BNG Good practice in Local Plans, local policy and advice notes

Bournemouth, Christchurch and Poole Council (BCP) developed their draft BNG guidance to address a policy gap following the rejection of their Local Plan. The guidance was created to provide a practical framework for implementing BNG requirements despite the absence of adopted Local Plan policies. The document serves multiple purposes including establishing expectations for applicants and consultants, supporting development management officers in handling BNG applications, and laying the groundwork for future policy preparation and adoption.

The guidance was developed over a 12-month period, entirely in-house with the planning policy team leading the work. The document was designed to sit underneath what would have been Local Plan policies on BNG and green infrastructure (GI), including an Urban Greening Factor (UGF) approach. It provides essential structure for managing BNG in a large authority with limited ecological resources.

Challenges

BCP faced several challenges in implementing BNG. As a large unitary authority formed in 2019, the Council has an outdated Local Plan following the rejection of their new Local Plan on duty to co-operate issues. Also, with only one ecologist for the entire authority, there was significant resource pressure in dealing with BNG and Development Management (DM) officers were struggling to take responsibility for BNG applications.

Approach

The BNG guidance was drafted to bridge the policy gap while awaiting the new Local Plan to progress.  

BCP's approach included creating draft validation checklists to standardise application requirements and reduce ecologist workload. This was addressed through business planning to justify dedicated BNG officer time and resource, though this was complicated by proposed Government changes to thresholds. The Council developed a Design Guide to sit underneath Local Plan policies, which DM officers could reference despite the lack of adopted policy.  

The draft guidance helped pro-actively manage the high volume of planning applications with BNG being received by the authority and officer participation in the Planning Advisory Service (PAS) Network, was “absolutely invaluable” for sharing best practice.

Lessons Learnt:

• Informal guidance can help bridge policy gaps, but works best when the Local Plan includes formal BNG and other greening policies. Whilst guidance without formal policy backing is a very valuable resource for officers, it “doesn't quite have the teeth” needed to direct applicants to deliver exemplary BNG, particularly where applicants are not actively engaged in the process.
• Don’t underestimate the importance of internal documents: design guides and validation checklists are valuable tools to ensure consistent, efficient working practices within the authority, even without full policy backing.
• Use available resources: PAS network participation is essential for keeping pace with evolving BNG requirements and the nuanced interpretation of the regulations.
• Remember to future-proof: resource planning must account for potential policy changes, requiring a well-managed and flexible approach to addressing change. However, the current uncertainty over changes to BNG regulations and the impact on future workload makes it difficult to justify dedicated BNG officer posts and the cost of bespoke BNG software tools like Mycelia.
• Consider how BNG guidance can support tree protection strategies, particularly if the proposed changes to thresholds are implemented. The potential loss of BNG requirements for smaller sites was seen as particularly problematic for tree protection, with no mechanism to get them replaced.

North Northamptonshire Council developed strategic significance guidance to address a policy vacuum during the early implementation of statutory BNG. The BNG metric user guide advises that where a Local Nature Recovery Strategy (LNRS) has not been published, planning authorities should specify alternative documents (such as Biodiversity Action Plans, River Basin Management Plans, or Green Infrastructure Strategies) for applicants to use when assigning strategic significance in their metric calculations. Without these, applicants can self-assign strategic significance with any justification they choose, potentially undermining the achievement of genuine biodiversity gains. Previous challenges with outdated Special Protection Area guidance, which had not kept pace with new evidence, had forced the Council to resort to ad hoc measures causing confusion for both the Council and developers. Learning from this experience, the authority determined that proactive guidance was essential for the implementation of statutory BNG.

The Principal Project Officer covers two authorities: North Northamptonshire and West Northamptonshire. The guidance was developed to cover both authorities, however, only North Northamptonshire adopted and published the guidance on their website. Consequently, applicants in West Northamptonshire assigned their own strategic significance with their own justifications. For example, a quarry extension application in West Northamptonshire included applicant-assigned strategic significance that showed a net gain of the statutory 10% minimum. However, if the guidance had been applied, the metric would have shown only 4% net gain, failing to comply with the legislation. The officer had to accept the applicant's metric despite recognising it did not deliver the biodiversity gains that properly assigned strategic significance would have achieved.

Development

The guidance was developed through a review of existing policy frameworks and strategies, utilising officers practical experience with development proposals and understanding of landscape-scale habitat creation needs. The guidance addresses several critical areas including strategic co-ordination to prevent fragmented habitat creation that lacks ‘landscape-scale’ coherence and habitat prioritisation by identifying which habitats should be assigned strategic significance. Location criteria specifies where habitat creation should be prioritised, ensuring BNG contributes to strategic biodiversity goals.

Challenges

Developing and implementing the guidance presented several challenges including preparing the guidance ahead of the LNRS with limited resources. By adopting the guidance, it enabled consistent application across all relevant planning applications. North Northamptonshire was able to evaluate proposed BNG delivery against strategic objectives and ensure consistent and appropriate strategic significance assignment, preventing gaming of the metric through inappropriate strategic significance claims and delivering genuine strategically beneficial BNG that meet legislative requirements. The guidance has since been superseded by the authority's published LNRS, which now provides the framework for strategic significance assessment.  

