Biodiversity Net Gain Survey / BNG Surveys for Planning Applications
A Biodiversity Net Gain Survey (BNG survey) is now a mandatory requirement for most planning applications in England. From February 2024 for major sites, and April 2024 for small sites, all developments must demonstrate at least 10% biodiversity net gain (BNG) under the Environment Act 2021. This is achieved by measuring the site’s existing habitats, calculating their value using statutory ecological metrics, and then showing how the scheme will deliver an uplift through habitat creation, enhancement, or off-site units.
ACP provides professional BNG surveys across England, starting from £399 + VAT. Our ecologists carry out BNG baseline surveys, habitat mapping, and biodiversity net gain assessments, producing evidence that satisfies both national policy and local planning authority (LPA) validation requirements. Whether you’re a developer, planner, architect, landowner, or small site applicant, our surveys give you the baseline data and compliance reporting needed to keep your application moving.
Unlike a standard ecology survey, a BNG survey focuses specifically on habitat condition, distinctiveness, and connectivity. The outputs feed directly into your Biodiversity Net Gain Report, Habitat Management and Monitoring Plan (HMMP), and, where relevant, a River Condition Assessment (RCA). Together, these documents form the BNG submission that planning officers now expect at validation. ACP’s reports are written in plain English for planners, backed by robust ecological data and mapping. They not only demonstrate compliance but also align your project with wider goals such as environmental sustainability, climate change adaptation, and biodiversity conservation.
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 a Biodiversity Net Gain Survey/ BNG survey?
A BNG survey (Biodiversity Net Gain survey) is a structured ecological assessment carried out to establish the existing biodiversity value of a site. Sometimes called a BNG baseline survey or ecology survey for BNG, it is the essential first step in preparing a biodiversity net gain assessment for planning.
The purpose of the survey is to create a clear, measurable record of the site’s habitats before development begins. Using the UKHab classification system, ACP’s ecologists:
- Map all habitats present on site, from grassland and woodland to hedgerows and watercourses.
- Assess habitat condition and distinctiveness, identifying whether habitats are in good, moderate, or poor condition.
- Measure the size of habitats by area (hectares) or length (kilometres for hedgerows and rivers).
- Calculate baseline biodiversity units using the statutory ecological metrics.
The outcome is a baseline biodiversity score against which the development must be measured. To comply with the Environment Act 2021, your scheme must deliver at least a 10% uplift compared with this baseline.
A Biodiversity Net Gain Survey/ BNG survey differs from general ecological surveys such as Preliminary Ecological Appraisals (PEAs). While PEAs look broadly at site constraints and potential for protected species, a BNG survey is focused specifically on habitats and the calculation of biodiversity units. The results feed directly into your Biodiversity Net Gain Report, guide the design of habitat creation measures, and provide the foundation for your Habitat Management and Monitoring Plan (HMMP). Where watercourses are involved, the survey also incorporates a River Condition Assessment (RCA) to capture river and riparian habitat value.
In practice, no development can demonstrate compliance with the 10% requirement without a BNG survey. This is why local planning authorities increasingly require BNG surveys as part of planning submissions.
Why are BNG surveys required?
A BNG survey is now a legal requirement for most development projects in England. Under the Environment Act 2021, all planning applications (except those exempt) must demonstrate at least 10% biodiversity net gain (BNG). Local planning authorities (LPAs) enforce this by requiring developers to submit a BNG survey and supporting documents at validation. Without a survey, the LPA cannot confirm whether the project complies with national policy, and the application is likely to be delayed or refused.
The primary purpose of a BNG survey is to provide a transparent, measurable baseline of the site’s habitats. By mapping, classifying and scoring habitats through ecological metrics, the survey establishes the starting point against which the proposed development will be judged. The post-development design must then deliver at least a 10% uplift in biodiversity units. This approach ensures that all projects leave nature in a measurably better state than before.
Beyond legal compliance, BNG surveys play an important role in planning outcomes. LPAs increasingly expect evidence of biodiversity net gain assessment at both outline and full application stages. Many councils go further, requesting surveys at the pre-application stage to help shape design. Early engagement with ACP’s ecologists ensures your baseline evidence is robust, supports design choices, and reduces the risk of last-minute changes or objections.
