Biodiversity Net Gain Consultant | BNG Consultants for Planning
Planning a development project? Ensuring compliance with mandatory biodiversity net gain regulations is crucial for gaining planning permission. At ACP, we provide comprehensive Biodiversity Net Gain (BNG) assessments, surveys and reports that meet the latest planning requirements. Our team ensures that your project enhances natural habitats, aligns with mandatory BNG principles, and helps you achieve biodiversity net gain. We also ensure that your project complies with pre-development and post-development requirements. Trust ACP to help you gain planning permissions while delivering measurable biodiversity improvements.
You can also drop us an email at hello@acp-consultants.com and we’ll get back to you within 24 hours to help with your inquiry!
We follow a simple, transparent process to ensure your project runs smoothly from the very first contact to the final report. Our approach is designed to provide you with clarity at every step, so you’re fully informed and confident in moving forward.
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Step 1: Request a Quote
Fill out our quick quote form or call us, and our team will provide a free, no-obligation quote, outlining the services tailored to your needs.
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Step 2: Confirm Your Booking
Once you approve the quote, simply return the booking form. We’ll schedule your survey and ensure all the details are taken care of.
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Step 3: Receive Your Report
After your survey is completed and payment is received, we’ll promptly issue your survey report, ensuring you get the results as quickly as possible.
What is Biodiversity Net Gain (BNG)?
Biodiversity Net Gain (BNG) is a statutory requirement in England, introduced by the Environment Act 2021, that ensures new developments leave nature in a better state than before. It requires a minimum of 10% measurable improvement in biodiversity value, calculated using the Statutory Biodiversity Metric (SBM), and habitats must be secured and managed for at least 30 years.
BNG is not simply another planning condition. It represents a shift towards environmental sustainability, embedding ecological restoration into development practice. By requiring measurable ecological benefits, BNG supports ecosystem services, improves climate resilience, and strengthens the UK’s natural capital. It also aligns with global sustainable development goals (SDGs) and promotes better long-term land management.
At ACP Consultants, we help developers, planners and landowners understand and achieve BNG. Our role is to translate complex regulations into practical solutions, delivering everything from initial surveys and metric calculations through to Biodiversity Gain Plans (BGPs), Habitat Management and Monitoring Plans (HMMPs), and long-term compliance monitoring.
Achieving BNG is now a fundamental requirement for planning and development projects. This approach to development ensures that projects aim to leave the environment in a measurably better state, enhancing natural habitats. As required by the Environment Act 2021 and Schedule 7A of the Town and Country Planning Act 1990, all developments need achieve at least a 10% improvement in biodiversity. At ACP Consultants Ltd., we help you calculate biodiversity net gain, ensuring your project meets all planning requirements for a biodiversity gain site.
Who Does Biodiversity Net Gain (BNG) Apply To and When?
BNG became mandatory on two key dates:
- 12 February 2024 – for all major developments (residential sites of 10+ dwellings, >0.5 hectares, or commercial schemes >1,000 m²).
- 2 April 2024 – for small sites, including smaller housing and commercial developments.
Not every scheme is covered. BNG exemptions apply to householder applications such as extensions and loft conversions, certain brownfield redevelopments, urgent developments under permitted orders, and schemes impacting irreplaceable habitats such as ancient woodland, veteran trees, blanket bog or peatland. These cases require bespoke compensation rather than the standard metric route.
BNG currently applies only in England, but discussions are ongoing in Wales and Scotland about introducing similar systems. Developers working across the UK should track policy divergence to remain compliant.
Why BNG Matters for Developers and Planners
For developers, BNG is now a core element of planning risk management. Applications can be refused or delayed if they lack the correct documentation. By addressing BNG early, projects avoid costly redesigns or late-stage conditions.
Beyond compliance, BNG delivers wider benefits:
- Stronger placemaking – Green infrastructure such as parks, ponds and tree corridors increases property value and community satisfaction.
- Future-proofed assets – Investors increasingly demand evidence of environmental compliance and climate adaptation. BNG strengthens ESG reporting.
- Community and health outcomes – Accessible green space contributes to wellbeing, while wildlife corridors and habitat connectivity improve local ecology.
- Stakeholder engagement – Local communities, councils and conservation bodies are more supportive when biodiversity is demonstrably enhanced.
In short, BNG reduces planning risk, enhances development value, and supports sustainable, climate-resilient design
As of 12 February 2024, developers must ensure that biodiversity improvements last at least 30 years through legal agreements such as conservation covenants. These agreements help ensure the protection of existing habitats on and off-site. If biodiversity cannot be enhanced within the red line boundary of the site, developers can work with land managers or opt to buy statutory biodiversity credits.
How Biodiversity Net Gain (BNG) is Measured
BNG is measured using official government tools: the Statutory Biodiversity Metric (SBM) and, for qualifying minor schemes, the Small Sites Metric (SSM). Updated user guides published in July 2025 clarified competency requirements, scoring rules, and evidence standards. Further details are presented below.
