class licence route for low impact works, under which a registered consultant can cover small roosts of common species without a bespoke application. It is quicker, and it is only available where the roost and the works fall within the defined limits.

Choosing and checking an ecologist

Ask for four things before you appoint.

• The Natural England survey licence registration and the level held.
• Membership of the Chartered Institute of Ecology and Environmental Management, and the grade of membership.
• Evidence of recent bat work of a similar type, with references.
• Professional indemnity insurance, since the report supports a planning application and a mitigation licence application.

Then ask a practical question. What will you do if the preliminary assessment finds moderate suitability in July? A good answer describes the number of emergence surveys the Bat Conservation Trust guidance would indicate, the months they must fall in, and what that means for the programme. A poor answer promises to work something out.

Cost is not the variable to optimise here. A survey that Natural England rejects at licence stage costs a construction season.

One further point on competence. A survey licence permits techniques; it does not by itself demonstrate that the ecologist can interpret what those techniques produce. Automated call analysis will happily assign a species to a poor recording, and an inspector or a licensing officer will notice when the conclusions do not follow from the data. Ask to see a redacted example report, and look at whether the survey results section explains the weather conditions, the equipment used, the surveyor positions and any limitations on the night.

The survey sequence and the seasons

The work runs in a set order, and the calendar controls it.

A preliminary roost assessment, sometimes called a preliminary ecological appraisal for the wider site, can be carried out at any time of year. It inspects the building and the surrounding habitat and grades the site for bat roost suitability as negligible, low, moderate or high.

Where suitability is above negligible, emergence and re-entry surveys follow. These take place between May and September, with May to August the optimal window, and the number of visits is driven by the suitability grading under the Bat Conservation Trust Good Practice Guidelines, currently in their fourth edition published in 2023. Low suitability typically needs one visit, moderate two and high three, spaced through the season.

Hibernation surveys, where relevant, run in the winter months.

The programme risk is the point to take away. A building assessed as having high bat roost suitability in late September cannot be fully surveyed until the following May, and a scheme that discovers this at planning submission stage loses most of a year. Commission the preliminary roost assessment at feasibility stage, not after the drawings are finished.

From survey to mitigation licence

Where a roost will be affected, the ecologist designs mitigation: bat boxes or integrated bat bricks, a replacement roost within the new structure, timing restrictions on works, a soft-strip method under supervision, and lighting designed to avoid illuminating flight lines and access points.

The mitigation is secured in the planning permission by condition, and then delivered under the licence. The licence application names the ecologist, who signs the method statement and takes responsibility for it. A Protected Species Survey prepared by anyone else does not substitute for that.

Be clear about this: a licensed ecologist is legally required for this work. An AI-assisted draft can structure the document, set out the policy framework and identify what the survey will need to cover, but it is a starting point for the professional rather than a substitute for the survey, the licence or the judgement. The professional directory is the route to a reviewer who can take that responsibility.

What the developer is responsible for

The licence sits with the applicant even though the ecologist prepares it, and the obligations follow the development.

Give the ecologist access to every part of the building, including lofts, cellars and outbuildings. Tell them about any works already carried out. Do not remove roof tiles, cut back trees or clear a barn before the survey, because destroying the evidence does not remove the offence and it makes the licence harder to obtain.

Follow the method statement on site, including the supervision requirements, and keep the records. Where conditions change and bats are found unexpectedly, stop work and call the ecologist. That instruction belongs in the contract as well as the report.

This is general guidance rather than legal advice, and wildlife offences carry criminal penalties. Check the position with a licensed ecologist and your local planning authority before relying on it.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.