BNG Monitoring Fee Calculator (LPA-Aligned Method)
A BNG monitoring fee calculator is essential for producing a clear, defensible estimate of the monitoring costs that the local planning authority (LPA) will recover over the statutory 30-year management period. These fees, usually secured through a section 106 monitoring fee, cover the council’s work to review your Habitat Management and Monitoring Plan (HMMP), check compliance against commitments, and carry out periodic site inspections.
Where an LPA provides its own calculator, ACP uses it directly. If no local tool is available, we follow a transparent, best-practice approach referencing other councils’ published calculators including North Yorkshire Council and Rushmoor Borough Council which are among the most detailed and widely adopted models. This ensures your BNG monitoring charges are evidence-based, auditable and realistic for budgeting. Our method links your biodiversity net gain plan and HMMP clearly to the monitoring obligations, helping you demonstrate long-term compliance and readiness for legal agreement.
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.
01
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.
02
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.
03
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 councils can charge – the S106 basis and guardrails
Government guidance confirms that local planning authorities (LPAs) are entitled to recover the costs of monitoring planning obligations through a section 106 monitoring fee. In the case of biodiversity net gain (BNG), this fee reflects the resources required to monitor delivery of habitats and ensure compliance with the biodiversity net gain plan and the associated Habitat Management and Monitoring Plan (HMMP) over the full 30-year management period.
The rules are clear: monitoring fees must be justified, proportionate and linked directly to the cost of monitoring the obligation. They cannot be charged retrospectively, and they should not exceed what the council reasonably expects to spend on officer time, reporting, site checks or legal administration. This principle ensures that BNG monitoring charges are treated as cost-recovery, not revenue-raising.
In practice, approaches vary widely. Some councils publish a banded LPA monitoring fee, setting fixed costs according to site size or habitat complexity. Others issue a detailed BNG monitoring fee calculator (often in Excel) that estimates officer time based on habitat mix, reporting cadence and site access.
ACP helps clients navigate these variations by always starting with the host LPA’s published tool. Where none exists, we adopt best-practice comparators (e.g. North Yorkshire and Rushmoor Borough Council calculators) so your monitoring costs remain credible, transparent and easy for planners to audit.
Benchmark calculators we use when the LPA has no tool
Our first step is always to check whether the host local planning authority (LPA) has its own published BNG monitoring fee calculator or a preferred external model. If such a tool exists, we use it directly to ensure alignment with local expectations. Where no local method is available, ACP applies a transparent, evidence-led approach based on recognised best practice. We make it clear in reports that figures are indicative only and must be confirmed with the LPA before agreement.
North Yorkshire Council – full-cost recovery spreadsheet
North Yorkshire has developed one of the most detailed monitoring fee calculators currently available. It adopts a full-cost recovery approach, linking officer hours and rates to reporting years, site checks and internal reporting tasks. The spreadsheet is reviewed annually to keep pace with inflation and pay scales. This model is widely regarded as a best-practice benchmark, particularly because it explicitly ties calculations to the 30-year BNG monitoring obligation.
Key features include:
- Transparent structure (officer hours × rates for reporting and non-reporting years).
- Clear linkage to the statutory 30-year management period.
Policy notes confirming it will be reviewed and updated.
North Northamptonshire Council – size and technical difficulty model
North Northamptonshire’s published Appendix C Monitoring Fee Calculation uses a matrix approach, where fees are based on site size and technical difficulty of habitats, as defined in the statutory metric. This method provides a practical cross-check and is easy to apply to simple or complex schemes alike.
Our step-by-step BNG monitoring fee method (calculator logic)
We set out our methodology clearly in every submission so planning officers can trace each figure back to a published tool or evidence base. If the LPA has its own BNG monitoring fee calculator, we use it directly and show the inputs. If no local method exists, we apply a Best Available Technique approach, drawing on benchmark tools from North Yorkshire and Rushmoor Borough Council.
Step 1: Confirm the securing route and scope
The first step is to confirm how biodiversity net gain will be secured. Where delivery is tied to a section 106 agreement, the LPA will recover costs through a section 106 monitoring fee. In some cases, BNG is secured by condition or conservation covenant; here, monitoring expectations may differ. We make the securing route explicit in our reports.
