Castell Coch: Bat Survey & Licence Implementation


BSG Ecology has been providing ecological support and advice to Cadw, the Welsh Government’s historic environment service, on a number of important projects in Wales since 2007. These have included the conservation and refurbishment of a number of historic buildings, including Bishop’s Palace (St. David’s, Pembrokeshire), Coity Castle, Kidwelly Castle, Caerphilly Castle, Laugharne Castle, Beaupre Castle, Neath Abbey, Dinefwr Castle and Castell Coch.

Castell Coch is a Victorian Gothic Revival castle that is managed and maintained by Cadw. This impressive structure contains a courtyard flanked by three four-storey towers with tall conical roofs: the Keep, Kitchen and Well Towers. They each incorporate a series of apartment rooms, many of which are ornately decorated and furnished. The castle walls are buttressed by a thick sloping stone wall that rises from the moat. The castle is set within an extensive area of ancient woodland that is part of the Cardiff Beech Woods Special Area of Conservation (SAC) and also the Castell Coch Woodlands Site of Special Scientific Interest (SSSI).

Conservation works required the replacement of roofing tiles and the construction of a complex scaffold structure with weatherproof sheeting to protect the structure during the works period (as well as to shield the works from visitors at this busy tourist attraction).

Our role in the project

BSG Ecology was commissioned by Opus International Consultants on behalf of Cadw to carry out bat survey work at Castell Coch in order to assess the potential impacts on bats of planned conservation works. These included the Gallery walkway roof on the northern side of the courtyard, as well as the Kitchen Tower where conservation work may be necessary in the future. The survey work covered all accessible areas of the castle and included daytime inspection surveys as well as automated bat detector surveys in the Kitchen and Keep towers and emergence/re-entry surveys.

The surveys identified a number of bat roosts within the site, with at least six species confirmed as roosting: common pipistrelle, soprano pipistrelle, brown long-eared bat, serotine, greater horseshoe bat and lesser horseshoe bat. As well as numerous locations supporting small numbers of roosting bats, we identified a breeding colony of brown long-eared bats in the Kitchen Tower during the summer, and around thirty common pipistrelle bats hibernating behind beams around the courtyard in the winter.

Working closely with the clients and the construction team, BSG Ecology successfully devised mitigation and method statements to ensure compliance with European and domestic wildlife legislation, and secured a European Protected Species (EPS) licence to carry out the conservation works. It was important to make sure that bats were considered throughout the implementation of the conservation works and we were able to ensure that bats were adequately protected and that the works proceeded to schedule.

EPS Licence implementation

Throughout the work, BSG Ecology oversaw and advised the project team on the implementation of the EPS Licence. Because the Gallery walkway is an important flyway, particularly for brown long-eared bats, the works area had to be carefully sealed to exclude bats and prevent them becoming trapped within the scaffold structure. Careful checks were carried out to ensure that this did not take place. In addition the works were carefully timed to avoid particularly sensitive periods for bats, such as the breeding and hibernation seasons.


The works to the Gallery roof were completed on time during September-December 2013. The success of this project demonstrates the value of working closely with clients to gather a robust baseline of data. It also shows that careful planning to secure and implement an EPS licence having respect to our clients’ wider project objectives can lead to a straightforward delivery of both the works and legal compliance with regard to protected species.




Key Services

Heritage, Wales