Introduction
- Project description
- Prior to the conversion of a redundant barn into an office / workshop, bat surveys recorded low numbers of common pipistrelle bats emerge from the roof. A EPS licence was therefore obtained for removing the roosts but incorporating similar features into the renovated building. Post-development monitoring surveys recorded a common pipistrelle maternity colony using the new provisions.
- Ecologist’s name and contact details
- Glyn Jones - I&G Ecological Consulting Ltd.
- Planning authority
- Carmarthenshire County Council
- Brief site description
- The barn to be converted was located on the west side of a farm yard in Rural Carmarthenshire. The farm itself remains at the base of a deep valley with substantial areas of woodland on
its upper slopes, a stream running along the valley, and a number of small fields abutting its banks. There is a good network of hedgerows around the fields.
Pre-works roost structure
- Type of structure
- Building
- Use
- Agricultural Building
- Condition
- Derelict
- Approx. age
- Unknown
- Main construction material of walls
- Stone
- Roof design
- Pitched Roof
- Roof material
- Slate
- Internal roof structure
- Timber Frame
- Lighting present on site and its proximity to the roost
- No lighting recorded
Pre-works roost description
- Species
- Common pipistrelle
- Number of bats max count
- 2
- Type of roost
- Transient Roost
- Evidence of bats
- Bats Recorded Emerging/Re-entering
- Roost location
- Gable Wall Tops
- Aspect of roost
- E
- Height of roost entrance (m)
- 6m
- Roost material(s)
-
- slateTiles
- Timber
- Stone
- Nearest commuting feature
- Hedge
- Distance to nearest commuting feature (m)
- 25m
- Nearest artificial light source to roost
- No lighting recorded
- Nearest artificial light source to roost commuting route
- No lighting recorded
Proposed works
- Description of works
- Due to the presence of small numbers of roosting bats, a EPS licence was obtained to remove the baseline roosts and compensate by integrating like-for-like provisions into the renovated build. Re-roofing work was completed under ecological supervision.
- Type of impact upon the roost
- Long-Term Roost Modification and Roost Loss
Proposed mitigations
- Type of mitigation
- Compensation
- Specific technical detail of measure
- Continuous access was provided behind the weatherboards by leaving gaps of 12-40 mm wide along the lengths of the gables and eaves. No fly screens were used at these points.
- Relevant annotated figures
- Roost location
- Behind Barge Board
- Aspect of roost
- E
- Height of roost entrance (m)
- Up to 6m
- Roost material(s)
-
- Bitumen Felt
- Stone
- Other
- Nearest commuting feature
- Hedge
- Distance to nearest commuting feature (m)
- 25m
- Nearest artificial light source to roost
- No lighting recorded
- Nearest artificial light source to roost commuting route
- No lighting recorded
- Type of mitigation
- Compensation
- Specific technical detail of measure
- 4 x Schwegler bat tubes were built into the wall sections in the course of the wall repairs.
- Relevant annotated figures
- Roost location
- Bat Box
- Aspect of roost
- S
- Height of roost entrance (m)
- Up to 3.7m
- Roost material(s)
-
- Other
- Nearest commuting feature
- Hedge
- Distance to nearest commuting feature (m)
- 25m
- Nearest artificial light source to roost
- No lighting recorded
- Nearest artificial light source to roost commuting route
- No lighting recorded
Monitoring data
- Length of monitoring proposed
- No monitoring proposed
- Type of monitoring
- Roost Inspection
- Date and time
- 20th June 2017
- Evidence recorded
- Numerous common pipistrelle roosts (and at least one soprano pipistrelle roost) were recorded throughout the wall tops of the converted barn, including a maternity roost of at least 49 bats at the southern gable apex. Individual common pipistrelles (one each) were also recorded using two of the newly-installed bat tubes. It was not clear to what extent these roosts were related to another nearby common pipistrelle maternity colony in the main farmhouse. It is possible that bats were switching between the two locations.
- Interventions made
- None
Final details
- Lessons learned
- No need to over mitigate if the existing features are replicated as closely as possible then they seem to be more readily used and more quickly discovered. There were signs of use at this location 1 year post development and roost feature use has increased greatly.
