What is a bat survey?

nightime bat survey


A bat survey may be required if you are converting, renovating or modifying a building, or removing any trees that have the potential to support roosting bats. A Preliminary Roost Assessment would be undertaken initially to determine if the trees or buildings, and sometimes structures, have the potential to support roosting bats. If the tree/ buildings do hold potential, nocturnal bat surveys would be undertaken to identify if there are any bats roosting. This would also determine what type of bat roosts are present.

When a survey is undertaken, it will determine which species of bats are present, the bat’s access points in and out of the building, how many bats are present within the building and lastly when and how the bats are using the building. You will need a qualified bat ecologist to undertake the surveys.

What if bats are present?

If bats are found within the building/ structure or tree, a bat license from Natural England will be required to relocate the bats and their roost. Mitigation will need to be implemented which could be in the form of bat boxes, or bat boxes integrated into proposed buildings.

What is a bat survey

What time of year can you do a bat survey?

You’re able to survey buildings trees and structures for the potential presence of bats all year round. Bats can be identified from droppings, dead bat carcasses, urine staining and bits of prey just as moth wings. Potential roosting habitat can also be identified all year round.

If bats are identified, or there is potential for them to be present, dusk emergence and dawn re-entry surveys can be undertaken. Bat surveys can be undertaken from May to September following best practice guidelines published by the bat conservation trust (Collins, 2016). Bat surveys cant be undertaken in the rain, or when the temperature is below 10 degrees.

Do I need a bat survey for planning permission?

If your proposals include the demolition or modification of a building, or the removal of trees, then it is likely you will need a bat survey to inform planning permission. This would initially be in the form of a Preliminary Roost Assessment which is undertaken in the day time. If bat potential, or the presence of bats is identified, the further surveys would then be required in order to inform a planning application, and any associated mitigation.

construction bat survey

Are Bats Protected?

All Bats within the UK are protected under UK and European legislation and local authorities are required to assess if any bat species will be affected by a development proposal. This is the reason why they could ask you to submit a bat survey along with your planning application. The current law for the protection of bats make it illegal to do the following:

  • Deliberately disturb bats, if they are at roost or not
  • Damage, destroy or obstruct access to bat roosts
  • Intentionally or deliberately kill, injure or capture bats
  • 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

Here in the UK, we have 18 species of bats, 17 of which are known to be breeding here. Every summer, thousands of people venture out into nature to experience the wonder of bats in their natural habitat.

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