We are often asked what bat surveys are needed for loft conversions and extensions to houses, so here is a simple guide.

Bats can roost in houses, typically in the loft spaces, cavity walls, or under hanging tiles or weather boarding. The places where bats roost are protected by law from damage, destruction and obstruction of access, even if bats are not present at the time.

If a loft conversion or other change to the house could affect a bat roost, then a bat survey will be needed before the planning application is submitted. The first stage is an external and internal inspection of the building by a suitably qualified and experienced ecologist. This can be completed at any time of year. If there is any evidence of use by bats or if the building is considered to be suitable for bats, further bat emergence/re-entry surveys will be required between May and September.

The good news is that the presence of bats does not usually prevent the development from taking place, provided that measures are taken to avoid disturbance to bats and that any roosts lost are compensated for by providing alternative roosting sites either in the new structure or an alternative place nearby. If a bat roost is found, a licence will be required for to undertake any works that will impact on bats in a way which would otherwise break the law. The licence can be obtained once planning permission has been granted.