We also define the scope of work for the full 30-year management period: reviewing Habitat Management and Monitoring Plan (HMMP) reports, checking habitat data against the statutory metric, logging information on council systems, responding to queries, and where agreed conducting periodic site visits.
Step 2: Inputs (what drives the BNG cost)
The BNG monitoring cost is driven by measurable project inputs. These include:
- Habitat scale & mix – the total area/length and type of habitats created or enhanced.
- Technical difficulty – complexity factors from the statutory metric (e.g. wetlands or woodland edges attract higher effort than amenity grassland).
- Reporting cadence – annual monitoring reports vs. less frequent cycles.
- Site access – the likelihood of scheduled LPA monitoring fee site checks in key years (e.g. 1, 5, 10, 20, 30).
- Change risk – factors such as phased developments, land ownership changes or reliance on off-site units, which may increase officer time.
- Indexation & discounting – adjusting for inflation and applying a present-value factor if the LPA prefers a single up-front payment covering 30 years.
Step 3: Time profiles (reporting vs non-reporting years)
We prepare a time-and-tasks matrix that distinguishes between reporting years (full HMMP review, data entry, correspondence, possible site visit) and non-reporting years (spot checks or desk-based updates). Where the host council has defined timings in its calculator, we follow them exactly. If not, we base assumptions on best-practice comparators and clearly state that figures are indicative pending LPA confirmation.
Step 4: Costing assumptions
We align all assumptions with published tools or council rates:
- Officer hourly rates (ecology, planning, legal, admin) based on benchmark spreadsheets or the host authority’s schedule.
- Travel and site visit time, applied sparingly and only in pre-agreed years.
- Internal reporting time to maintain BNG records and contribute to national returns.
By setting out these assumptions transparently, we make it easy for the LPA to check and agree the figures.
Step 5: Calculation engine and outputs
Finally, we present the results in a clear table showing:
- Base hours × rates in reporting and non-reporting years.
- Uplifts for complexity, habitat scale and phasing.
- The present-value factor if an up-front fee is proposed.
- The resulting BNG monitoring charges (or range), expressed as the indicative LPA monitoring fee to be secured through S106.
Where the host council provides its own tool (e.g. North Yorkshire’s Excel model), we include the completed sheet as an appendix and lock our narrative to its outputs. Where only banded fees are published, we show how your project maps to the relevant category. In both cases, the methodology remains auditable and easy for planners and solicitors to follow.
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!
Transparency in our calculations
BNG monitoring is still a new requirement, with mandatory 10% net gain only introduced in 2024. Many local authorities are still developing their own methodologies, fee schedules or BNG monitoring fee calculators, and in some cases no information is available on the public planning portal. In these situations, ACP makes it clear to clients and LPAs how costs have been derived. Where the host authority has no published tool, we apply best practice from other councils for example, the calculators issued by North Yorkshire and Rushmoor Borough Council. This approach ensures your BNG monitoring cost remains credible, auditable and realistic, while keeping your biodiversity net gain plan and HMMP on track for approval.
How this links to your biodiversity net gain plan and HMMP
Your biodiversity net gain plan sets out the scope of habitats to be delivered and the initial commitments that the local planning authority (LPA) must track. This information habitat types, scale, and likely reporting cadence forms the baseline for estimating long-term monitoring requirements. The statutory obligation is for at least 30 years of management and reporting, and councils need clarity on how often they will be asked to check compliance.
The detail comes through in your Habitat Management and Monitoring Plan (HMMP), which specifies who is responsible for reporting, when reports are submitted, and the KPIs used to measure progress. That schedule directly drives the HMMP monitoring fee assumptions and defines the workload the LPA expects to resource. From this, the authority derives its own LPA monitoring fee to be secured via section 106.
ACP’s BNG monitoring fee calculator assessment makes the link explicit: it converts your BNG Plan and HMMP into a clear, justified set of BNG monitoring charges. Presented in a transparent format, this gives planning officers and legal teams confidence that the monitoring costs are proportionate, evidence-based, and ready for inclusion in the agreement.