Lessons Learnt  

• Act early: develop guidance proactively before problems emerge and leverage established policy frameworks and strategies.
• Don't wait for perfect information: work with available evidence (including Environmental Records Centre data) while building the evidence base as the difference between having and not having specified guidance can be substantial.
• Learn from experience: policy vacuums should be anticipated and addressed proactively rather than reactively. Learning from previous policy challenges can inform better approaches to new requirements.
• Think strategically: consider landscape-scale implications from the outset. Authorities without published LNRS should specify alternative documents for strategic significance assignment or risk applicants self-assigning inappropriate values.
• Managerial support: obtain support from senior officers to develop necessary frameworks and use professional judgment and initiative, all of which are essential when developing novel policy approaches.
• Publishing and formally adopting guidance is essential: developing it is not sufficient if not made available to applicants.

For more information on the Strategic Significance multiplier, please see LNRS & Strategic Significance Multiplier Transition | Local Government Association 

Peterborough City Council is a unitary authority covering an extensive area with diverse habitats, including Jurassic limestone country, the Nene Valley, the urban area of Peterborough, and fenlands. The interim approach was developed before Biodiversity Net Gain became a mandatory aspect of the planning system. It was created as a training tool to introduce the concept of BNG and associated terminology to planning agents and officers, rather than as formal policy to prevent application backlogs.

The approach was developed over approximately 48 hours and took the form of a short policy document of 3-4 pages. Whilst the interim document did not go through a rigorous governance process, it was shared with DM officers at team meetings and communicated via the Council website as light-touch advice for applicants and used primarily as a teaching tool for planning agents.  

The interim approach was intentionally limited in scope. It introduced the biodiversity metric as a tool for measuring biodiversity value and encouraged applicants to demonstrate no net loss or 10% net gain using the metric rather than through subjective assessments. The interim approach did not include condition text for securing BNG and did not specify detailed requirements for how BNG should be delivered within planning applications. The advice was not rigorously enforced, and applications with incomplete or missing information were accepted at face value.

Lessons Learnt:

When BNG became mandatory, Peterborough's rate of invalid applications due to missing BNG information was slightly lower than in other Cambridgeshire authorities, suggesting the interim approach had some positive effect as a training tool. With hindsight, the Council would reconsider developing interim guidance before full implementation details are available to avoid confusion. The Council recommend that other LPAs invest time in providing training to agents and applicants to minimise time spent on assessing applications.

Bracknell Forest is a small unitary authority in Berkshire, southern England, centred on the towns of Bracknell and Sandhurst. The Council has developed a comprehensive approach to implementing BNG, focusing on clear guidance, efficient processes, and cross-team collaboration. With their Local Plan adopted in 2024, the Council created practical guidance for developers that consolidates requirements into a single accessible document, reducing time taken on decision-making within the planning application process and ensuring development schemes consider BNG from the outset. The Council’s approach addresses several key challenges including limited ecological expertise, evolving national guidance, and the need for effective communication between planning policy, development management, and biodiversity teams.  

The Council addresses BNG implementation through a cross-departmental team that includes planning policy officers who oversee BNG implementation, ensuring processes are in place across different parts of the authority. The team meets weekly to discuss BNG matters and coordinate policy, process and responses to planning applications across the authority. This approach builds on the Council's experience of bringing forward Suitable Alternative Natural Greenspaces (SANGs) since 2006 as part of the Thames Basin Heaths strategic mitigation project.  

The Developer Guidance Document  

Prior to mandatory BNG, the Council recognised it had limited guidance available for developers and lacked a local validation list. This led to the creation of a single guidance document to support developers and streamline the application process. Please note that this document is likely to be superseded following the planned publication of the Council’s Biodiversity and Green Infrastructure Supplementary Planning Document in June 2026.  

In 2023 the team considered creating a Supplementary Planning Document (SPD), a more formal document that provides detailed guidance on Local Plan policies. However, as an SPD requires extensive consultation and is difficult to update, a more flexible, developer guidance document was prepared that could be updated more readily as national policy evolves.  

The guidance document is intended to be concise despite its comprehensive scope, consolidating BNG requirements into a single accessible resource, including when BNG applies and what is exempt, submission requirements and validation criteria, encouraging pre-applications, the biodiversity metric and how to use it, on-site and off-site delivery options, local habitat banking opportunities and monitoring and enforcement expectations.

Challenges

Several challenges were addressed in producing the guide including evolving national guidance, limited ecological resource, timing pressures, balancing detail and flexibility, and possible future guidance. Despite the challenges and recent potential policy changes, Bracknell Forest Council remains committed to effective BNG implementation. The team continues to refine internal processes based on experience, progress habitat banking projects, share learning with other local authorities and advocate for clearer national guidance, particularly on reciprocal arrangements.  The forthcoming Biodiversity and Green Infrastructure SPD will update the guidance and respond to evolving national policy.