Statutory Biodiversity Metric (SBM)
The SBM is the standard tool for most developments. It evaluates:
- Area habitats (grasslands, woodland, scrub).
- Linear habitats (hedgerows, tree lines).
- Watercourses (rivers, streams, canals).
Each habitat is assigned a value based on distinctiveness, condition, strategic significance, and multipliers for risk and time. Where watercourse units are included, a River Condition Assessment (RCA) is normally required.
Small Sites Metric (SSM)
The SSM is a simplified calculator for eligible small schemes. It excludes priority habitats and watercourses, and is limited to relatively straightforward sites. The July 2025 update confirmed eligibility rules, clarified how to treat gardens and canals, and emphasised the need for assessor competency.
The planning process for development projects that impact priority habitats need to follow UK regulations, as it applies to England. The UK government has made mandatory biodiversity net requirements integral to the planning system. Particularly for major development and nationally significant infrastructure projects. The Secretary of State plays a key role in overseeing compliance with these standards. This ensures that nature conservation goals are met and that biodiversity is protected across development in England.
Comparative Snapshot of Biodiversity Net Gain Process
- SBM is comprehensive, covering all habitat types, including watercourses and irreplaceable habitats.
- SSM is faster and less data-intensive, but only valid for a narrow range of sites.
- Where in doubt, LPAs usually expect applicants to use SBM.
The Delivery Hierarchy: On-site, Off-site and Credits
One of the most important principles of biodiversity net gain planning is the delivery hierarchy. Local planning authorities and government guidance emphasise that developers should prioritise on-site solutions wherever possible, before looking at off-site options or statutory credits. This tiered approach ensures that ecological improvements are genuine, locally relevant and long-lasting, rather than treated as a transactional afterthought. It also reflects the wider policy drive to restore ecosystem services, improve climate resilience and strengthen the UK’s natural capital.
On-site Biodiversity Net Gain (BNG) delivery
On-site delivery is the preferred option because it integrates biodiversity directly into the development footprint. This may include:
- Creating or enhancing habitats such as meadows, wetlands, ponds, hedgerows and woodland blocks.
- Installing green infrastructure features like green roofs, living walls and wildlife-friendly drainage (SuDS).
- Designing wildlife corridors to connect habitats and reduce fragmentation.
- Incorporating long-term management measures secured through a Habitat Management and Monitoring Plan (HMMP).
On-site solutions often provide wider co-benefits, such as improved air quality, shading, flood mitigation and recreational value. They also demonstrate visible commitment to sustainable development goals and can help win local community and stakeholder support.
Off-site Biodiversity Net Gain (BNG) delivery
If a project cannot achieve the required 10% biodiversity net gain within its red line boundary, developers may purchase or allocate biodiversity units from a registered biodiversity gain site. This process is sometimes referred to as biodiversity offsetting, though under the statutory regime it is more tightly controlled.
Off-site delivery allows gains to be provided in strategic locations, for example:
- Larger habitat banks in rural areas that deliver landscape-scale connectivity.
- Projects aligned with local Biodiversity Action Plans (BAPs) or Local Nature Recovery Strategies.
- Specialist habitats (e.g., wetlands or ancient woodland buffers) that cannot be created effectively on constrained development plots.
LPAs will usually expect evidence that on-site options were fully explored before off-site units are proposed. Developers must also provide legal security through a section 106 agreement or conservation covenant and register the allocation formally.
Developers need to submit a biodiversity gain plan to the local planning authority, which includes these metric calculations, showing how the development will achieve the required net gains.
The strategic significance of a site also plays a role in determining biodiversity net gain. If a site is located in an area that is important for biodiversity conservation, it may score higher in the metric tool, meaning the developer will need to make greater efforts to enhance or protect those habitats.
Statutory credits
Statutory biodiversity net gain credits are a last-resort option. They are purchased directly from government and are deliberately priced at a premium to encourage on-site and local off-site solutions first. Credits are centrally controlled, meaning they do not necessarily deliver benefits in the same locality as the impacted site.
While credits provide a safety net for developments with unavoidable residual impacts, they should not be relied upon as a primary strategy. Excessive reliance may be viewed negatively by LPAs and stakeholders, as it reduces local ecological benefits. Credits should therefore only be used to address gaps that cannot be filled through habitat creation or registered unit purchase.
Assessing the Need for Statutory Biodiversity Net Gain Credits
For developers, the first step is conducting a baseline biodiversity survey of the development site. This survey will assess the current biodiversity value of the site using the statutory biodiversity metric. Based on these findings, developers can create a biodiversity gain plan that outlines how they will enhance the biodiversity value of the site.
Once the plan is submitted, the local planning authority will review it alongside the planning application. If the development is expected to result in a measurable biodiversity net gain, the planning authority should grant permission. In cases where developers cannot meet the required gains on-site, they may need to explore off-site options or purchase biodiversity credits.
