Temple worked with Horsham District Council to provide the evidence base, focused on specific development typologies and sites in the emerging local plan at the District level, to inform a potential policy to raise the minimum Biodiversity Net Gain requirement above the mandatory 10% across the county and constituent Local Authorities. The basis of this work was in recognition that Horsham District has suffered serious and sustained declines in wildlife and biodiversity largely due to pressure from developments, and it sought to put a greater emphasis on improving the value of existing biodiversity, as well as robustly implementing a large-scale nature recovery strategy.
The study reviewed potential allocations in the Local Plan, and representative potential windfall sites, and proposed and reasonable development scenarios to model reasonably achievable levels of Biodiversity Net Gain. These values were used to inform what change in net-to-gross ratios would be needed to deliver different target levels of net gain, along with costs for alternatively delivering any shortfall offsite.
The project also included a ‘green call for sites’ – an investigation into the capacity within the district to deliver any necessary off-site habitat enhancement to offset biodiversity losses through development. This involved developing a questionnaire, hosted on a dedicated website, which was disseminated to local landowners to collect information on the availability of land for biodiversity enhancement to offset the impacts of developments and deliver biodiversity net gain in the district.
The study showed that the majority of sites would be able to deliver near to, or in excess of 12% net gain, with the relative impact of additional costs or reduction in development capacity being unlikely to be significant in most cases.
The green call for sites showed that there is ample capacity and willingness among landowners within the District to deliver any offsetting that would be required arising from developments in the local plan.