Lessons Learnt  

The Council’s experience demonstrates both the potential benefits and significant challenges of BNG implementation at the local level. Lessons learnt include: 

• Communication is essential: the most important lesson is the need for regular, structured communication between planning policy, development management, and biodiversity officers. Weekly meetings ensure everyone understands requirements, shares challenges, and maintains consistency. Meetings between local authorities across Berkshire is also useful so that LPAs can learn from each other.
• Flexibility over formality: choosing developer guidance over a formal SPD early in the process allowed the Council to be more responsive to changing national policy. While SPDs carry more weight, they’re harder to update, which would have been problematic given the evolving BNG landscape around the time that BNG became mandatory.
• Clear, consolidated guidance speeds decisions: by bringing all BNG requirements into one accessible document, Bracknell Forest has reduced confusion, improved application quality, and enabled faster validation and determination. Developers have clear expectations from the outset.

Cornwall Council is a unitary planning authority located in the southwest of England. The Council introduced a local BNG policy ahead of the national mandate through its Climate Emergency Development Plan Document (DPD), adopted in early 2023. Policy G2, which sits within this DPD, required 10% BNG for major applications. This was brought forward in response to the Council's declaration of a climate emergency in January 2019, which gave officers a clear direction to progress environmental planning policy. The DPD forms part of a suite of planning documents that together make up Cornwall's Local Plan, alongside the Cornwall Local Plan 2016, the Minerals and Waste Plan, and Neighbourhood Plans. The Council is currently information-gathering for a new Local Plan.  

Approach

Policy G2 was developed by the planning policy team, working closely with the DM team and a BNG Specialist Officer. The Policy requires 10% BNG for major developments, with the intention that this would apply to minor applications once mandatory national BNG came into force. A key feature of the DPD was the deliberate sequencing of related environmental policies. Policy G2 on BNG is followed by the tree canopy cover policy, which requires major developments to provide canopy cover to 15% of the site area. This ordering was intentional; by presenting the policies together, the DPD makes clear to developers that they can be used in conjunction. Trees planted to meet the canopy cover requirement can also count towards BNG gains, reducing the perceived burden of compliance.  

Member training on BNG was carried out in advance of national mandatory requirements, meaning that by the time mandatory BNG came in, members were already familiar and comfortable with the policy.  

The DPD also references the Local Nature Recovery Strategy (LNRS), for which Cornwall was a pilot authority and the lead body. This integration means that BNG delivery, tree planting, and nature recovery priorities are all connected within a single coherent framework. An Urban Greening Factor (UGF) policy was also considered during the DPD process but was not taken forward. This may be revisited as part of the new Local Plan.  

Current Status

As of January 2026, Policy G2 has largely been superseded by national mandatory BNG requirements. The 10% figure, the 30-year requirement, and the obligation to have regard to the LNRS are all set nationally. What remains of local value is part 3 of the Policy, which includes provisions that development should have regard to local priorities for nature set out in the adopted LNRS, and should avoid the best and most valuable agricultural land for BNG. The practical value of the policy now lies less in its specific requirements and more in its role as a signposting document. By sitting alongside the tree canopy cover policy within the DPD, it helps developers understand how multiple environmental obligations interact and can be met together, rather than as separate and competing demands.  

Lessons Learnt  

This case study offers important lessons for other local authorities:

• Early adoption builds resilience: introducing BNG before the national mandate meant Cornwall was well-prepared when mandatory requirements arrived. Officers and members were already experienced with BNG, reducing the disruption of transition.
• Policy integration adds value: placing BNG policy alongside the tree canopy cover requirement within the DPD gave developers a clearer picture of how obligations work together. This reduces confusion and can help applicants find more efficient ways to meet multiple requirements simultaneously.  
• Local policy can be overtaken by national requirements: authorities that invest in local BNG policy should be aware that national policy can supersede local thresholds and requirements. The lasting value of a local policy may lie in its contextual provisions rather than in numerical targets.  
• Member buy-in is easier when training precedes the mandate: Cornwall trained all Members on BNG ahead of the national requirement coming in. As a result, BNG was already a familiar concept when it became mandatory, making the transition smoother for planning committee decisions.

Durham County Council is a unitary authority in the Northeast of England. The Council declared an ecological emergency in April 2022, which provided the impetus for developing comprehensive biodiversity guidance. The authority is also the responsible authority for the Local Nature Recovery Strategy (LNRS) due for completion in March 2025. The Supplementary Planning Document (SPD) was driven by the planning policy team and supported by DM, who sought additional advice and clarification on the LPA's position on biodiversity. The SPD was formally adopted in April 2025.  

