Acer Ecology was commissioned to undertake a bat survey of a residential building. The owners had requested planning permission to build a one-storey extension, install external insulation and add sky-lights.
House before Works
Three flight surveys were undertaken on the building: two dusk emergence surveys and one dawn re-entry survey. Three common pipistrelle bats (Pipistrellus pipistrellus) as well as two soprano pipistrelles (Pipistrellus pygmaeus) were recorded accessing a roost via the soffit box along the south-eastern gable end of the building. The roost was classified as a non-maternity summer roost used by a low number of male or female bats for day roosting purposes. All subsequent works were undertaken under a European Protected Species (EPS) license.
A supervised soft strip of the roof was undertaken, followed by installation of appropriate bat mitigation into the roof area. External roosting provisions were created under raised ridge tiles. Gaps were created leading into the new soffit box along the same south-eastern gable end as before. One Schwegler 2F bat box was left hanging in perpetuity on the adjacent tree in the garden.
One interesting aspect of post-mitigation checks is that people often unknowingly create additional gaps for bats. There are nearly always usually a few raised tiles along the edges of the roofs, or some gaps under raised ridge tiles present.
Crevice dwelling bats, such as pipistrelles, love these gaps and can enjoy both the dedicated areas for bats and accidental crevices which were created in the course of development works.
Our guide to bat mitigation can be found here. For more articles on the mitigation that we have conducted, please see the following links: Bat mitigation Forest of Dean and Bat mitigation St Tewdrics.