In cases where on-site biodiversity gains are not feasible, developers should work with land managers or buy statutory biodiversity credits. These credits can be used to enhance biodiversity at existing or off-site locations. In some instances, developers may need to work with the government, as the government will use the revenue generated by credits to fund biodiversity improvement projects elsewhere.
Example Scenarios
- Suburban housing estate in Surrey: Achieved over 12% net gain entirely on-site through wildflower meadows, hedgerow planting and woodland creation. This approach maximised ecological connectivity while also boosting community amenity space.
- City-centre mixed-use development in London: With limited space available, the project combined rooftop green infrastructure and tree planting with the purchase of off-site units from a nearby habitat bank. This hybrid approach balanced urban density with ecological responsibility.
- Major road scheme in the Midlands: Large infrastructure projects often have significant, unavoidable biodiversity impacts. In this case, the developer created on-site woodland and grassland, allocated units from a regional habitat bank, and purchased statutory credits to cover residual losses.
Developers need to demonstrate pre-development and post-development biodiversity improvements and outline how they will maintain biodiversity gain sites to meet the mandatory biodiversity net gain requirements. These obligations include maintaining and improving existing habitats, whether on-site or through off-site solutions. For small sites from 2 April 2024, the same standards apply, and local planning authorities will assess the planning permissions granted to ensure projects meet the required biodiversity standards.
What You Must Submit
Meeting BNG requirements is not just about design intent — it is about evidencing compliance in a structured way that satisfies both the planning authority and statutory regulations. Local Planning Authorities (LPAs) require a series of formal submissions that demonstrate how the 10% biodiversity net gain target will be achieved, how habitats will be managed long-term, and how gains are legally secured.
ACP Consultants specialises in preparing these documents. While we do not personally create or manage habitats on the ground, we provide the expert BNG assessments, calculations and plans that form the foundation of a successful application.
Biodiversity Gain Plan (BGP)
The Biodiversity Gain Plan is the core statutory document proving how your project will deliver net gain. It must be completed using the official government template and is typically submitted after planning permission is granted but before construction starts.
A BGP demonstrates that a scheme has fully addressed the delivery hierarchy (on-site first, then off-site, then credits if necessary). It provides transparency for the LPA, Natural England, and stakeholders, ensuring that biodiversity improvements are measurable, enforceable and legally secured.
The template requires:
- Baseline habitat survey results (in UKHab format) to show the site’s ecological starting point.
- Metric outputs (from SBM or SSM) evidencing calculations of units lost and gained.
- Proposed habitat enhancements and design measures, aligned with local biodiversity priorities.
- Legal security information, usually through a section 106 agreement or conservation covenant, guaranteeing 30-year delivery.
- Long-term monitoring commitments, typically secured via an HMMP.
ACP Consultants can prepare and complete BGPs on your behalf, making sure the content aligns with statutory requirements and local validation lists. We ensure that every figure is supported by evidence, reducing the risk of LPA rejection or costly redesigns.
Habitat Management & Monitoring Plan (HMMP)
The HMMP is a critical companion document to the BGP. While the BGP explains what will be delivered, the HMMP sets out how those habitats will be maintained and improved for at least 30 years. Without a credible HMMP, LPAs may consider a submission incomplete.
An HMMP typically includes:
- Clear management objectives – what the habitat should look like in 10, 20, and 30 years.
- Prescriptions and management actions – mowing regimes, planting, invasive species control, wetland maintenance.
- Monitoring schedules – annual inspections, photographic records, ecological monitoring surveys.
- Key Performance Indicators (KPIs) – measurable outcomes such as canopy cover, species richness or condition scores.
- Reporting arrangements – who submits evidence to the LPA and at what intervals.
ACP Consultants can prepare HMMPs that align with government templates and local expectations. While we do not carry out the physical land management, we ensure that your HMMP provides a realistic, costed and regulator-ready framework that developers and land managers can follow confidently.
Registering an Off-Site Gain Site
Where a development cannot deliver the required 10% gain on-site, off-site units may be used. These must come from a registered biodiversity gain site. The register is maintained nationally and ensures that off-site units are legitimate, measurable and legally secured.
Registration requires:
- Proof of site ownership or control.
- Baseline data showing existing habitats and condition.
- Details of proposed enhancements including habitat type, target condition and delivery timeline.
- Legal security via a conservation covenant or section 106 agreement.
- Payment of the current registration fee (£639).
Monitoring Fees
Local Planning Authorities (LPAs) are permitted to charge monitoring fees to cover the cost of overseeing BNG commitments over the 30-year period. These charges help fund the review of annual monitoring reports, site inspections, and compliance checks to ensure that habitats continue to meet the outcomes set out in the Habitat Management and Monitoring Plan (HMMP).
At present, only a small number of councils, such as North Yorkshire and Rushmoor, have published their own BNG monitoring fee calculators or schedules. These tools allow applicants to estimate potential costs, often based on habitat type, site size, and management complexity. However, there is no national standard yet, and many LPAs are still developing their approach. This creates variation between authorities and some uncertainty for applicants.
