Introduction
Biodiversity Net Gain (BNG) is an approach to development that ensures that wildlife habitats are left in a measurably better state than they were before the development. In England, BNG became mandatory under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021) in Spring 2024.
PAS has been working with local planning authorities (LPAs) to support their implementation of BNG since 2021. LPAs are taking a variety of approaches to ensure they comply with the legal requirements and, in many cases, go above and beyond these to ensure BNG delivers wider benefits.
This is one of a suite of guides prepared for PAS by Urban Design Learning that collate good practice across the following key areas of implementing BNG:
- Local Plans, local policy and advice notes
- Monitoring and enforcement
- LPAs and planning applicants working together
- Faster decision-making
This guidance on making the most of scarce ecological expertise presents good practice gathered through interviews with LPA officers from across the country, including those using in-house specialists and LPAs who source external specialist support via Service Level Agreements (SLA).
Understanding whether a planning application meets BNG requirements is a new and often complicated part of the decision-making process for planners. Ecological and biodiversity specialists are in short supply so approaches to involving them on planning applications should ensure they have manageable workloads, avoid risks to delivery should specialist expertise not be available, and make sure that BNG can be taken into account alongside other planning considerations.
The guide sets out lessons learnt to better integrate BNG as ‘business-as-usual' for development management officers and others involved in the implementation of BNG. This report collates good practice from LPAs making best use of their ecological and biodiversity specialists.
Validation
Lessons Learnt
The above case studies offer valuable lessons for authorities concerning validation:
- Effective BNG implementation does not require complex systems: act quickly when problems emerge, keep solutions simple and practical, and work with existing processes rather than against them.
- Robust validation is essential: particularly for authorities with scarce ecological resources. Validation alone cannot solve the problem and must be part of broader strategy including continuous officer training to address changes in policy.
- Efficient validation and guidance processes are critical: when ecologist time is scarce investment in digital tools such as Mycelia can provide good return on investment for streamlining processes.
- Engage with applicants: informal discussions provide better results than guidance alone. Consider proactive outreach to regular applicants and their consultants and provide formal training sessions when launching new validation requirements. LPAs could help address external consultant skills gaps through knowledge sharing.
- Invest in training: training validation staff to catch basic errors and inconsistencies protects specialist ecology time and improves the quality of formal consultations.
- Checklists must be usable by non-specialists: accept that some poor submissions will get through and focus on catching the most egregious errors. Avoid requiring ecological judgement for basic validation and pay particular attention to exemption verification as this is a high-risk area for applications bypassing proper scrutiny. Staff turnover is a major risk to validation effectiveness so document everything and build institutional resilience.
- Review discharge validation procedures: While validation has significantly improved, discharge validation remains an area requiring ongoing attention and guidance. Review applications to verify baseline accuracy and compliance with both mandatory BNG requirements and local policy. Standardised templates can be used to recommend the biodiversity gain condition as an informative, with optional habitat management and monitoring plan conditions in line with LPA requirements.
Internal Guidance for Officers
Lessons Learnt
The above case studies offer valuable lessons for authorities developing their own internal guidance:
- Early engagement is essential: involving biodiversity specialists at the validation stage ensures consistent quality of submissions and reduces delays later in the process. This front-loaded approach prevents applications from progressing too far with inadequate information.
- Context is important: internal procedure notes should be tailored to local circumstances while addressing core legislative requirements.
- Making strategic decisions about which applications receive detailed review makes efficient use of available resources: guidance should include review mechanisms to allow for continuous improvement.
- Guidance helps make best use of resources: comprehensive guidance documents reduce the need for repeat bespoke advice and improve the quality of submissions. This frees up specialist ecologist time to address more complex issues requiring professional judgment.
- Invest in training: comprehensive training, accessible documentation and collaboration between ecology specialists and planning teams is essential for practical implementation of guidance.
- Set clear expectations: guidance documents set clear expectations for the submission of planning-related documents and provide templates for applicants to follow.
The Use of Regulatory Tools
Resource Management: Training
Resource Management: Technology
Lessons Learnt
Lessons for addressing the resource challenge through technology include:
- Technology should support efficient workflows: when evaluating software, consider which staff need access and at which stage of the process.
- Procure the right tools: a small specialist team can support a high-volume authority if the right software is in place to distribute initial assessment tasks more widely, and if structured support mechanisms exist for the officers handling day-to-day casework.
- Simple workflow habits matter: basic actions like updating case status in Mycelia make a difference to how effectively the specialist can monitor and manage the caseload. Embedding these habits through targeted training is worth the investment.
Key contributors
Many thanks to the following for contributing towards this guidance document:
- Bath and North East Somerset Council
- Buckinghamshire Council
- Bournemouth, Christchurch and Poole Council
- Cornwall Council
- Dover District Council
- Essex County Council’s Place Services
- Greater Manchester Ecology Unit
- Northumberland County Council
- North Northamptonshire Council
- North Yorkshire Council
- Peterborough City Council
If you are part of a local authority and would like more information, contact PAS at [email protected] and sign up to the BNG Network.