Question 1

How much does a bat survey cost?

Accepted Answer

A Preliminary Roost Assessment (PRA) for a single building typically costs £300 to £600. For a larger site with multiple buildings or trees, fees range from £500 to £1,500. Emergence and re-entry surveys cost approximately £400 to £800 per survey visit, with the total depending on the number of visits required (one to three depending on roost potential) and the number of surveyors needed (determined by the size and complexity of the building). A full bat survey package for a barn conversion (PRA plus two or three emergence surveys) typically costs £1,500 to £3,500. Bat activity surveys for larger developments, involving transect surveys and static detector deployments over multiple months, can cost £3,000 to £10,000+. An EPS licence application, including the method statement and mitigation design, typically costs £2,000 to £5,000 on top of survey fees.

Question 2

How long does the process take?

Accepted Answer

The PRA can be conducted at any time of year and the report is typically produced within 1 to 2 weeks. However, if emergence surveys are required, these can only be conducted between May and September (with the optimal period being May to August). This means that if a PRA conducted in October identifies moderate or high roost potential, emergence surveys cannot be completed until the following May at the earliest, potentially delaying the planning application by 6 to 8 months. For this reason, it is strongly advisable to commission a PRA as early as possible in the project programme, ideally before or alongside the design process. An EPS licence application takes a minimum of 30 working days from submission to Natural England, and obtaining the licence before works can commence adds further time to the programme.

Question 3

Can I survey for bats in winter?

Accepted Answer

A PRA (daytime inspection) can be carried out at any time of year and is often a useful first step in winter to establish the baseline and plan the survey programme. However, dusk emergence and dawn re-entry surveys, which are the definitive method for confirming whether bats are roosting, can only be conducted during the active season (May to September). Winter hibernation surveys (inspecting buildings or underground sites for hibernating bats) are a separate survey type, conducted between November and February, and are only required in specific circumstances (such as works affecting cellars, tunnels, mines, or ice houses where hibernation is suspected). Static detector surveys for bat activity are also seasonal and are not valid outside the active season.

Question 4

What happens if bats are found during construction?

Accepted Answer

If bats or evidence of bats (droppings, urine staining, feeding remains) are discovered during construction works, all work in the affected area must stop immediately. It is a criminal offence to continue with works that would disturb bats or damage a roost. The site manager should contact a licensed bat ecologist, who will assess the situation and advise on next steps. If a roost is confirmed, an EPS licence from Natural England will be required before works can recommence. This can cause significant delays, which is why pre-commencement bat surveys are so important. In genuinely emergency situations, Natural England operates an emergency licence procedure, but this is not a substitute for proper pre-construction survey work.

Question 5

Do bat boxes actually work?

Accepted Answer

Yes, bat boxes are a proven and widely used mitigation measure. Woodcrete (wood-concrete) boxes such as those manufactured by Schwegler and Vivara Pro are the most effective and durable, with a lifespan of 20 to 25 years. Integrated bat bricks and bat access panels built into the fabric of new buildings are increasingly preferred by Natural England as they provide more permanent and thermally stable roost opportunities. The placement, orientation (south to south-west facing in most of England), and height (minimum 3 to 4 metres) of bat boxes are critical to their uptake. Monitoring studies show that bat boxes on buildings and trees can be colonised within 1 to 3 years, although uptake varies by species and local population. Natural England typically requires bat boxes to be installed before or during the construction phase, not as an afterthought.

Question 6

Do I need a bat survey for a loft conversion?

Accepted Answer

It depends on the building and its location. If the property is a modern house (post-1980s) in a suburban setting with no features suitable for roosting bats, a bat survey is unlikely to be required. However, if the property is an older building, is in a rural or semi-rural location, has a complex roof structure with potential access points, or if there is any evidence of bat use (droppings in the loft, for example), a PRA should be carried out before works commence. Even where planning permission is not required for a loft conversion (under permitted development rights), the legal protection afforded to bats still applies. Carrying out works that destroy a bat roost without a licence is a criminal offence regardless of whether planning permission was needed.

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