BNG surveys also contribute to wider policy objectives, including biodiversity conservation, climate change adaptation, and the creation of green infrastructure. By evidencing how a development supports habitats, wildlife corridors and long-term management, a BNG survey demonstrates not only compliance but also alignment with broader environmental sustainability goals.
In short, a BNG survey is essential because it is both a statutory planning requirement and a practical tool for designing and delivering better developments.
Policy context across England: how LPAs apply BNG in practice
Although BNG surveys are mandated nationally, local planning authorities (LPAs) apply the rules through their own validation requirements, supplementary planning documents (SPDs), and policy notes. This means expectations can vary depending on where your development is located.
London
The London Plan (Policy G6) requires developments to secure biodiversity net gain. Boroughs such as Westminster and Camden expect applications to demonstrate how the 10% target will be achieved. Where on-site delivery is not possible, off-site habitat creation must be evidenced through the BNG submission.
Greater Manchester
Greater Manchester has issued combined authority guidance confirming the 10% requirement from February 2024. Their notes also stress that biodiversity unit calculations must be re-run if site layouts change, to ensure the 10% net gain is maintained.
Nottingham & Nottinghamshire
Nottingham City Council and Nottinghamshire County Council are preparing BNG SPDs, with emerging frameworks signalling a possible 20% aspirational target where feasible. This sits alongside the statutory 10% requirement and reflects local ambitions to go beyond the national minimum.
Warwickshire, Coventry and Solihull
This sub-region has been a national pilot for biodiversity offsetting and requires a 10% increase for both minor and major applications. Local planning officers are highly familiar with the biodiversity metric and expect BNG surveys and reports to be transparent and auditable.
Cornwall
Cornwall Council was one of the earliest adopters of BNG, requiring 10% net gain for major applications before the national rollout. Its validation checklist now includes BNG statements, completed metric workbooks, and clear evidence of how the 10% will be achieved on or off site.
West Midlands highlights
Authorities such as North Warwickshire confirm the national 10% requirement for small sites from April 2024 and require BNG information at submission. In Oldham, guidance highlights the exemptions for very small developments, reinforcing the need to show whether a scheme is exempt or compliant.
Local vs regional and national requirements for BNG Surveys
The national BNG framework introduced by the Environment Act 2021 requires all developments (except exemptions) to deliver a minimum 10% biodiversity net gain. This is enforced through the statutory biodiversity metric and approved BNG plans.
At a regional and local level, planning authorities add their own layers of guidance. Some councils simply apply the statutory 10% and publish validation notes confirming what evidence must be submitted (e.g. BNG survey results, baseline metric workbook, habitat maps). Others, however, adopt supplementary planning documents (SPDs) or local frameworks with higher aspirational targets for example, 15% or 20% net gain where feasible.
Local variations can also cover:
- Format of submission (e.g. PDF BNG report, Excel metric, GIS files).
- Supporting surveys required (e.g. River Condition Assessment for watercourses).
- Preferred securing mechanism (section 106 agreement vs conservation covenant).
For developers and landowners, this means that while the 10% national requirement is universal, the detail of what needs to be submitted with your BNG survey can differ significantly by council. ACP stays up to date with each authority’s requirements so your submission is both nationally compliant and locally tailored.
Methodology: How ACP conducts a BNG survey
ACP follows a structured, transparent approach to every BNG survey. Our process is built around Natural England’s Statutory Biodiversity Metric User Guide, combined with best practice in ecological surveying. Each step is carefully documented so local planning authorities can audit the results with confidence.
BNG baseline survey
The first step is a BNG baseline survey. Our ecologists visit the site to:
- Map habitats using the UKHab classification system, which is the recognised standard in England.
- Assess habitat condition against the statutory criteria, recording whether areas are in good, moderate, or poor condition.
- Measure the size of each habitat parcel in hectares (area habitats) or kilometres (linear features such as hedgerows and rivers).
This baseline survey establishes the existing ecological value of your site. Without this clear evidence, no biodiversity net gain assessment can be validated.
River Condition Assessment (RCA)
If a site includes a stream, river, or canal, we also carry out a River Condition Assessment (RCA). This is a specialist element of a BNG survey, designed to measure the biodiversity units of watercourses. Using the Modular River Survey (MoRPh) method, we evaluate:
- Channel structure and flow type
- Bed and bank materials
- Riparian vegetation and encroachment
- Connectivity with the wider landscape
The RCA ensures that river units are properly included in the statutory metric and that your scheme accounts for both terrestrial and aquatic habitats.