Approach

The SPD was developed entirely in-house from initial conception in 2023 to formal adoption in April 2025. It was led by the ecology team working closely with the planning policy team. The development also involved cross-departmental collaboration with DM, highways, drainage, and regeneration teams. The work was spread over approximately 18 months, with the ecology team accepting reduced delivery in other areas during this period. The flexibility of in-house production meant work could be scheduled around peaks in planning application workload. Durham also participates in a regional group of LPA ecologists across the Northeast. The group meets regularly to maintain consistency in BNG requirements across the region.  

The Council reviewed other authorities' SPDs, identifying elements they considered good practice and expanding upon them to meet Durham's specific needs. The SPD covers BNG requirements and validation, nutrient neutrality (a significant local issue), habitat regulations assessments (due to numerous designated sites in the County), protected species surveys and mitigation, Green Infrastructure (GI) design and delivery, and validation checklist requirements.  

Consultation

The SPD underwent two formal consultation stages:  

• Stage 1: 6-week consultation period (June-July 2024)  
• Stage 2: 7-week consultation period (November 2024 to January 2025)  

The consultation received generally positive feedback. However, some planning agents objected to language encouraging applicants to exceed the 10% BNG statutory minimum where possible. Consultation feedback suggested that any language perceived as potentially impacting on development viability receives negative response, even when the SPD contained no mandatory requirements beyond statutory minimums. The team recognised the need to reframe biodiversity guidance in terms of de-risking applications and expediting the planning process. Rather than promoting biodiversity features as inherently valuable, the message should emphasise that providing high-quality information upfront and incorporating recommended features will result in faster planning decisions with fewer information requests. This language shift, from nature conservation to planning efficiency, better resonates with the SPDs primary audience of applicants.  

Challenges

The key challenge that the County faced was the poor quality of ecological information submitted with planning applications. The lack of basic ecological information required extensive back-and-forth correspondence before substantive ecological review can begin. To address this, Durham developed a pre-validation process working with their DM team. Using the Idox system, DM officers can flag applications for the ecology team to review before formal validation, allowing officers to identify missing documentation early in the process and preventing validation of incomplete applications.  

Another significant challenge was getting the development sector to engage with consultation and, ultimately, to read and use the SPD. The team found that those already interested in biodiversity were easy to engage but often not the primary audience. Recognising that the SPD itself is a passive document, the team developed a more active communication strategy. They created concise "crib sheets", highlighting the most common issues encountered in planning applications. These were sent directly to all known ecological consultants working in the area and have been updated twice since BNG implementation. The team considers these targeted communications potentially more valuable than the SPD itself in driving behavioural change.  

Replicability

Durham's approach is replicable for other authorities who benefit from the following resource and management approach:  

• In-house ecological expertise: an ecology lead with sufficient technical knowledge and writing capability.  
• Internal collaboration: ability to draw on in-house expertise from planning policy, highways, drainage, and other teams.
• Management support: buy-in from planning policy and senior management teams and acceptance that the team will operate reduced delivery in other areas during SPD development.

Lessons Learnt  

This case study offers important lessons for other local authorities:

• Frame guidance from the audience's perspective: the primary audience (developers and planning agents) respond better to messages framed around planning efficiency and risk reduction rather than nature conservation values.  
• Target engagement strategically: focus engagement efforts on the professional audience who are the target of the SPD. Make engagement as easy as possible and recognise that you will primarily reach those already willing to engage.  
• Continuous training and communication: establish regular training with DM officers to provide updates on changing requirements and ensure consistent understanding.  
• Regional collaboration adds value: engage with regional officer networks. Consistency across authorities reduces confusion for planning agents working across multiple authority areas.  
• The SPD assumes a good quality baseline for applications: however, the reality is that many applications lack basic information. Focus initial efforts on validation checklists, pre-application advice, and consistent enforcement of minimum information requirements before investing time in supplementary guidance.  
• In-house development provides flexibility: Developing the SPD in-house, while requiring staff time, provides cost savings and flexibility that would not have been achievable with external consultants. The ability to pause, adapt, and control timescales around other work pressures is valuable, and the cost savings can be significant.    

Dover Council is a district-level authority within Kent County. It has emerged as a leader in implementing BNG requirements, being ahead of other authorities in developing comprehensive guidance and procedures. The Council's success stems from employing an in-house ecologist who proactively guides green policy through the Local Plan process and prepares practical operational guidance for both internal teams and external applicants. The authority has successfully moved beyond basic compliance to create a framework that encourages early consideration of BNG, supports better outcomes, and provides clear expectations for applicants. While challenges remain, Dover's work provides a strong model that other authorities can learn from and adapt to their own circumstances.  

Dover recognises that BNG implementation is a 'work in progress', an evolving practice requiring continuous learning, adaptation, and refinement rather than a fixed set of procedures. This mindset, combined with practical tools and collaborative working, positions Dover well to navigate both current challenges and future policy changes.  

The BNG Policy  

The Policy was primarily developed by the planning policy team working on all aspects of the Local Plan. One temporary officer was employed for approximately two years to handle environmental aspects of the Local Plan, including the natural environment, landscape, and climate change.  

