Somerset BNG advice
Biodiversity Net Gain in Somerset
Plan your Somerset development around local habitat evidence, the right planning policies and nature recovery opportunities.
ACP Consultants can help with habitat surveys, biodiversity metric calculations and a practical BNG delivery plan for your Somerset site.
Local planning guidance
What does BNG mean for a Somerset development?
For most developments in scope, the statutory biodiversity gain objective is at least 10% above the habitat value before development.
An ecologist records the existing habitat types and their condition, usually using UKHab habitat classification. The statutory biodiversity metric then compares existing biodiversity value with the proposed habitat retention, enhancement or creation.
The metric is not a calculation of how much of a site stays green. It considers habitat area, distinctiveness, condition, strategic significance and the risks involved in creating new habitat. Hedgerows and watercourses have separate unit calculations.
Therefore, retaining existing woodland, hedgerows, ponds or other valuable habitats can reduce avoidable losses. This may improve the design and reduce pressure to source off-site units later.
For technical detail, see ACP's BNG assessment and habitat baseline surveys and statutory biodiversity metric calculations.
Local planning guidance
Which Somerset planning authority and Local Plan apply to your site?
Somerset Council is one unitary local planning authority for ordinary development outside Exmoor National Park. However, older adopted policies remain relevant in its different former district areas.
For example, a development in Bridgwater may fall under the Sedgemoor Local Plan. A site near Frome can be governed by the Mendip plan. Meanwhile, parts of Exmoor follow the National Park's own adopted plan.
For wider geographical searches, North Somerset and Bath and North East Somerset also need separate treatment. Their planning policies are not part of Somerset Council's adopted Local Plan framework.
| Where is the development? | Ordinary planning authority | Adopted policy area to check | LNRS area |
|---|---|---|---|
| Frome, Wells, Glastonbury, Street and Shepton Mallet | Somerset Council | Former Mendip Part I 2014, Part II 2021, 2025 Limited Update; DP5 ecology | Somerset LNRS |
| Bridgwater, Cheddar and Burnham-on-Sea | Somerset Council | Former Sedgemoor Local Plan 2019; D20 biodiversity | Somerset LNRS |
| Yeovil, Chard, Crewkerne and Wincanton | Somerset Council | Former South Somerset Local Plan adopted 2015; EQ4 biodiversity | Somerset LNRS |
| Taunton and Wellington | Somerset Council | Former Taunton Deane Core Strategy and adopted Site Allocations/Development Management Plan | Somerset LNRS |
| Minehead, Watchet and former West Somerset land outside Exmoor | Somerset Council | Former West Somerset Local Plan 2032, adopted 2016 | Somerset LNRS |
| Within Exmoor National Park | Exmoor National Park Authority | Exmoor Local Plan adopted 2017; CE-S3 and CE-D2 | Somerset LNRS for Somerset portion; Devon LNRS for Devon portion |
| Weston-super-Mare, Clevedon, Portishead, Nailsea | North Somerset Council (separate unitary) | Core Strategy CS4, DM8 and 2024 Biodiversity SPD; Local Plan 2041 submitted, not adopted | West of England and North Somerset LNRS |
| Bath, Keynsham, Radstock and Midsomer Norton | Bath and North East Somerset Council (separate unitary) | Adopted Local Plan Partial Update January 2023, NE3 and NE3a BNG | West of England and North Somerset LNRS |
| Minerals and waste development in Somerset outside Exmoor | Somerset Council in its minerals and waste role | Minerals Plan 2015; Waste Core Strategy 2013; new joint plan is only emerging | Somerset LNRS, subject to actual site location |
The former Mendip, Sedgemoor, Taunton Deane, South Somerset and West Somerset councils no longer exist as local planning authorities. Their policy areas remain useful for identifying the adopted development plan.
Somerset Council adopted Local Plans and policies map selection.