Ecological metrics and biodiversity net gain assessment
Once baseline data is collected, it is entered into the statutory ecological metrics tool. This calculator converts habitat distinctiveness, condition, area/length and connectivity into biodiversity units. We then model the post-development scenario, inputting proposed habitats and enhancements.
The results provide a transparent biodiversity net gain assessment showing:
- Baseline biodiversity units
- Projected post-development units
- Net % change (must be at least +10%)
If the scheme cannot achieve the gain on-site, we explain options such as habitat creation, off-site units or statutory credits.
Mapping and data outputs
Clear mapping is central to every BNG survey. ACP provides:
- Baseline habitat maps
- Proposed habitat layout maps
- Connectivity diagrams (showing wildlife corridors)
- Figures to demonstrate habitat change and net gain
Maps are produced in GIS and exported to PDF, making them easy for planners to review and file alongside the planning application.
Integration with other reports
Our BNG surveys are never stand-alone. They integrate with:
- BNG Reports – the formal submission document for validation
- Habitat Management and Monitoring Plans (HMMPs) – which secure the 30-year management and monitoring
- Ecology surveys (e.g. PEAs, protected species) – where findings overlap
This joined-up approach ensures your planning application is complete and consistent across all environmental documents.
Outputs
Every ACP BNG survey results in:
- A BNG survey report (PDF) with methodology, results, and recommendations
- A completed metric workbook (Excel)
- Baseline and proposed habitat maps
- A short covering note aligned with the LPA’s validation checklist
Together, these outputs form the evidence base for your BNG submission, reducing the risk of validation delays and planning queries.
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!
BNG survey cost
One of the most common questions we receive is “how much does a BNG survey cost?”. At ACP, our professional fees for a straightforward BNG survey start from £399 + VAT. This entry-level price covers small, single-phase sites where baseline habitats are simple and easy to assess.
The actual BNG survey cost varies depending on several factors:
- Site size and complexity – Larger or multi-parcel sites naturally take longer to survey, and complex habitats such as wetlands or ancient hedgerows require more detailed assessment.
- Habitat types involved – A grassland-dominated site is quicker to assess than a site with multiple habitats such as woodland, scrub, ponds, and streams, which require condition scoring across categories.
- Additional assessments – If a site contains rivers, an accompanying River Condition Assessment (RCA) will be needed. Where protected species are present, additional ecology survey BNG work may also be required.
- Project structure – Multi-phase housing or large mixed-use schemes may need more than one BNG baseline survey and metric file to satisfy local planning authority (LPA) requirements.
It’s also important to note that our fee covers ACP’s professional time for preparing the survey and report. The LPA monitoring fee the charge the council recovers through a section 106 monitoring fee is separate and must be agreed with the planning authority.
With ACP you get clarity from the outset: a transparent fixed-fee quote, clear scope of works, and survey delivery typically within 5–10 working days.
Deliverables & formats
When you commission ACP to carry out a BNG survey, you receive a complete pack of outputs designed to meet both national requirements and your local planning authority’s validation list. Our deliverables are transparent, audit-friendly, and written in plain English for planners, while retaining the technical detail ecologists need.
BNG Survey Report (PDF)
A planner-ready narrative report that explains the methodology, survey findings, and recommendations. It includes baseline evidence, habitat condition scores, ecological metrics outputs, and notes on how the project can achieve 10% biodiversity net gain. This is the document most LPAs expect to see attached to your planning submission.
Metric Workbook (Excel)
A fully completed statutory metric file, showing baseline biodiversity units, post-development projections, and net gain calculations. We log all assumptions clearly, ensuring the file can be audited by planning officers without confusion.
Mapping Pack
Baseline habitat maps, proposed habitat layouts, and connectivity diagrams that show how wildlife corridors and green infrastructure will be delivered. Maps are prepared in GIS and exported to PDF for submission.
HMMP Summary
A concise overview of the long-term management framework, drawn from the Habitat Management and Monitoring Plan (HMMP). This includes 30-year management tasks, monitoring cadence, and responsibilities.
BNG Submission Support
A covering note aligned with your council’s validation checklist. This provides context for the BNG survey, confirming that all required outputs are included, reducing the risk of validation queries.
