St Mary’s Hospital: Bat Mitigation Solutions


In 1910 the Gateshead Corporation purchased part of the West Duddo Estate and a new 500 capacity asylum was subsequently built at the site, which is located to the south of the market town of Morpeth in Northumberland.  Since its construction the site has variously been used as a military hospital, sanatorium and to house patients requiring mental health treatment.  The hospital eventually closed in 1995 and since then it has remained in a state of abandonment but with on-site security protection.

In 2007 Bellway Homes and Rivergreen Developments were given the go-ahead by the Government for the construction of a ‘business village’, including new houses, offices and craft workshops, a bistro, a community centre and improved sports, play and transport facilities for local people. The development was put on hold in 2009 as a result of the economic down-turn that occurred at that time.  Development has since recommenced within the site.

The redevelopment of the St Mary’s Hospital site has involved the phased demolition and construction of buildings.  The proposals also include the restoration of the formal lawns and existing landscaping within the site.

BSG Ecology’s role in the project

In 2007 BSG Ecology was appointed by Bellway Homes to carry out comprehensive bat surveys to inform an ecological impact assessment (EcIA) for the proposed development.  Although the site had had security protection since its abandonment, over the years general neglect and vandalism had created an environment that was perfect for roosting bats.  As a result, the overall likelihood of bats being present was considered to be very high.

During the early stages of the project the survey work was significantly constrained by the presence of asbestos and the unsafe condition of many of the buildings.  Consequently the surveys at this time consisted of external building inspections and bat activity surveys that covered the exterior of the buildings.  In 2008, following the completion of asbestos removal and a full structural survey, BSG Ecology was able to gain access to the interior of the buildings to fully assess the importance of those buildings for roosting bats.

Following the initial baseline surveys, BSG Ecology secured a number of European Protected Species Licences to permit the exclusion of bats prior to the phased demolition of buildings and the commencement of the re-development works.  The use of multiple licences reflects the complex phasing of the works.  The licensing process involved the completion of further bat activity surveys and the provision of advice to Bellway Homes about mitigation and compensation requirements.


At an early stage in the project it became evident that the various buildings supported a large number of roosts for four species of bat: common pipistrelle, soprano pipistrelle, brown long-eared and a Myotis species (thought to be Natterer’s bat).  Although none of the roosts was particularly large (the largest was a soprano pipistrelle roost of 15 bats) there were many of them, they were widespread and they included a number of maternity roosts.

Even though access to the buildings was originally limited, BSG Ecology gathered comprehensive data on bat distribution that allowed a robust impact assessment to be carried out.  The results of this assessment were used to help secure planning permission for the development.

BSG Ecology worked closely with the project architect to look at the mitigation and compensation requirements for bats during the various phases of the development.  During the initial site preparatory works, which included the demolition of various buildings, it became evident that securing a European Protected Species Licence was not going to be straightforward.  The number of roosts present and their distribution in most buildings meant that interim mitigation and compensation measures would need to be considered.  This involved enhancing retained buildings to make them more attractive to bats prior to excluding bats from their roosts and demolishing the buildings containing the roosts.  This allowed part of the site to be cleared in advance of new development.

Before any further demolition could take place, new bat roosts had to be provided in the dwellings that were subsequently constructed within the site.  The development has therefore progressed in a series of phases whereby bats have only been excluded once alternative roost opportunities have been provided.

The development has now reached a final phase with regards to bat mitigation and compensation, whereby the remaining roosts in retained buildings will now need to be excluded to allow work to proceed.  This will involve a final European Protected Species Licence application that covers all remaining bat roosts, but which will also need to consider the overall situation within the site to ensure that all displaced bats are fully accommodated.

In parallel with the licensing requirements for bats, BSG Ecology has provided advice on landscaping requirements to ensure that bats continue to have a good range of feeding opportunities and that habitat connectivity is maintained and enhanced around the site.


Bellway Homes and Rivergreen Developments

Key Services

North East, Residential/ Commercial Development