BI8Implement and monitor Biodiversity Net Gain (BNG)

Biodiversity Net Gain (BNG) is now a mandatory framework in the UK under the Environment Act 2021, requiring developments to enhance biodiversity. Developers must demonstrate that their projects deliver at least a 10% net gain in biodiversity compared to the pre-development baseline. The goal is to leave the natural environment and its biodiversity in a better state than before.

BNG applies now to all categories of development for which planning permission is required (excluding exemptions set out in secondary legislation) and includes a framework for assessing impacts to biodiversity using a biodiversity accounting system, the DEFRA Biodiversity Metric.

Biodiversity and climate change are closely linked, and BNG plays a vital role in mitigating climate change through carbon sequestration by restored ecosystems, ability to adapt and recover from extreme weather events enhancing climate resilience, provision of key ecosystem services such as pollination, water purification, soil stability, cooling urban areas reducing the heat island effect and lowering energy demand.

To ensure effective implementation and monitoring of BNG, the Council is aiming at working in the following actions:

• Embed BNG into the Stevenage Borough Local Plan (SBLP) policies, ensuring conformity with national guidance and legislation.
• Make BNG a material consideration in planning applications.
• Identify priority areas and opportunities for biodiversity enhancement, such as degraded habitats, or underused urban spaces.
• Monitor and enforce BNG compliance.
• Track and monitor BNG implementation and progress in Stevenage.