Deliverables at a glance
Deliverable | Inclusions | Benefit |
BNG Survey Report | Metrics, mapping, compliance notes | Planner-ready submission |
Metric Workbook | Baseline & post-development units, log notes | Transparent, auditable evidence |
Mapping Pack | Baseline & proposed habitats, connectivity | Reduces LPA queries and clarifies design |
HMMP Summary | 30-year management overview | Links survey results to long-term delivery |
Submission Support | Covering note aligned with validation lists | Provides clarity and reduces extra queries |
Timelines & costs
ACP understands that time is critical in planning. That’s why we deliver most BNG surveys within 5–10 working days of receiving your site drawings and survey access. For smaller, straightforward schemes, we can often provide results even faster, helping you avoid unnecessary planning delays.
The actual timeline depends on the complexity of the site and the surveys required:
- Simple sites with grassland or amenity habitats can be turned around quickly.
- Complex or multi-parcel sites involving woodland, hedgerows, or wetlands may take longer to assess and map.
- Where a site includes a river, an additional River Condition Assessment (RCA) must be factored in.
- If protected species are identified, additional ecology survey BNG work may be needed before we finalise the baseline.
Our professional fees for a BNG survey start from £399 + VAT for small, single-phase projects. The total cost can vary depending on:
- Site size and the number of habitat parcels to be surveyed.
- The variety of habitats and their condition complexity.
- Whether add-ons such as RCA or specialist species surveys are required.
- Multi-phase schemes that may require more than one BNG baseline survey and metric workbook.
Importantly, ACP’s fee covers the preparation of your BNG survey report, metric workbook, and mapping pack. The LPA monitoring fee, a separate charge recovered by the council through a section 106 monitoring fee is not included in our price and must be agreed directly with the planning authority.
With ACP you get clarity from the outset: transparent fixed-fee proposals, fast turnaround, and outputs designed to satisfy both national policy and local validation lists.
Why choose ACP for your BNG survey
Choosing the right consultant for your BNG survey is about more than just ticking a compliance box. ACP goes beyond the basics, delivering surveys that satisfy planning officers, integrate with your wider project, and give you confidence your scheme will move smoothly through validation.
Evidence-led
Our surveys follow Natural England’s statutory metric guidance and UKHab standards. We log every assumption in the metric workbook, ensuring your biodiversity net gain assessment is transparent and defensible.
Planner-friendly
ACP reports are written in plain English for planning officers, backed by robust ecological data. This reduces validation queries and keeps your application moving. Each BNG survey report is structured to match LPA checklists, making it easier for officers to approve.
Joined-up approach
We don’t deliver surveys in isolation. Every BNG survey links seamlessly to your Biodiversity Net Gain Report, Habitat Management and Monitoring Plan (HMMP), and where rivers are present River Condition Assessments (RCA). This integrated package avoids duplication and ensures consistency across all your environmental documents.
Future-proofed
BNG requirements continue to evolve, with some councils already exploring higher-than-10% targets. ACP stays ahead of policy shifts so your submission isn’t just compliant today, but aligned with emerging local requirements.
Stakeholder engagement
We support early engagement with planners, consultees and local communities, ensuring your BNG survey results are understood by all stakeholders. This collaborative approach builds confidence and reduces risk of objections.
National coverage
From central London to rural counties, ACP delivers BNG surveys across England, tailoring each submission to the policies of the local planning authority.
Where we provide BNG surveys
ACP delivers BNG surveys across England. Our ecologists work with developers, planners, architects and landowners in every region, tailoring surveys to the requirements of local planning authorities (LPAs). Because each LPA publishes its own validation notes, supplementary planning documents (SPDs) or biodiversity action plans, it’s important your BNG survey matches both national policy and local expectations.
London
The London Plan (Policy G6) requires biodiversity net gain across all boroughs. ACP provides BNG surveys in every London borough, from Westminster, Camden and Islington in the centre to Bromley, Croydon and Hillingdon on the edge. Boroughs often require detailed habitat mapping and clear metric outputs as part of validation. Our London surveys also reference urban green infrastructure priorities and habitat connectivity in line with borough design codes.
South East
The South East is one of England’s busiest regions for planning. ACP regularly undertakes BNG surveys in Surrey, Kent, East Sussex, West Sussex, Essex, Hampshire, Berkshire and Oxfordshire. Local councils often focus on wildlife corridors and climate change adaptation, especially in rural and coastal contexts. Our surveys provide UKHab mapping, condition assessments and metric workbooks that meet these expectations.