Deliverables & formats
When you commission ACP to prepare a BNG monitoring fee estimate, you receive a planner-ready compliance pack designed to reduce risk and speed up validation. Each deliverable is structured to support both planning officers and legal teams, giving them the evidence they need in a format they trust.
BNG Monitoring Fee Estimate (PDF)
A clear summary of method, assumptions and results including any ranges that explains how the BNG monitoring cost has been calculated. This makes the figures transparent and auditable.
Completed council calculator (if available)
Where an LPA has its own BNG monitoring fee calculator (such as North Yorkshire, Rushmoor or North Northamptonshire), we complete the sheet directly so the case officer sees their preferred format.
Comparison appendix
A concise comparison of benchmark calculators used (e.g. North Yorkshire and Rushmoor Borough Council), showing how your BNG monitoring charges have been triangulated against best practice.
S106 paragraph suggestions
Draft wording to help legal teams frame the section 106 monitoring fee clause, including indexation notes and payment timing.
Update protocol
Clear advice on what to do if the LPA publishes new guidance mid-application, so you avoid rework and disputes.
Deliverables at a glance
Deliverable | Inclusions | Benefit |
BNG Monitoring Fee Estimate (PDF) | Inputs, assumptions, result + ranges | Transparent & auditable |
LPA Calculator | Completed sheet(s) where available | Fast acceptance by council |
Benchmark Appendix | North Yorkshire, Rushmoor or relevant refs | Credible best-practice basis |
S106 Notes | Monitoring fee & indexation wording | Smoother legal drafting |
Update Protocol | When/why to refresh numbers | Avoids rework & disputes |
Timelines & costs
ACP can usually prepare an LPA-aligned BNG monitoring fee estimate in 3–5 working days once we have your biodiversity net gain plan, draft Habitat Management and Monitoring Plan (HMMP), and habitat schedule. This ensures you have the evidence ready for validation without unnecessary delay.
Our professional fees for preparing a monitoring fee estimate start from £399 + VAT for straightforward, single-phase schemes. The final cost depends on several factors, including:
- The scale and mix of habitats in your BNG Plan.
- The technical difficulty of habitats, which affects the HMMP reporting profile.
- Whether the LPA has its own BNG monitoring fee calculator or requires a benchmarked approach.
- The level of supporting documentation needed (e.g. comparison appendix, completed calculators, S106 drafting notes).
- Multi-phase or multi-parcel projects, which may require milestone delivery.
It’s important to note that this is ACP’s fee for preparing the BNG monitoring fee estimate. The LPA monitoring fee itself secured through a section 106 monitoring fee is calculated separately and must be agreed directly with the council.
Why choose ACP
Evidence-led
ACP bases every BNG monitoring fee estimate on published council calculators or nationally recognised benchmarks. We never rely on arbitrary percentages. By referencing tools such as North Yorkshire or Rushmoor Borough Council models, our method is transparent, credible and easy for planners to audit.
LPA-friendly
We can also present your BNG monitoring charges in the exact format if requested by the local planning authority. Sometimes, LPA may request a completed BNG monitoring fee calculator, a fixed schedule, or a bespoke appendix. A clear narrative is included so that planning and legal officers can follow every assumption without confusion.
Joined-up approach
Our fee estimates are fully integrated with your biodiversity net gain plan and Habitat Management and Monitoring Plan (HMMP). This means the HMMP monitoring fee assumptions and the section 106 monitoring fee wording all line up, avoiding discrepancies that could delay sign-off.
Future-proofed
BNG monitoring is still a new area, and councils are refining their approaches. ACP’s deliverables explain how and when fees should be reviewed or indexed in line with council updates. This protects your project from rework and gives you a defensible basis if methods evolve before your decision notice or legal agreement.
