Biodiversity net gain

Wentworth, Jonathan

doi:10.58248/pn728

Biodiversity net gain

Wentworth, Jonathan

Authors

Jonathan Wentworth

Contributors

Dr Jennifer Dodd J.Dodd@napier.ac.uk
Other

Abstract

Mandatory biodiversity net gain (BNG) is a new requirement in addition to existing biodiversity and wildlife planning policy. The 2019 impact assessment for the policy states that developers causing the most environmental damage should face the highest costs to steer development towards the least damaging areas and designs.

A baseline survey maps the size, state and presence of differing patches of vegetation types on a development site using the UK Habitat Classification system. The BNG metric, set out in secondary legislation, is used to determine the value of these habitats in “biodiversity units”; the pre-intervention score. Using the metric, biodiversity gain plans demonstrate how the developer will deliver a minimum of a 10% gain in these units; the post development score. These planned units can be on the development site, off the development site or delivered through the purchase of statutory credits as a last resort.

A 2024 NAO report found widespread support for mandatory BNG, but that implementation risks were also being raised. The majority of habitat creation and enhancement is projected to occur on development sites. Researchers suggest this may not deliver optimal outcomes for nature recovery objectives, and more holistic approaches are needed to restoring habitats strategically across landscapes are required. The NAO set out risks local authorities will not be able to discharge legal, compliance and enforcement obligations in relation to BNG, as a result of challenges such as insufficient access to ecological expertise.