The Biodiversity Net Gain Journey

Updated 30 January 2024. This page provides an overview of the PAS experience of biodiversity net gain and defines the "journey" that local authorities are taking to operationalise it, providing links to further resources and good practice.

Our experience of working alongside local authorities has led us believe that biodiversity net gain (BNG), and getting to the point where net gain can be delivered, is a journey for local authorities.

A local authority may start this journey at different points, depending on factors like local plan status, available resources and expertise or political and corporate priorities. To meet the statutory minimum required when BNG becomes mandatory (12 February 2024 for major TCPA development), an authority will need to be ready to receive and determine planning applications that deliver at least 10% biodiversity net gain, as measured by the Biodiversity Metric. However, to realise the full benefits of BNG and optimise its potential, a local authority will also want to think about some of the other steps we outline below.

We have set this out as a diagram that we hope will help local authorities in developing their approach to BNG. Feedback on how we can best support local authorities on this journey and the content of these pages is welcomed! Please email Beccy Moberly

Graphic with boxes showing a progression for delivery of biodiversity net gain from a legal minimum of being able to determine planning applications with 10% biodiversity net gain up to a Local Plan that evidences mitigation choices and means BNG is optimised to deliver wider benefits
PAS Biodiversity Net Gain Journey for Local Authorities

We have also been thinking about what this means for local authorities in terms of where to focus their activity and what work needs doing. We think there are seven key areas of activity for local authorities on this BNG journey:

  • Corporate embedding of BNG as a priority
  • Development of place-making principles around BNG
  • Development of local strategy and evidence
  • Embedding in Local Plans and Strategic Planning
  • Establishing Development Management arrangements
  • Delivery of schemes
  • Monitoring and reporting of progress

Defra have also set out 10 actions local planning authorities can take to prepare for Biodiversity Net Gain (BNG) and we have drafted a BNG readiness checklist to to help LPAs structure an approach to preparing for mandatory BNG. A recording of a session in July 2023 on BNG for Planners which PAS's Beccy Moberly contributed to with The Planner and Environment Bank is available on The Planner website.

We have resources available on: Biodiversity Net Gain in Local Plans and Development Management, including examples from local authorities implementing BNG now.

Cornwall Council are one of the local authorities already implementing a biodiversity net gain approach. This presentation from Helen Fearnley for The House Briefing event on Preparing for Biodiversity Net Gain in June 2022 outlines what they are doing on their journey and is available to view and as a PDF. The slides cover why Cornwall Council adopted biodiversity net gain before it becomes mandatory and lessons learnt in applying BNG in practice, including delivering BNG off-site, working with others and the importance of collaboration.

PDF of presentation from Helen Fearnley, Cornwall Council Ecologist on their approach to Biodiversity Net Gain


PAS's Beccy Moberly also presented at the same event in June 2022 on biodiversity net gain and the planning system. You can view or download her slides, which cover the PAS BNG project, BNG and the planning application process and what we have heard from local authorities.

PAS slides on What does BNG mean for the planning system from June 2022