Dover's BNG policy was developed through the Local Plan process. Adopted in October 2024 the Local Plan includes strategic policies for ecology and biodiversity and a specific BNG Policy (Policy NE1) which includes a locational hierarchy for BNG delivery, requirements for post-development BNG proposals to be submitted with applications and a clear structure comprising preamble, policy, and implementation sections.  

Consultation

At the consultation, some developers argued that the policy went beyond mandatory national requirements and that the Council should not include additional local requirements. Natural England expressed concerns that the locational hierarchy conflicted with the biodiversity gain hierarchy. However, Dover's view was that it enhanced the hierarchy by making it more locally applicable. The Examiner accepted a revised version of the Regulation 19 policy, effectively supporting Dover's approach.  

Kent Nature Partnership (facilitated by Kent County Council) commissioned a report examining whether 20% net gain would be viable compared to the 10% mandatory minimum. The evidence showed that the main cost is achieving 10%, with the additional 10% being a relatively small proportional increase. However, Dover did not adopt the 20% requirement due to viability concerns in some areas, particularly Dover town where even affordable housing provision is challenging.  

Successes

The Policy has helped Dover secure BNG information at an earlier stage in the planning process. While BNG is primarily a post-consent matter (except for baseline), the policy enables the Council to understand how BNG will be delivered, encouraging developers to think about implementation earlier rather than leaving it to pre-commencement conditions. This early consideration leads developers to prepare more coherent approaches to development proposals and helps avoid viability challenges later when costs are reviewed.  

Dover's Local Plan indicated the authority would prepare additional BNG guidance.  

Guidance is preferred over SPD as the policy team anticipate that developers will give guidance the same weight as an SPD. Guidance avoids the time and cost associated with mandatory consultation requirements, whilst allowing voluntary consultation with all stakeholders, and is more appropriate to explain the process of BNG implementation without adding additional substantive requirements to the development process.  

Future guidance will aim to provide applicants with an explanation of what BNG is and why and where Dover wants it and include the minimum information requirements for applicants. In addition, ecologists will be provided with interpretation guidance, data collection standards, and how to present information in reports to help the Council.

Replicability

The policy and approach are replicable elsewhere if it reflects the current national planning context. The purpose of a Local Plan is to make national requirements locally applicable, and Dover's approach demonstrates how this can work for BNG. The implementation section could be strengthened, and the policy would benefit from better differentiation between application types, clearer wording on biodiversity gain plans and stronger links to validation requirements.  

Lessons Learnt  

This case study offers important lessons for other local authorities:  

• Early developer engagement is critical: developers who consider BNG early produce better applications.
• Local context matters: the locational hierarchy adds local applicability to national requirements, making the policy more relevant to Dover's specific circumstances and priorities.  
• Stand the ground: despite opposition from developers and late concerns from Natural England, the Planning Inspector supported Dover's approach, validating the local enhancement of national policy.  
• Standardisation is key: creating standardised conditions and decision notice templates makes the process manageable for officers and clearer for applicants.  
• Take advantage of professional networks: the Planning Advisory Service (PAS) BNG forum has been invaluable, enabling idea-sharing and prompting high standards.  
• Training is never finished: BNG knowledge requires continuous development as understanding evolves and new staff join.  
• Work in progress: Even without proposed national changes, the approach continues to evolve as learning develops about what support developers need from the planning authority.   

East Devon District Council operates within Devon’s current two-tier system. Despite the current uncertainty over reorganisation, the Council continues to undertake its planning role including BNG and strategic environmental planning work. The District has been a supporting authority in the production of Devon’s LNRS, which is currently at its final stages of sign-off.  

East Devon’s Local Plan is currently at Regulation 19 Consultation. The Council is progressing planning to enable the delivery of a second new community in the District, which brings resource challenges and additional complexity to the planning process.

BNG Guidance  

The BNG guidance was developed to support DM officers who needed to understand and implement the new BNG requirements. It was designed to be accessible to planning officers without specialist ecological knowledge, while maintaining technical accuracy. In addition, the guidance aimed to support consistent and proportionate handling of BNG at validation and determination stages.

Initial drafting of the guidance was undertaken by the ecology team, drawing on their ecological expertise and their understanding of the regulatory requirements. The draft was then shared with DM officers for feedback to ensure it addressed their needs in a clear, concise manner. This approach allowed for quick turnaround of the guidance while ensuring the content was practical and relevant to users.

The guidance provides a step-by-step walkthrough of the BNG process, including when BNG applies to different types of applications, how to assess BNG submissions, e.g., for validation, how to check for deliberate degradation, and what constitutes acceptable BNG provision.

BNG Local Plan Policy

East Devon has taken a progressive approach by setting a 20% BNG target in their Local Plan policy, going beyond the statutory 10% minimum. This decision was driven by several factors:

• Political support: the Council has strong political backing for ambitious environmental targets, with Councillors viewing it as the right thing to do in the context of the Climate Emergency.
• Strategic ambition: the 20% Local Plan Policy target demonstrates the Council’s commitment to exceeding minimum standards and the Council’s broader environmental goals and aspirations for nature recovery.
• Feasibility: the target only applies to major developments and is considered achievable based on the local environment and emerging offsite market.

