Introduction
- Project description
- Conversion of redundant farm buildings for residential use with demolition of others; impacts to Day Roosts of six bat species, including Lesser Horseshoe. Bespoke mitigation included a dedicated Bat house, roost retention and new roost creation.
- Ecologist’s name and contact details
- Tyrer Ecological Consultants Ltd
- Client’s name
- Bespoke Group
- Planning authority
- Cheshire West & Chester
- Brief site description
- A former cattle farm north-east of Chester containing 10+ buildings surrounded by grazing pasture, arable grassland, hedgerows, mature broadleaf standards, ponds and ditches.
Pre-works roost structure
- Type of structure
- Building
- Use
- Agricultural Building
- Condition
- Not In Use
- Approx. age
- circa 60-100 years.
- Main construction material of walls
- Brick
- Roof design
- Pitched Roof
- Roof material
- Slate
- Internal roof structure
- Timber Frame
- Lighting present on site and its proximity to the roost
- Absent of artificial light.
- Photos or annotated figures of roost structure
Pre-works roost description
- Number of bats max count
- 16
- Type of roost
- Day Roost
- Evidence of bats
- Bats Recorded Emerging/Re-entering
- Roost material(s)
-
- Brickwork
- Bitumen Felt
- Slate Tiles
- Timber
- Nearest commuting feature
- Treeline
- Distance to nearest commuting feature (m)
- 75
- Nearest artificial light source to roost
- 42
- Photos or annotated figures of roost
Proposed works
- Description of works
- Without the implementation of mitigation, initial impacts by the proposed conversion of two large Barns at the Picton Barns Farm site would result in the loss of several Day Roosts used by singular/small numbers Common Pipistrelle (10), Soprano Pipistrelle (1), Brown Long-Eared (1), Natterer’s (1), Daubenton’s (1) and Lesser Horseshoe (1).
- Type of impact upon the roost
- Long-Term Roost Modification and Roost Loss
- Relevant annotated figures
Proposed mitigations
- Type of mitigation
- Mitigation
- Specific technical detail of measure
- A stand-alone roost to be constructed to the east of the new development and close to foraging habitat, orientated east – west lengthways to provide varying temperatures over the active season; it will be timber frame construction with external tantalised pre-treated rough sawn timber cladding with internal coarse sheet timber lining the walls to internal dimensions of 5 metres long x 4 metres wide and an external height of 4.5 metres; a loft/void is not required as the full interior will be available for bat use. Roof construction will be reclaimed rough sawn timber as opposed to new timber, purlin and rafter design without timber trusses to allow unrestricted flight for loft dwelling bats. The roost will have a pitched slate roof beneath which traditional bitumen underfelt will be installed. A lockable door will be installed for any future monitoring or maintenance with a notice that identifies it as a dedicated bat roost and not to be entered by persons who do not hold a bat licence.
Gable elevations of the new roost to a distance of 1 metre down from the apex will be lined with traditional bitumen underfelt with rough sawn timber cladding fixed to vertical battens with several gaps of 15 – 18 mm to allow access for crevice dwelling bats between the timber cladding and underfelt. Two access points, 70 mm wide x 25 mm deep, one on each of the gable elevations.
The roost(s) will be permanent and dedicated for bats; they will not be used for any other purpose. Lighting will not be directed at or close to the roost areas nor will it affect nearby foraging places or flight lines.
Additionally, Permanent roost provisions will be incorporated into converted buildings B and D in the form of two integrated bat boxes and ridge tile access per build. Two integrated bat boxes will be installed onto the southern gable elevations of both building B and D (one on each), whilst two ridge access will be created at ridge level on both structures to the south and central aspects of the buildings with the incorporation of bitumen 1F underfelt beneath ridge tiles; the dimensions of bat access at ridge tiles will be 15-18mm width.
- Relevant annotated figures
- Roost location
- Bat House
- Aspect of roost
- Various
- Height of roost entrance (m)
- 1.5
- Roost material(s)
-
- Bitumen Felt
- Timber
- Nearest commuting feature
- Treeline
- Distance to nearest commuting feature (m)
- 1
- Nearest artificial light source to roost
- 80m+
- Nearest artificial light source to roost commuting route
- 80m+
- Photos or annotated figures of roost
Actual mitigations implemented
- Type of mitigation
- Mitigation
- Specific technical detail of measure
- Changes to be made following future monitoring.
- Roost location
- Bat House
- Aspect of roost
- Various
- Height of roost entrance (m)
- 2.8
- Roost material(s)
-
- Bitumen Felt
- Timber
- Nearest commuting feature
- Treeline
- Photos or annotated figures of roost
Monitoring data
- Length of monitoring proposed
- 2
- Frequency of monitoring
- x1 survey per year
Final details
- Lessons learned
- Following the first round of monitoring, modifications will be added where necessary.
Perseverance and adaptability is key.