Prepare your site brief
Somerset BNG: six practical evidence checks
Use these questions to organise your plans, habitat information and planning requirements before commissioning an assessment.
| Question | Why it matters | Evidence to collect |
|---|---|---|
| 1. Which council and inherited Local Plan area apply? | There are Somerset Council, Exmoor, North Somerset and B&NES routes. Somerset Council still uses different former-district adopted policies. | Site location/red-line plan, council map and adopted policy lookup. |
| 2. When was the application made, and is BNG required? | August 2026 introduced a red-line site ≤0.2ha exemption with priority-habitat conditions and changed non-major gain hierarchy. Self/custom-build-specific exemption was removed for new applications. | Application and section73 history, site area, habitat impacts and government exemptions guidance. |
| 3. What existing habitats and protected features are affected? | Wet grazing marsh, limestone grassland, ancient woodland, hedgerows, watercourses and Mendip bats may require distinct surveys and legal tests. | UKHab baseline and condition data, local ecological records, tree/species/designation screening and current relevant SAC guidance. |
| 4. Which mapped nature recovery measure matches the site? | Somerset's LNRS is different from West of England/North Somerset. An opportunity polygon does not automatically award a metric strategic score. | Correct official LNRS, parcel map, mapped potential measure, habitat action, current metric version and strategic significance evidence. |
| 5. Does a separate phosphate or Ramsar assessment apply? | Somerset Levels and Moors/River Axe nutrient impacts depend on catchment and development. Phosphate P-credits and BNG units are different things. | Affected catchment guidance, phosphate budget, NNAMS/shadow HRA or appropriate assessment and separate mitigation where necessary. |
| 6. How will biodiversity gains be delivered and managed? | Check major/non-major hierarchy, habitat trading, offsite legal agreements, registration/allocation and minimum management term for significant gains. | Metric workbook, design/HMMP, appropriate legal agreement and government gain sites register. |
Bring your red-line plan, development proposals and any existing ecology reports. Discuss the evidence for your Somerset site with ACP.
Local planning guidance
Somerset's published Local Nature Recovery Strategy
Somerset Council published its Local Nature Recovery Strategy (LNRS) on 26 March 2026. The strategy was approved by Somerset Council on 11 March and supported by Exmoor National Park Authority for its relevant area.
The strategy provides an evidence base for habitat restoration and nature recovery. It contains eight habitat themes, 42 priority outcomes and 153 actions to support 150 priority species.
It is relevant to Somerset Council's area and the Somerset portion of Exmoor National Park. It does not replace the separate West of England strategy used by North Somerset and Bath and North East Somerset.
What does Somerset's Local Habitat Map show?
The Local Habitat Map helps identify where existing habitats are important and where further restoration or habitat creation could benefit nature.
- Areas of Particular Importance for Biodiversity (APIBs): established important wildlife areas, including protected sites, Local Wildlife Sites and mapped irreplaceable habitat.
- Areas that Could Become of Particular Importance (ACBIs): areas identified as having potential for habitat restoration, creation or connection.
- Potential measures: mapped actions linked to nature recovery priorities and specific habitat opportunities.
Mapped opportunities can inform design and the strategic-significance component of the statutory metric. However, a site inside an opportunity area does not automatically receive an uplift.
The proposed habitat type, action and location must match the relevant mapped measure and current metric guidance. An LNRS map also does not establish the site's actual habitat condition or make off-site units available for sale.
Somerset Local Nature Recovery Strategy and Local Habitat Map.
Different maps apply in North Somerset and Bath
The West of England and North Somerset Local Nature Recovery Strategy was launched in November 2024. It covers North Somerset, Bath and North East Somerset, Bristol and South Gloucestershire.
Therefore, a proposal in Weston-super-Mare or Bath must not simply use Somerset Council's LNRS map. Instead, use the correct West of England Local Nature Recovery Toolkit and the actual council's adopted planning policies.
Local planning guidance
Does your Somerset application need statutory BNG?
The statutory gain requirement depends on the development category, application date, site area and habitat impacts.
For qualifying new planning applications made on or after 6 August 2026, a development on a red-line site no larger than 0.2 hectares is exempt if it does not adversely affect onsite priority habitat.
Other exemptions can include genuine householder applications, developments with very limited habitat impacts and certain wholly temporary permissions lasting no more than five years. Each has its own conditions.
The former specific exemption for self-build and custom-build housing was removed for new planning applications made from 6 August 2026. Some earlier applications and section 73 permissions need different transitional checks.
An exempt BNG scheme can still need ecological surveys. For example, a small building project could affect a bat roost or an important hedgerow even if the 10% statutory BNG condition does not apply.