East of England
In Cambridgeshire, Hertfordshire, Bedfordshire, Norfolk and Suffolk, many authorities emphasise ecosystem services such as flood mitigation and soil health. ACP’s BNG surveys demonstrate how developments achieve compliance while contributing to wider biodiversity conservation strategies.
West Midlands (Metropolitan County)
In the West Midlands, including Birmingham, Coventry, Dudley, Sandwell, Solihull, Walsall and Wolverhampton, LPAs highlight the role of BNG surveys in urban regeneration. ACP ensures that survey outputs align with validation checklists, clearly evidencing how projects achieve 10% biodiversity net gain.
East Midlands
In Northamptonshire, Leicestershire, Derbyshire and Lincolnshire, BNG is often applied on large greenfield housing or mixed-use projects. Our BNG baseline surveys establish clear biodiversity unit values, enabling developers to plan habitat creation or biodiversity offsets where required.
South West
Counties such as Gloucestershire, Wiltshire, Dorset, Somerset, Devon and Cornwall have some of England’s most ecologically sensitive landscapes. ACP’s BNG surveys support compliance while addressing local priorities for climate change adaptation, habitat connectivity and natural capital approaches.
North & North West
ACP also carries out BNG surveys in Cheshire, Greater Manchester, Merseyside, Lancashire, West Yorkshire, South Yorkshire, North Yorkshire, East Riding of Yorkshire, County Durham, Tyne and Wear and Cumbria. Councils in these regions often stress the importance of biodiversity conservation alongside regeneration. Our surveys include baseline data, ecological metrics, and mapping to support smooth validation.
Frequently Asked Questions About BNG Surveys: What Developers and Landowners Need to Know
Understanding how Biodiversity Net Gain (BNG) surveys fit into the planning process can be confusing, especially with new legislation now making them a legal requirement for most developments. This FAQ section addresses the most common questions we receive from planners, developers, and landowners about BNG surveys: what they involve, when they’re needed, how they link to Biodiversity Gain Plans and metrics, and how to ensure your site assessments meet Natural England and local authority expectations. Whether you’re at the pre-application stage or preparing for post-development monitoring, these answers will help you navigate the BNG process with confidence and clarity.
What is a BNG survey?
A BNG survey is an ecological assessment that establishes the baseline biodiversity value of a site before development. It involves mapping habitats, assessing their condition and distinctiveness, and calculating biodiversity units using the statutory metric. The survey provides the evidence needed to show how a project will achieve at least 10% biodiversity net gain, as required under the Environment Act 2021. Without a BNG survey report, local planning authorities cannot validate your planning application.
Do I need a BNG survey for my application?
Yes. Since February 2024 for major developments and April 2024 for small sites, most planning applications must include a BNG survey or risk refusal. Councils now expect to see a baseline habitat assessment, a completed metric workbook, and a covering statement. Even if your project seems minor, a BNG baseline survey will confirm whether your scheme is exempt or requires formal biodiversity net gain submission.
How does a BNG survey differ from other ecology surveys?
A BNG survey focuses on habitats, not individual species. While Preliminary Ecological Appraisals (PEAs) and protected species surveys check for bats, birds or reptiles, a BNG survey records habitat type, condition and connectivity to calculate biodiversity units. Together, these surveys form a complete ecological picture, but the ecology survey BNG element is unique because it feeds directly into the statutory metric and the biodiversity net gain assessment.
How much does a BNG survey cost?
ACP’s professional fees for a BNG survey start from £399 + VAT for a simple site. The total BNG survey cost depends on site size, habitat complexity, and whether additional work such as a River Condition Assessment (RCA) or protected species surveys is needed. By comparison, many competitors advertise surveys from £499–£600. Our fixed-fee proposals give clarity and ensure you receive a planner-ready report, metric workbook and maps.
What is included in a BNG survey report?
A typical BNG survey report (PDF) includes: baseline habitat maps, condition assessments, ecological metric outputs, connectivity diagrams, and recommendations to achieve 10% net gain. ACP also provides the metric workbook (Excel) with logged assumptions, a mapping pack, and an HMMP summary. These outputs ensure your BNG submission is transparent, auditable and compliant with both national and local planning requirements.
What is a BNG baseline survey?