In the absence of a council-specific tool, ACP Consultants guides clients using best available practice and emerging methodologies. We draw on published examples, industry benchmarks, and discussions with LPAs to help project teams estimate likely costs. Where appropriate, we recommend conservative budgeting to avoid unexpected liabilities later in the planning process.
Our role is to ensure clients are fully informed of the potential financial implications of BNG monitoring, to explain the basis of any assumptions, and to support agreement with the LPA. As this is a new and evolving process, we remain flexible, updating our advice as further best available techniques (BAT) and council methodologies are released.
Exemptions and Special Cases
BNG exemptions apply to:
- Householder developments such as small extensions.
- Some brownfield redevelopments where biodiversity is negligible.
- Urgent developments permitted under emergency powers.
- Irreplaceable habitats (ancient woodland, veteran trees, blanket bogs, fens). These do not use the metric approach, but require bespoke mitigation strategies.
Irreplaceable habitats are particularly sensitive. Development here requires high-level mitigation and ecological impact assessment beyond the standard metric.
Our End-to-End Process
ACP delivers a structured, transparent process to ensure projects achieve compliance:
- Initial scoping – Review plans, identify risks, and confirm whether SBM or SSM applies.
- Baseline survey (UKHab) – Detailed habitat mapping and condition assessment.
- Metric calculations – Running SBM/SSM scenarios to test design options.
- Design collaboration – Working with architects and engineers to balance ecology and buildability.
- BGP preparation – Completing the official template with supporting evidence.
- Legal security – Supporting clients with s106 agreements or conservation covenants.
- Register support – Coordinating registration of off-site units.
- HMMP drafting – Producing a compliant 30-year management plan.
- Implementation – Advising contractors on habitat delivery.
- Monitoring – Preparing reports to satisfy LPA conditions over 30 years.
In the past year, we’ve delivered over 750 audit-ready reports supporting 400+ projects for developers, planners, and architects nationwide. We put quality over quantity and build lasting relationships based on trust, ensuring your planning applications are backed by robust evidence and delivered on time.
You can also drop us an email at hello@acp-consultants.com and we’ll get back to you within 24 hours to help with your inquiry!
Timelines and Costs
Understanding the likely timeframes and costs of biodiversity net gain assessments is critical for developers and planners. While every project is unique, there are typical delivery windows for the main components:
- Baseline survey: usually carried out within 1–2 weeks of instruction, although exact timing may depend on the season and survey windows.
- Metric calculations: once survey data is available, the biodiversity net gain metric (SBM or SSM) can be completed within 3–5 working days.
- Biodiversity Gain Plan (BGP) preparation: producing a compliant plan, including supporting evidence, typically takes 1–2 weeks depending on the scheme’s complexity.
- Habitat Management & Monitoring Plan (HMMP) drafting: preparing a detailed 30-year management framework generally takes 2–3 weeks, often in parallel with legal or planning discussions.
These are indicative timescales and may be adjusted if LPAs request additional clarifications or if multiple design iterations are needed.
Costs and budgeting
The cost of meeting BNG requirements depends on a range of factors. This includes site size, baseline habitat condition, and whether gains can be delivered on-site. Applicants must also consider:
- Off-site biodiversity units – market prices vary depending on availability, location, and habitat type.
- Statutory credits – available as a last resort, but deliberately priced at a premium.
- Monitoring fees – charged by LPAs to cover long-term compliance checks, which vary widely across councils.
As BNG is still a relatively new statutory process, there is variation in how councils approach fee structures. Some have published BNG monitoring fee calculators, while others provide indicative schedules or case-by-case assessments. In practice, ACP Consultants guide clients using the best available methods and published benchmarks, helping project teams plan realistic budgets and avoid unexpected liabilities. Where council-specific calculators are not yet available, we advise allowing for a degree of contingency to support long-term compliance.
Biodiversity Net Gain (BNG) by Location: Regional and Council Differences
BNG implementation is consistent in principle across England — every development must demonstrate a 10% biodiversity net gain using the government metric. However, the detail of how LPAs apply these rules varies widely, and this can affect validation, costs, and project timelines.
For example:
- Southwark Council may require developers to submit a Biodiversity Gain Plan (BGP) before or after permission is granted, with detailed Small Sites Metric (SSM) outputs for qualifying schemes. This makes early baseline surveys and metric runs essential.
- Reading Borough Council has published monitoring fee guidance linked to Habitat Management & Monitoring Plans (HMMPs). Developers need to budget for these costs upfront to avoid unexpected liabilities.
- North Yorkshire Council provides one of the most robust BNG monitoring fee calculators, which sets fees based on habitat type, size, and management complexity. This model is already influencing best practice in other regions.
- London boroughs such as Camden and Lambeth expect BNG scoping evidence at pre-application stage, meaning applicants should provide early survey data and outline strategies to demonstrate compliance.