It remains to be seen whether the proposed 20% BNG target will be accepted by the Planning Inspector at the Local Plan Examination. However, the Council is confident that the policy will provide significant environmental benefits for the area if adopted.

Implementation

East Devon has been pragmatic in implementation, recognising that not all development can achieve high BNG percentages on-site. For example, the Council would prefer development proposals that classify recreational space as modified grassland and commit BNG to a local habitat bank, rather than provide species-rich grassland in heavily populated housing areas where it will not survive everyday use.

East Devon considers that habitat banks are essential to achieving the 20% target for BNG. The Council recognise that large developments may struggle to achieve 20% on-site provision and habitat banks are a practical way to deliver off site provisions locally with better ecological outcomes.  

This pragmatic approach balances ambitious policy targets with realistic delivery mechanisms, helping facilitate sustainable development while achieving meaningful environmental gains.

Lessons Learnt

• Strong political support enables ambitious targets: East Devon’s 20% BNG policy target is underpinned by Councillor support.
• The statutory baseline helps: the 10% BNG requirement creates a common understanding that makes higher local targets more acceptable.
• Pragmatism is essential: setting ambitious policies must be balanced with realistic approaches to implementation.
• Habitat banks are key enablers: off-site provision is critical for achieving higher BNG targets practically and with better ecological outcomes.
• Accept uncertainty: a proactive approach means moving forward with sound policies despite some uncertainty about the outcomes of the Local Plan Examination.
• Internal collaboration can be effective: the BNG guidance was developed quickly and efficiently through internal collaboration between ecology and planning teams.

Peterborough City Council is a unitary authority covering an extensive area with diverse habitats. Development patterns are varied, with most applications being either very small (1-10 houses) or very large (new townships), and significant conversion of agricultural land to industrial uses.

The Draft BNG Policy Approach

The draft BNG policy takes a deliberately simple and streamlined approach. Rather than replicating statutory requirements already set out in national legislation, the policy focuses exclusively on local requirements and clarifications specific to Peterborough.

The approach aims to reduce invalid applications and consultation requirements by providing clear, upfront guidance on local expectations. The policy focuses on clearly defined statistical metrics rather than subjective interpretations. Supplementary guidance documents provide detailed clarifications on specific BNG implementation issues.

The Council's approach involves a short core policy document supplemented by additional guidance documents. This structure was developed through meetings with policy officers to ensure the policy remains concise while still providing necessary detail. The core policy sets out the local BNG percentage requirement of 20% and a definition of significant enhancement as well as a justification based on financial viability assessment undertaken by external consultants.

Supplementary documents outline detailed guidance on habitat definitions and classifications as well as clarifications on complex BNG situations (e.g., when a dead tree counts as a tree in the metric) and an expanded explanation of significant enhancement expectations.

Rationale

The streamlined approach recognises that ecology and biodiversity are interpretive subjects, unlike engineering where specifications can be precisely defined. By separating statutory requirements from local policy, the Council avoids making the Local Plan unnecessarily lengthy while ensuring applicants have access to detailed guidance where needed. This structure also provides flexibility to update supplementary guidance as BNG implementation evolves, without requiring changes to the adopted Local Plan policy text.

Current Status

A complete draft biodiversity policy has been prepared for inclusion in the new Local Plan. Whilst Peterborough has had guidance that they should not be aiming above the 10%, the Council will test a 20% net gain policy but with further caveats that it can be changed based upon viability. Development of supplementary guidance documents is ongoing.  

Lessons Learnt

• Have a simple, focused policy: this can prove to be more effective than comprehensive documents that replicate statutory requirements.
• Supplementary guidance can provide the necessary detail without lengthening the core policy.
• Ensure clear upfront guidance on local expectations: this reduces invalid applications and consultation burden.
• Separating statutory requirements from local policy requirements creates clarity for applicants.  

Salford City Council adopted a BNG policy in January 2023 as part of their Local Plan Development Management Policies, ahead of the Environment Act requirements. The Policy requires major developments to deliver a 10% net gain in biodiversity. This achievement was built on extensive preparatory work conducted at the Greater Manchester (GM) level with support from the Greater Manchester Ecology Unit (GMEU), including evidence gathering through case studies of recent developments, consultation with stakeholders and the production of comprehensive guidance documentation. The policy development benefited from strong sub-regional collaboration, consultancy support and iterative refinement based on stakeholder feedback, particularly from the development industry.  

The Council’s BNG policy represents a forward-thinking approach to biodiversity planning, developed within the context of GM’s collaborative governance structure. The policy initially stated that "development must produce a net gain in biodiversity," but evolved during the policy development process to specify " all major development shall deliver at least a 10% net gain in biodiversity value" aligning with emerging national standards before they became mandatory.  