A BNG baseline survey is the initial site assessment that records all habitats in line with the UKHab system. Each habitat is mapped, scored for condition, and measured by area or length. These results are entered into the biodiversity metric to calculate the baseline biodiversity units. The baseline survey is the foundation for the entire biodiversity net gain assessment: your development must show at least 10% uplift compared to this baseline score.
Do small sites need BNG surveys?
Yes unless exempt. From April 2024, small sites (less than 1 hectare or fewer than 10 dwellings) must also demonstrate 10% biodiversity net gain. A BNG survey provides the evidence to confirm compliance. The only exemptions are very small impacts (e.g. less than 25m² of habitat), self-build projects under 0.5 ha, or certain permitted developments. ACP can advise whether your project qualifies for exemption or needs a full BNG survey and report.
How long does a BNG survey take?
Most BNG surveys can be completed in the field in one day, depending on site size. The reporting, mapping and metric analysis usually take another 5–10 working days. Larger or more complex sites may require more time, especially if rivers, wetlands or multiple habitat parcels are involved. ACP provides a timeline upfront in our fixed-fee proposal so you know when to expect your BNG survey report PDF.
How long is a BNG survey valid?
A BNG survey is generally valid for 12–24 months, depending on how quickly site conditions change. If your application is delayed or the site is altered, the survey may need to be updated. ACP advises on validity and can re-run your biodiversity net gain assessment quickly to ensure your baseline data is still acceptable to the local planning authority.
Do BNG surveys use Ordnance Survey mapping?
Yes. BNG surveys use OS base maps to georeference habitat boundaries and prepare GIS outputs. While this is unrelated to “learn Ordnance Survey BNG reading” (map coordinates), it ensures survey maps are accurate and can be checked against planning drawings. ACP provides high-quality PDF maps as part of every BNG survey report so planners and consultees can easily interpret the results.
What happens if my site cannot achieve 10% biodiversity net gain?
If your BNG survey shows that on-site habitats cannot deliver the full uplift, ACP will advise on off-site options. These may include creating habitats on other land you own, purchasing biodiversity units from a habitat bank, or, as a last resort, buying statutory credits. We also highlight design changes or biodiversity offsets that can reduce reliance on external measures.
Can ACP update my BNG survey if site conditions change?
Yes. If your scheme is redesigned, or if site conditions have changed since the original baseline, ACP can update your BNG survey report. We re-run the ecological metrics, refresh habitat maps, and issue a revised workbook. This keeps your submission valid, prevents planning delays, and ensures your project remains compliant with both the statutory 10% requirement and any local policies.
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.
- Biodiversity Net Gain Report and Audit Templates- CIEEM.
- Implementing statutory biodiversity net gain. NAO.
- Mandatory Biodiversity Net Gain in England. A Guide by CIEEM.
Recent Google Reviews
Explore Related Biodiversity Net Gain Resources
BNG surveys form the foundation of every Biodiversity Net Gain (BNG) project, capturing the data that drives accurate habitat valuation and metric outputs. To understand how survey findings feed into the wider process, start with the Biodiversity Net Gain Overview and step-by-step BNG Assessment Guide explaining how baseline information informs site scoring and design.
See how results are converted into biodiversity units using the Statutory Biodiversity Metric 4.0 or Small Sites Metric (SSM). Once data are analysed, our Biodiversity Gain Plan (BGP) and Habitat Management and Monitoring Plan (HMMP) templates show how survey outcomes translate into measurable improvements.
Developers can explore further technical tools through our BNG Templates & Downloads, understand budget implications with the BNG Monitoring Fee Calculator, and ensure legal compliance via BNG Legislation & Guidance. To see practical examples of completed assessments, view our BNG Case Studies & Portfolio.
Next Steps
- Send us your site drawings and boundary – ACP will review the scale of your project and advise what level of BNG survey is required.
- Receive a fixed-fee proposal – starting from £399 + VAT, with clear timelines and deliverables.
- Book your BNG survey – our ecologists carry out the baseline survey, mapping, and metric calculations.
- Draft outputs delivered – including your BNG survey report (PDF), metric workbook, mapping pack, and HMMP summary.
- Submission support – we provide a covering note aligned with your LPA’s validation checklist, and liaise with planning officers if clarifications are needed.
With ACP, your BNG surveys are completed quickly, transparently, and in line with both national guidance and local authority requirements.
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.