Because of these variations, developers and planning consultants cannot rely on a one-size-fits-all approach. ACP’s BNG by Location hub collates council-specific requirements, links to published fee schedules or calculators, and highlights where emerging practice is being trialled. This ensures applicants remain compliant, avoid delays at validation, and achieve environmental compliance even where local guidance is still evolving.
Biodiversity Net Gain (BNG) Case Studies
Real-world projects show how biodiversity net gain can be achieved across different sectors. While ACP Consultants does not carry out habitat creation directly, we prepare the surveys, metrics and documentation that enable projects to satisfy statutory requirements.
Housing Development, Oxfordshire
A large housing scheme on former agricultural land was required to demonstrate more than the statutory 10% net gain. ACP undertook the baseline biodiversity net gain assessment, prepared the Statutory Biodiversity Metric (SBM), and produced the Biodiversity Gain Plan (BGP). By integrating wildflower meadows, hedgerow networks and new woodland planting into the masterplan, the scheme delivered a 12% net gain. The BGP was accepted first time, helping the client avoid planning delays.
Urban Mixed-Use, London
In dense urban settings, on-site options are limited. For this mixed-use redevelopment, ACP prepared an SSM calculation and guided the design team on feasible on-site measures including green roofs, tree planting and pollinator-friendly landscaping. To reach the full requirement, the client purchased off-site units from a local habitat bank. Long-term compliance was secured through a conservation covenant. This project demonstrates how BNG credits and off-site delivery can complement urban design.
Infrastructure Project, Midlands
Large infrastructure projects often involve significant biodiversity impacts. For this road scheme, ACP carried out River Condition Assessment (RCA) and ditch surveys, ensuring watercourse habitats were properly represented in the metric. The scheme combined extensive on-site woodland creation with allocation of off-site biodiversity units, before purchasing statutory credits to cover unavoidable residual losses. The result was a robust, regulator-approved pathway to compliance, illustrating how the delivery hierarchy functions in practice.
Retail Redevelopment, Northamptonshire
On a smaller brownfield retail site, ACP applied the Small Sites Metric (SSM). Baseline surveys showed limited existing habitats, allowing the scheme to focus on pollinator-friendly landscaping and small-scale green infrastructure. The approach met statutory requirements efficiently, keeping costs proportionate for the client. This case demonstrates how BNG exemptions and simplified metrics apply to smaller developments.
Together, these case studies highlight how ACP adapts its services across housing, commercial, and infrastructure sectors. By preparing the right BNG assessments, plans and monitoring frameworks, we help clients achieve both planning approval and genuine ecological benefit.
Recent Updates: Biodiversity Net Gain (BNG)
BNG guidance is still evolving as local planning authorities and developers adjust to the statutory framework. Several important updates have been published recently that directly affect how applicants prepare biodiversity net gain assessments and supporting documents.
- June 2025 – GOV.UK “Understanding BNG” update: Government guidance was refreshed with clearer explanations of exemptions, including householders, brownfield redevelopments, and irreplaceable habitats. This helps applicants understand whether their projects fall under biodiversity net gain exemptions or require full metric assessments.
- July 2025 – DEFRA user guide updates: The Statutory Biodiversity Metric (SBM) and Small Sites Metric (SSM) user guides were updated with detailed clarifications on eligibility rules, assessor competency, and definitions for habitat types. These changes ensure greater consistency in how calculations are carried out across England.
- Local authority practice – ongoing: More LPAs are beginning to publish their own BNG fee schedules or monitoring fee calculators, creating variation in local costs. This reflects how councils are interpreting biodiversity net gain legislation at the local level.
Because this is a new statutory process, ACP Consultants monitors official updates and local practice on a regular basis and integrates changes into client advice. By staying up to date with evolving guidance, we ensure that every Biodiversity Gain Plan (BGP), Habitat Management and Monitoring Plan (HMMP), or off-site unit strategy we prepare reflects the latest standards and best available techniques (BAT).
Frequently Asked Questions (FAQs) on Key Biodiversity Net Gain (BNG) Requirements
If you’re preparing a biodiversity net gain assessment or need to submit a Biodiversity Gain Plan, it’s natural to have questions. This FAQ section explains the key requirements of the BNG metric, how off-site units and statutory credits work, and what exemptions may apply.
1. What is Biodiversity Net Gain (BNG)?
Biodiversity Net Gain (BNG) is a statutory planning requirement in England. It ensures new developments leave the natural environment in a measurably better state. Developers must deliver at least a 10% improvement in biodiversity value compared to the pre-development baseline. This is evidenced through a formal biodiversity net gain assessment using the government’s metric tools. BNG also requires habitats to be secured and managed for a minimum of 30 years. This is to ensure long-term ecological benefits rather than short-term mitigation.
2. When did Biodiversity Net Gain (BNG) become mandatory?
BNG requirements came into effect on:
- 12 February 2024 – mandatory for all major developments.