Approach

The development of Salford's BNG policy was significantly enabled by preparatory work conducted at the GM level. This sub-regional approach involved building an evidence base through examination of case studies of actual development projects and applying biodiversity metrics retrospectively to existing developments to assess what would have been required to achieve net gain.  

The Council produced a comprehensive GM guidance document on BNG and provided consultancy support and training for DM and policy officers to understand BNG implementation. This provided Salford with a robust platform from which to develop their local policy, drawing on shared learning and resources across the combined authority area.  

The policy underwent significant evolution during its development:

• Initial version (c.2018): general requirement that "development must produce a net gain in biodiversity"  
• Revised version (pre-publication): specified "All major development shall deliver at least a 10% net gain in biodiversity value" in response to emerging national policy direction  
• Adoption (January 2023): adopted as Policy 18 (Biodiversity and Geodiversity) in the Local Plan Development Management Policies.  

Consultation

The Council received significant pushback during the draft plan consultation stage (Regulation 18, c. 2018). At this time, BNG was not yet widely understood or accepted within the development industry. Key concerns raised by stakeholders included viability concerns about the cost implications of delivering 10% BNG, questions about the evidence base supporting the policy requirement and concerns about implementation practicalities and market readiness.  

In response to consultation feedback, the Council undertook additional evidence gathering before the Regulation 19 publication stage, which included review of Defra viability reports and impact assessments on BNG requirements, analysis of planning appeal decisions that referenced BNG, examination of Local Plan examinations where BNG policies were tested and documentation of best practice from other authorities pursuing BNG policies. This enhanced evidence base helped demonstrate the soundness and viability of the policy approach, addressing stakeholder concerns and strengthening the policy for examination. By the Regulation 19 publication consultation stage, opposition to the BNG policy had significantly diminished. The strengthened evidence base, combined with growing national awareness and acceptance of BNG principles, meant that the policy faced minimal objection during this final consultation phase. No specific modifications to the BNG policy were required following the publication consultation.  

Challenges

Being ahead of national requirements presented some implementation challenges. The development industry and some consultants were not initially prepared for BNG requirements, leading to initial resistance and implementation difficulties. GMEU, while supportive, experienced significant workload increases. Being an early adopter meant they faced capacity challenges before BNG became mainstream. Additionally, both Council officers and external consultants needed time to fully understand and consistently apply the policy, particularly when it preceded national requirements.

Salford also produced a comprehensive background topic paper on biodiversity, which consolidated the evidence base supporting the BNG policy, explained the rationale for the 10% requirement, documented responses to consultation feedback, and referenced national and sub-regional context for BNG implementation. This document served as a key supporting evidence document during the Local Plan examination process.  

Additional Supporting Materials  

While not producing a separate SPD specifically for BNG, Salford's approach integrated BNG guidance within broader planning documentation such as:  

• Validation requirements specifying when BNG assessments are required  
• Planning application guidance referencing the GM guidance documents  
• Internal guidance for DM officers on assessing BNG proposals  

Lessons Learnt  

Based on Salford's experience, the following lessons learnt and recommendations emerge for other local authorities:  

• Shared resource development: pooling expertise and resources to develop comprehensive guidance reduces the burden of individual authorities. The collaborative approach in GM proved highly beneficial.  
• Consistent standards: a unified approach across GM created clarity for developers working across multiple authority areas.  
• Integrate policy and implementation teams: strong working relationships between policy and DM teams proved essential. Policy officers physically sitting alongside DM teams facilitated quick resolution of implementation questions, generated regular interaction between and continuous dialogue between both, and helped to establish a close working relationship.  
• Collective voice: A coordinated sub-regional approach carried more weight with stakeholders and at Examination.
• Be prepared for initial resistance: understand that ambitious policies may face stakeholder resistance initially, but this often diminishes as the policy becomes better understood and evidence strengthens.
• Respond to consultation constructively: use consultation feedback, even pushback, as an opportunity to strengthen evidence and refine policy wording.
• Build comprehensive evidence: invest in robust evidence gathering, including case studies of built schemes, viability analysis, and reference to national studies and emerging best practice.
• Consider resource implications: anticipate increased workload for ecology consultees and ensure appropriate capacity is in place or being developed.  
• Provide clear guidance: support policy with practical guidance for applicants, whether through SPDs, topic papers, or validation requirements.
• Allow policy to evolve: be willing to refine policy wording between consultation stages based on evidence and emerging national policy direction.   

South Tyneside Council developed a BNG policy to address the unique challenges of the small, urban borough. The Council sought to create policy that establishes a locational hierarchy that prioritises BNG delivery within borough boundaries while remaining compliant with national frameworks. The Council addressed several challenges in implementing the BNG policy including the limited geographic size that restricts opportunities for on-site and local off-site BNG delivery, the Council’s predominantly urban character that limits available land for habitat creation and enhancement, participation in a multi-authority LNRS arrangement that creates complex cross-boundary considerations, and habitat matching and spatial multiplier calculations.  

