Blenheim Estates, Oxfordshire: Protected Species and Ecological Clerk of Works Support


BSG Ecology was instructed by Blenheim Estates to conduct an extended Phase 1 habitat survey for a proposed development within the estate. The proposals included the conversion of a complex of farm buildings to business use and construction of 27 new residential units within an improved (poor quality) hay meadow. The survey identified that various protected and priority species were present or had potential to use the site including nesting birds and roosting bats in the buildings and reptiles and amphibians in the meadow.

BSG Ecology’s Role in the Project

Further surveys were conducted for bats, birds, reptiles and amphibians using relevant industry standard guidance, and an Ecology Report was prepared to accompany the planning application.

BSG worked closely with the client and design team to facilitate the development and highlight potential ecological constraints such as issues relating to nesting birds and roosting bats early within the design process. This ensured the issues could be resolved in a timely manner and mitigation measures compatible with the proposed development could be designed and implemented at low cost. For bats this included use of Bitumen F1 roofing felt (rather than breathable roofing membranes), installation of three external bat boxes, incorporation of a bat loft and provision of bat access points beneath ridge tiles. A European Protected Species Mitigation (EPSM) licence for bats was secured once planning permission was obtained to enable works to the farm buildings to be undertaken taking into account the anticipated effects upon bats and their legal protection status. Mitigation and enhancements were also provided for nesting birds.

Roofing works were phased with teams of contractors being brought onto the project in stages as the works progressed. Prior to contractors starting works on site, a Toolbox Talk was provided by the licenced ecologist or an Accredited Agent. This included details of the legislation afforded to bats, where they were found within the site and how works should proceed to avoid an offence. Construction of the bat loft was overseen by an ecologist to ensure the features being incorporated would provide suitable conditions for the re-establishment of a maternity colony of brown long-eared bats.

Slow-worm and common lizard were recorded on the boundaries of the species-poor meadow in very low numbers. A hibernaculum was constructed in an area of the site to be retained and enhanced as part of the proposals. Habitat manipulation works were undertaken to encourage individual reptiles to disperse to adjacent suitable habitats including the newly created hibernaculum. This was followed by a destructive search under a watching brief by an experienced Ecological Clerk of Works to prevent the killing or injury of any individual reptiles which remained within the site. Two common toads were rescued and no reptiles were encountered during the works.


Throughout the course of the works three brown long-eared and five common pipistrelle bats were encountered within the farm buildings and were safely relocated to the installed bat boxes. The project is due for completion on schedule in March 2017 and post-construction monitoring will take place in summer 2017 and 2018.


Blenheim Estates

Key Services

Heritage, South East