- 2 April 2024 – extended to small sites.
This means that almost all new planning applications in England must now consider biodiversity net gain as part of their submission. Some exemptions still apply (see below), but for most developers it has become an integral part of achieving planning permission and environmental compliance.
3. Which metric should I use?
BNG is measured using government-approved tools:
- Statutory Biodiversity Metric (SBM): the default tool for most sites, covering all habitat types including watercourses and hedgerows.
- Small Sites Metric (SSM): a simplified version for eligible smaller schemes, excluding priority habitats and watercourses.
If your site qualifies, the SSM can reduce complexity. However, in many cases LPAs prefer or require the full SBM. ACP Consultants will advise which tool applies during the early biodiversity net gain assessment stage to ensure submissions meet local validation requirements.
4. What is a Biodiversity Gain Plan?
A Biodiversity Gain Plan (BGP) is the formal document that proves how a development will achieve the 10% net gain. It must be completed using the government’s official template and is submitted after planning permission is granted but before development begins.
A BGP usually includes:
- Baseline survey results (UKHab format).
- Metric calculations (SBM or SSM outputs).
- Details of proposed habitat creation or enhancement.
- Long-term management commitments (via HMMP).
- Evidence of legal security, such as a section 106 agreement or conservation covenant.
ACP Consultants prepare compliant BGPs that satisfy both national requirements and local planning authority expectations.
5. What is an HMMP?
The Habitat Management and Monitoring Plan (HMMP) sets out how created or enhanced habitats will be maintained for at least 30 years. It ensures biodiversity net gain is not just theoretical, but actually delivered and sustained on the ground.
An HMMP will include:
- Management objectives (e.g. maintaining grassland in good condition).
- Specific actions (e.g. mowing, planting, invasive species control).
- Monitoring schedules (annual reports, surveys, photographs).
- Key Performance Indicators (KPIs) to measure success.
While developers or land managers implement the HMMP, ACP Consultants provide the specialist documentation and framework required to satisfy the LPA.
6. How do off-site units work?
If a scheme cannot achieve the 10% gain within its own boundary, it may use off-site biodiversity units. These must come from a registered biodiversity gain site. Registration requires baseline data, enhancement proposals, legal security, and payment of the current £639 fee.
This system ensures off-site units are legitimate, properly managed and available for allocation. It supports landscape-scale conservation by directing gains to strategic locations. ACP Consultants advise clients on evidencing off-site delivery and ensuring agreements meet LPA requirements.
7. What is a River Condition Assessment?
A River Condition Assessment (RCA) is a specialist survey required where watercourse habitats are affected. Under the biodiversity net gain metric, watercourses are assessed separately to ensure their condition and ecological function are properly measured.
An RCA involves on-site surveys of flow, morphology, riparian habitat, and ecological quality. Results feed directly into the Statutory Biodiversity Metric, helping to calculate accurate unit losses and gains. ACP Consultants can scope and arrange RCAs where required.
This system ensures off-site units are legitimate, properly managed and available for allocation. It supports landscape-scale conservation by directing gains to strategic locations. ACP Consultants advise clients on evidencing off-site delivery and ensuring agreements meet LPA requirements.
8. Are there exemptions?
Yes, not all developments must deliver BNG. Current biodiversity net gain exemptions include:
- Householder applications (e.g. extensions or loft conversions).
- Certain brownfield redevelopments with negligible biodiversity.
- Urgent developments under permitted orders.
- Projects impacting irreplaceable habitats such as ancient woodland, veteran trees, peatland or blanket bog (where bespoke compensation applies instead).
Because exemptions are limited and subject to interpretation, ACP Consultants always review each case carefully. Where exemptions do not apply, we ensure the correct metric and documentation are used so applications remain valid.
9. What are statutory biodiversity credits?
Statutory biodiversity net gain credits are government-issued units available as a last resort if on-site and off-site options cannot deliver the required 10% gain. They are deliberately priced at a premium to encourage local solutions first. While credits provide flexibility, LPAs will expect clear evidence that other routes were explored before credits are purchased.
10. How are Biodiversity Net Gain (BNG) costs calculated?
BNG costs vary depending on site size, complexity, and whether on-site, off-site or credits are used. Some councils, such as North Yorkshire, have published BNG monitoring fee calculators, but many LPAs are still refining their approach. In the absence of a local tool, ACP Consultants guide clients using the best available methods and benchmarks, ensuring financial planning reflects realistic expectations.
Practical FAQs on BNG Surveys, Reports & Consultancy Services
When it comes to delivering biodiversity net gain (BNG) on your project, it’s natural to have practical questions about surveys, reports, costs, and timelines. This section answers the most common queries about working with BNG consultants, preparing biodiversity net gain reports and gain plans, and arranging BNG surveys with fast delivery from a local consultant. Our aim is to make the process clear and straightforward so you can secure planning approval without delays.
Q1. What does biodiversity net gain planning involve?