The spatial risk multiplier (SRM) reflects the relationship between the location of biodiversity loss and the location of its compensation, penalising offsite habitat compensation according to its distance from the development. This would allow developers to deliver BNG relatively far from development sites while technically meeting the requirement to be ‘as close as possible’. For a small borough like South Tyneside, this could result in developments occurring within the borough while all associated biodiversity gains are delivered elsewhere, providing no local environmental benefit.  

Approach  

The BNG policy was developed as part of South Tyneside's Local Plan process. Key timing factors influenced the policy's development.  As the Statutory Framework was published relatively late, just before the Regulation 19 consultation in January 2024, this timing, while challenging, provided sufficient opportunity to embed the framework's requirements into the emerging policy. The NPPF guidance included provisions allowing local authorities to build upon the statutory framework, which lead to the locational hierarchy approach.  

The key innovation of South Tyneside's BNG policy is its locational hierarchy, which prioritises where biodiversity gains should be delivered. The hierarchy aims to “put South Tyneside front and centre in where BNG should be delivered”, addressing the limitations of national policy for small urban authorities.  The locational hierarchy presents 3 priorities:

• Priority 1: On-site delivery wherever possible.  
• Priority 2: Off-site delivery within South Tyneside borough boundaries.
• Priority 3: Off-site delivery outside the borough only when the above options are not available or feasible.  

The Council's approach was pragmatic, using national policy to shape the local policy rather than requiring extensive new evidence gathering.

Consultation

As part of the Local Plan preparation, the BNG policy underwent Regulation 19 consultation in January 2024. The consultation generated limited feedback from the general public, which the Council interpreted positively as indicating general acceptance. Development industry representatives argued that the locational hierarchy simply duplicates existing national policy requirements. However, the Council maintains that the policy provides necessary specificity and place-based clarity that national guidance does not adequately address for small urban authorities.  

The Local Plan has progressed to the Examination in Public (EIP) stage:  

• Examination hearings took place in July 2025 and January 2026, where the BNG policy was specifically discussed.  
• Key Examination questions focus on whether the policy merely repeats national policy and whether it is justified.  
• The Planning Inspectorate will determine whether the policy should remain as drafted or requires modifications.  

The Council believes the policy serves important local functions but acknowledges it must survive the rigorous testing of the EIP process. Findings of the Examination are expected in Spring/Summer 2026.  

Current Status

Recognising that the locational hierarchy policy requires available BNG units within the borough, South Tyneside is actively working to create supply through Council-led habitat banking initiatives which include identifying and developing potential habitat bank sites on Council-owned land. South Tyneside is engaging Northumberland County Council as the responsible body for habitat bank registration, conducting preliminary assessments of suitable sites for habitat creation and enhancement, and working to ensure habitat types match likely demand from development sites.

To inform both the Local Plan and habitat banking strategy, the Council commissioned a high-level needs and opportunities assessment. This was a desk-based study using aerial photography to assess habitats on potential allocation sites. Worst-case and best-case condition assessments were conducted to establish ranges of baseline units for each site and a similar analysis was conducted on potential BNG delivery sites to understand uplift opportunities. The analysis included consideration of habitat types to ensure supply would match demand. While this work did not directly feed into the locational hierarchy policy itself, it has proven valuable in demonstrating that BNG has been considered through the plan making process.    

Challenges  

Several challenges remain at this stage:  

• Examination outcome: The policy must survive Planning Inspectorate scrutiny regarding justification and potential duplication of national policy  
• Supply sufficiency: Whether enough biodiversity units can be created within Borough boundaries to meet demand remains to be seen  
• Habitat type matching: Ensuring that created habitat types align with the types of units needed by developers  
• Flexibility requirements: Balancing the desire to keep BNG local with practical realities of limited supply  
• Market dynamics: Understanding how private habitat banking markets will develop and interact with council-led initiatives  
• Long-term management: Establishing sustainable arrangements for 30-year habitat management and monitoring  

Lessons Learnt  

This case study offers important lessons for other local authorities:

• Timing matters: late publication of national frameworks created challenges but also provided opportunities to incorporate the latest guidance.  
• Place-specific approach: small urban authorities face unique challenges that may not be adequately addressed by nationally standardised approaches.  Small LPAs have genuine constraints that may justify more prescriptive local policies.  
• Policy as part of system: BNG policy cannot work in isolation, it requires supporting actions to create supply and understanding of demand.  
• Proactive supply creation: Council-led habitat banking may be necessary to ensure sufficient local supply of biodiversity units.  
• Early assessment: high-level needs analysis, even if desk-based, provides valuable evidence for examination and implementation planning.  
• Developer expectations: expect resistance from development industry on grounds of policy duplication, requiring robust justification.
• Cross-boundary complexity: multi-authority Local Nature Recovery Strategy (LNRS) arrangements and National Character Area boundaries create additional complications requiring local policy clarity.  
• Local benefit principle: the principle that development in a location should deliver biodiversity benefits to that location should be accepted and promoted.