Frequently Asked Questions (FAQs) About the BNG Monitoring Fee Calculator
Understanding how BNG monitoring fees are calculated is vital for budgeting and demonstrating long-term compliance. Local planning authorities and responsible bodies often require developers to commit to monitoring biodiversity outcomes for up to 30 years, but the cost structure can vary widely. This FAQ section explains how ACP’s BNG Monitoring Fee Calculator works, what factors influence monitoring costs, and how fees relate to Habitat Management and Monitoring Plans (HMMPs) and Biodiversity Gain Site registration. Whether you’re a developer, planner, or landowner, these answers clarify how monitoring fees are estimated, what’s included, and how to ensure your BNG obligations remain financially and technically sound over the full management period.
What is a BNG monitoring fee and who decides it?
A BNG monitoring fee is a charge made by the local planning authority (LPA) to recover the cost of monitoring biodiversity net gain compliance over the full 30-year management period. It is normally secured through a section 106 monitoring fee, linked to the obligation that secures your biodiversity net gain plan and HMMP. The fee is set by the council, not the applicant or consultant, and must be proportionate to the work involved. Typical tasks include reviewing monitoring reports, maintaining databases, occasional site visits, and reporting to committee or government. The exact figure depends on whether the LPA uses a published BNG monitoring fee calculator or applies a fixed banded fee schedule.
What if the council doesn’t have its own calculator?
Many LPAs are still developing their approaches, and not all have a published BNG monitoring fee calculator. If no local tool exists, ACP applies a best-practice approach based on models published by other authorities, such as North Yorkshire Council and Rushmoor Borough Council. These calculators are widely regarded as robust and transparent. In our reports we make clear which benchmark has been used, and we label all outputs as indicative pending LPA confirmation. This way, the planning officer has a credible figure to work with, while recognising that the final LPA monitoring fee must be confirmed through the legal process.
Is there a national calculator?
At present, there is no single national BNG monitoring fee calculator mandated by government. Councils are responsible for setting their own monitoring fee policies, provided they are proportionate and cost-based. Some have developed detailed calculators (e.g. North Yorkshire), others publish fixed banded charges (e.g. by site size or habitat area), while independent providers like Verna also offer free online models. ACP references these transparently, but always defaults to the host LPA’s tool if one is available. Until national guidance is standardised, this mixed approach is the reality developers must plan for.
What inputs drive the BNG monitoring cost?
The BNG monitoring cost is influenced by several key factors:
- Habitat scale and mix – larger or more complex habitat portfolios require more officer time to monitor.
- Technical difficulty – habitats such as wetlands or woodland edge are more complex to track than amenity grassland.
- Reporting cadence – annual monitoring reports generate more work than biennial or 5-year cycles.
- Site access and inspections – some LPAs build in costs for scheduled site visits in years 1, 5, 10, 20 and 30.
- Change risk – phased schemes, landownership changes or off-site delivery can all increase monitoring needs.
- Indexation and discounting – a single up-front section 106 monitoring fee often requires future costs to be translated into present value.
ACP builds these inputs into each BNG monitoring fee estimate, ensuring the results are realistic and evidence-based.
How do monitoring fees interact with the HMMP?
Your Habitat Management and Monitoring Plan (HMMP) sets the reporting cadence, responsibilities and KPIs that define how habitats are tracked for 30 years. This directly influences the LPA’s workload and therefore the HMMP monitoring fee assumptions in our calculator. For example, if the HMMP requires annual reporting with species surveys, the LPA’s monitoring time (and therefore fee) will be higher than for a plan with biennial reporting. ACP makes this link explicit: our BNG monitoring fee estimates show how your BNG Plan and HMMP combine to create the time profile that underpins the council’s LPA monitoring fee.
Can the fee be paid once up-front?
Many councils prefer a single up-front section 106 monitoring fee, calculated as the present value of 30 years of monitoring. Others allow phased payments aligned to milestones. Indexation clauses are also common, so that payments reflect inflation over time. ACP clarifies the LPA’s policy at the start of each project. If no local tool exists, we apply best-practice assumptions to model both a lump sum and phased alternative, giving legal teams options for negotiation. This ensures the developer understands the likely BNG monitoring charges before entering into a binding agreement.
Are there fixed LPA monitoring fee schedules?