Biodiversity net gain planning requires developers to demonstrate at least a 10% net improvement in habitat value. Our BNG consultants prepare biodiversity net gain reports, surveys and biodiversity gain plans that meet local planning authority requirements and statutory legislation.
Q2. How do I use the biodiversity net gain calculator?
The biodiversity net gain calculator (BNG calculator) is a government tool that converts habitat survey data into measurable biodiversity units. Our ecologists complete a full BNG survey, input the results into the biodiversity metric, and provide you with a BNG report or BNG survey PDF for submission.
Q3. Are there biodiversity net gain exemptions?
Yes, some smaller developments may qualify for biodiversity net gain exemptions under current biodiversity net gain legislation and planning practice guidance. Our BNG consultants check eligibility against 2024 BNG regulations and provide clear advice on whether your site needs a biodiversity net gain assessment.
Q4. Can you provide biodiversity net gain examples?
We provide biodiversity net gain examples and case studies to show how a BNG plan or BNG report is structured. These demonstrate the use of the biodiversity net gain calculator, habitat creation measures, and biodiversity unit costs, ensuring your project follows biodiversity net gain guidance UK.
Q5. What is included in a biodiversity net gain report?
A biodiversity net gain report (BNG report) includes your baseline habitat survey, biodiversity metric calculation, biodiversity gain plan, and recommendations for habitat creation or management. Our local BNG consultants offer fast delivery of BNG surveys and reports, tailored to your project size and planning authority.
Q6. How much does a BNG survey cost?
BNG survey cost depends on the size and complexity of your site. Simple sites may only need a baseline habitat survey, while larger developments require a full biodiversity net gain assessment, biodiversity net gain report, and biodiversity gain plan. We provide clear fixed quotes with fast delivery.
Q7. Do I need a biodiversity net gain report for planning applications?
Yes. Since February 2024, biodiversity net gain legislation requires most planning applications in England to include a biodiversity net gain report or BNG report. Our BNG consultants prepare reports in line with biodiversity net gain UK regulations and local authority guidance.
Q8. Where can I find biodiversity net gain guidance?
Official biodiversity net gain guidance is published on GOV.UK, including details on biodiversity net gain surveys, exemptions, and planning practice guidance. Our ecologists translate this guidance into practical steps, providing you with a BNG assessment, biodiversity gain plan, and BNG survey PDF for submission.
Q9. How much do BNG unit costs and habitat creation costs vary?
BNG unit costs and BNG habitat creation costs vary depending on habitat type and location. Purchasing biodiversity credits or off-site units is usually more expensive than delivering on-site gains. Our biodiversity net gain consultants provide detailed costings within your BNG plan and BNG report.
Q10. How do I find a BNG consultant near me?
ACP Consultants provide biodiversity net gain consultants nationwide. If you are searching for a local BNG consultant or ecologist BNG expert, we can deploy a team near you with fast delivery of biodiversity net gain surveys, reports, and gain plans.
Q11. Why should I hire a biodiversity net gain (BNG) consultant?
A biodiversity net gain consultant (BNG consultant) provides expert advice on BNG surveys, biodiversity gain plans, and biodiversity net gain reports. Our consultants ensure your planning application complies with biodiversity net gain legislation 2024, using the biodiversity net gain calculator and the latest government guidance.
Q12. Do I need one or multiple biodiversity net gain reports?
Some projects require more than one biodiversity net gain report (BNG report), for example, an initial baseline BNG survey PDF followed by an updated biodiversity gain plan. Our ecologists prepare biodiversity net gain reports tailored to your project and deliver them with fast turnaround times.
Q13. How quickly can you deliver a BNG survey or BNG report?
We offer fast delivery of BNG surveys, biodiversity gain plans, and biodiversity net gain reports to meet urgent planning deadlines. Our local BNG consultants provide quick site visits and reports, ensuring you avoid planning delays.
Q14. What is the cost of a BNG report compared to a survey?
BNG report cost depends on project size and whether a full biodiversity net gain assessment is required. While a BNG survey cost covers the site visit and baseline data, the BNG report cost includes analysis, the biodiversity metric calculation, and a full biodiversity gain plan.
Q15. How do I choose the right BNG consultant?
When searching online for BNG consultants, you may see different providers offering biodiversity net gain reports. The key is to select a local BNG consultant who can deliver fast, compliant BNG surveys, biodiversity gain plans, and reports tailored to your planning authority. ACP Consultants provide nationwide coverage with expert ecologist BNG specialists.
Government Guidance and Statutory References
- Statutory framework & planning condition. Biodiversity Net Gain under Schedule 7A of the Town and Country Planning Act 1990; statutory regime explained in Planning Practice Guidance (GOV.UK).
- Biodiversity Gain Plan – Must be approved before commencement; Local Planning Authority decision normally within 8 weeks. See Biodiversity Net Gain Guidance (GOV.UK).
- Statutory biodiversity metric – How units are calculated, modules, factors, and guidance on early use. Statutory Metric and User Guide (GOV.UK).