Yes. Some LPAs publish a fixed LPA monitoring fee schedule, typically banded by site size, number of habitats or technical complexity. For example, a small site with a simple grassland HMMP might be assigned a flat £X, while larger or more complex schemes fall into higher bands. Other councils use calculators that estimate officer time on a case-by-case basis. ACP always maps your project to the host council’s published approach, and where none exists, we use recognised comparators such as North Yorkshire or Rushmoor Borough Council to generate a transparent BNG monitoring fee estimate.
What happens if the LPA releases a new calculator mid-application?
BNG monitoring is a new and evolving field. It’s not uncommon for councils to release or update their BNG monitoring fee calculators during the lifetime of an application. In these cases ACP refreshes the estimate and issues an updated BNG monitoring fee note so that your submission remains aligned with the host authority’s current method. We also include a protocol in our deliverables explaining how and when updates should be applied, minimising the risk of rework or disputes at the legal drafting stage.
How does this relate to other planning obligation fees?
BNG monitoring fees are distinct from generic section 106 monitoring fees that cover other planning obligations such as affordable housing or transport contributions. The BNG monitoring fee is biodiversity-specific and should be calculated only against the council’s workload in checking the BNG Plan and HMMP over 30 years. ACP makes this distinction clear in our reports, ensuring your BNG monitoring charges are proportionate, defensible, and not double-counted alongside wider S106 monitoring fees.
Can ACP talk to the council on my behalf?
Yes. We can approach the ecology or planning team to confirm which BNG monitoring fee calculator to use, or to clarify whether a draft tool is about to be adopted. This prevents clients from being surprised by last-minute fee changes and ensures the final BNG monitoring fee estimate is acceptable to both the developer and the LPA. Our proactive engagement helps avoid delays at validation and provides legal teams with greater certainty when drafting agreements.
Government Guidance and Statutory References
- Understanding biodiversity net gain. Guidance on what BNG is and how it affects land managers, developers and local planning authorities. Defra.
- 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.
- Statutory Biodiversity metric user guide.
- Small Site Matric Guidance.
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.
- North Northamptonshire Council – Monitoring Fee Calculation (Appendix C, PDF)
- Rushmoor Borough Council – BNG Monitoring Fee Calculator (Excel tool)
- Blackburn with Darwen Council – BNG Monitoring Fee Calculator (PDF)
- UK – Biodiversity Metric: Calculate the biodiversity net gain of a project
- North Yorkshire Council – BNG Monitoring and Reporting Fees (decision report, PDF)
- North Yorkshire Council – Biodiversity Net Gain Guidance (webpage)
Recent Google Reviews
Next Steps
- Send us your BNG Plan & HMMP – we extract the reporting cadence and habitat schedule.
- Tell us the host LPA – we’ll check whether a BNG monitoring fee calculator is available.
- Receive a fixed-fee proposal – a simple BNG monitoring fee estimate for single sites, or a milestone plan for complex schemes.
- Draft estimate issued – fully LPA-aligned, with working shown and section 106 monitoring fee wording suggestions.
- Optional support – we liaise with the council and refresh the estimate if a new calculator is issued pre-decision.
Ready to secure a credible BNG monitoring fee estimate? Contact ACP for an LPA-aligned calculation you can submit with your biodiversity net gain plan.
Explore Related Biodiversity Net Gain Resources
Accurately forecasting monitoring costs is essential for long-term Biodiversity Net Gain (BNG) delivery. To understand how monitoring fits within the wider process, start with the Biodiversity Net Gain Overview and BNG Assessment Guide, which explain how post-development habitats are measured and managed.
See how biodiversity units are calculated through the Statutory Biodiversity Metric 4.0 or Small Sites Metric (SSM). Our Biodiversity Gain Plan (BGP) and Habitat Management and Monitoring Plan (HMMP) templates show how to document these costs and responsibilities clearly.
Developers can also view BNG Costs & Pricing for baseline budgeting, or explore Off-Site Biodiversity Units and Registering a Gain Site to secure long-term habitat delivery. For compliance and verification, review BNG Legislation & Guidance and see examples of monitoring implementation in our BNG Case Studies & Portfolio.
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:
- October 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.