- Condition Sheets & Small Sites Metric (SSM) – Official metric tools and guidance sheets. BNG Metric Tools (GOV.UK).
- Exemptions & de minimis thresholds – Householder, small self-build, and very small impacts where no priority habitat is affected. Exemptions Guidance (GOV.UK) and Defra Environment Blog.
- Off-site register & fee – Natural England guidance on registering biodiversity gain sites, with the current £639 registration fee. Register a Biodiversity Gain Site (GOV.UK).
- NSIPs timing – Government proposals indicate that BNG will apply to Nationally Significant Infrastructure Projects (NSIPs) from May 2026, pending final regulations. Defra Consultation (GOV.UK).
- Creating a Habitat Management & Monitoring Plan (HMMP) – GOV.UK guidance on how to prepare HMMPs, including monitoring and reporting requirements. HMMP Guidance (GOV.UK).
- Natural England HMMP Template (JP058) – Official template, checklist, and monitoring report tools for Habitat Management & Monitoring Plans. Natural England Publications.
- Statutory Biodiversity Metric User Guide (July 2025). Full guidance on how the statutory metric should be applied, including trading rules and worked examples. User Guide PDF.
- Metric Supporting Documents (JP039) – Includes GIS templates, data standards, and case studies for applying the statutory metric. Natural England Publications.
Other Supporting References (Quick Links)
- BNG in Practice Report (2025) – Case studies showing how BNG is being delivered in real projects. Institute of Environmental Sciences.
- Biodiversity Net Gain – Principles and Guidance for UK Construction and Developments. Chartered Institute of Ecology and Environmental Management.
- BNG Research Briefing – This post note outlines the mandatory biodiversity net gain policy introduced in England in 2024 and the risks and challenges for delivering its objectives. UK Parliament.
- Biodiversity net gain: where to start. Natural England.
Why Choose ACP Consultants
Qualified team – Experienced consultants with ecology degrees and specialist training. We’ve been practising BNG since its introduction, keeping pace with every update.
Proven results – Successful BNG submissions across housing, commercial and infrastructure projects nationwide.
Fast turnaround – Surveys delivered in 1–2 weeks, metrics in 3–5 days to keep your project on track.
Nationwide expertise – Direct experience with council requirements across England, from local boroughs to large unitary authorities.
Specialist skills – Accredited training in River Condition Assessments and ditch condition surveys, expertise that many consultancies lack.
Transparent pricing – Clear, upfront quotes with no hidden extras.
Explore All Biodiversity Net Gain Resources
ACP Consultants provides a complete suite of Biodiversity Net Gain (BNG) services, tools, and resources — supporting developers, planners, and landowners from initial surveys through to long-term monitoring and compliance. Explore the full BNG process below and access detailed guides for each stage.
1. Understanding the Framework
Learn the fundamentals of BNG through our BNG Assessment Guide, which explains how habitat value, distinctiveness, and condition are evaluated. Review the legal background under the BNG Legislation & Guidance page, and confirm whether your project qualifies through BNG Exemptions & Thresholds.
2. Calculating Biodiversity Units
Use the Statutory Biodiversity Metric 4.0 or Small Sites Metric (SSM) to quantify ecological change, and understand how river and wetland features are measured in our River Condition Assessment (RCA) and Ditch Condition Assessment (DCA) guidance.
3. Preparing Your BNG Documentation
Access practical templates and examples through BNG Templates & Downloads.
Prepare your Biodiversity Gain Plan (BGP), the central submission document and the accompanying Habitat Management and Monitoring Plan (HMMP), ensuring your strategy meets planning authority expectations.
4. Delivery, Costs & Monitoring
Use our BNG Monitoring Fee Calculator and BNG Costs & Pricing guides to estimate financial commitments. Learn how Off-Site Biodiversity Units and Registering a Gain Site can help achieve compliance where on-site delivery is limited.
5. Legal Security & Long-Term Management
Understand how long-term habitat protection is secured through Conservation Covenants vs Section 106 Agreements and what’s required to maintain sites beyond the minimum 30-year period.
6. Demonstrating Outcomes & Best Practice
See practical examples in our BNG Case Studies & Portfolio, explore real delivery success stories, and consult our BNG FAQs for quick answers to common questions. You can also find regional expertise across BNG Locations and contact our BNG Consultants for tailored advice.
You can also drop us an email at hello@acp-consultants.com and we’ll get back to you within 24 hours to help with your inquiry!
- Last Updated:
- November 2025
Disclaimer: Our content is prepared by ACP Consultants’ in-house specialists and is based on current guidance, standards, and best practice in environmental consultancy. While we make every effort to keep information accurate and up to date, it is provided for general guidance only and should not be relied upon as a substitute for professional advice on specific projects. Planning authorities retain final decision-making powers, and requirements may vary between local authorities and over time. ACP Consultants accepts no liability for any loss arising from reliance on this content without obtaining tailored advice for your project.