Do not assume the small-site exemption applies merely because the proposed building footprint is less than 0.2 hectares. The relevant area is the application site within its red-line boundary.
For detailed conditions, consult ACP's BNG exemptions guide and the latest government exemptions guidance.
Local planning guidance
Somerset Council's local BNG validation requirements
Somerset Council has additional local BNG validation requirements for relevant applications. These were formally adopted as an addition to its existing local checklists on 14 February 2024.
The council's BNG Guidance Note was updated on 15 January 2025. Version 2 includes guidance on defining significant onsite habitat gains and their management.
Its published information identifies relevant documents that may be needed, depending on the application and habitat impacts:
- Wildlife and ecology survey information.
- Biodiversity checklist and any applicable arboricultural report.
- Biodiversity Net Gain Statement using the council's template.
- Completed statutory biodiversity metric and suitable habitat drawings.
- The council's BNG declaration form.
- SHEP or HEP habitat evaluation information, where necessary.
These are locally published document categories, not a statement that every Somerset planning application requires every report. The actual list must be matched to development type, existing habitats and any exemption.
The council also provides specific guidance for coastal and floodplain grazing marsh, relevant to the Somerset Levels and other wet landscapes.
Apply the current national exemption rules alongside the relevant local validation list. The formal statutory Biodiversity Gain Plan is normally approved after permission and before commencement, not always lodged with the initial application.
Local planning guidance
Which adopted Local Plan policies are important in Somerset?
The current adopted plan depends on which former district area contains the site. New legislation applies across England, but adopted local ecology policies and designations remain relevant.
Mendip: DP5 and the 2025 adopted Limited Update
The Mendip Local Plan Part I was adopted in December 2014. It includes DP5, Biodiversity and Ecological Networks, and related policy DP6, Bat Protection.
Part II was adopted in December 2021. Following judicial review of several allocations, a Limited Update was adopted on 25 September 2025.
For planning in Frome, Wells, Glastonbury or the wider Mendip area, the latest adopted policies map must therefore be used. The superseded housing allocations should not be treated as current.
Mendip also includes sensitive habitats and potential bat foraging or commuting networks. The correct response depends on the site and species evidence.
Sedgemoor: D20 Biodiversity and Geodiversity
The former Sedgemoor area uses its Local Plan 2011–2032, adopted on 20 February 2019.
Relevant planning documents and recent council decisions refer to D20, Biodiversity and Geodiversity. That policy can matter for habitats, ecological networks and proposed enhancements.
Developments near Bridgwater or the Somerset Levels may also need separate floodplain, watercourse or nutrient analysis. These constraints should be assessed independently of a simple BNG percentage.
South Somerset: EQ4 and wider ecology policies
The South Somerset Local Plan 2006–2028, adopted on 5 March 2015, remains the adopted policy starting point for many developments around Yeovil, Chard, Crewkerne and Wincanton.
Its EQ4, Biodiversity, addresses ecological conservation and habitat connections. Other environmental policies and identified saved policies may also apply.
In particular, an existing woodland, hedge or bat habitat can shape planning design even where an applicant expects to create more habitat elsewhere.
Taunton Deane and West Somerset: two inherited policy frameworks
For Taunton and Wellington, adopted planning policy includes the Taunton Deane Core Strategy 2011–2028 and the Site Allocations and Development Management Plan.
The Taunton Town Centre Area Action Plan can also be relevant for specific sites. Do not assume every proposal is governed solely by a single countywide plan.
Outside Exmoor, the former West Somerset area uses its Local Plan to 2032, adopted November 2016, together with any saved policies and the current policies map.
These older adopted documents remain relevant until they are replaced through lawful plan-making. Their ecological policies sit alongside the national statutory BNG framework.
A new Somerset Local Plan is being prepared — but is not adopted
Somerset Council is preparing a Somerset Local Plan 2025–2045 for its area outside Exmoor National Park.
It began the formal new-system process in April 2026. Its scoping consultation ran from June to August 2026.
The council's current timetable targets further content consultation in 2027 and adoption in March 2029. These dates are projections, not completed milestones.
Therefore, the inherited adopted Local Plans still matter. The emerging plan does not establish a county-wide 20% BNG requirement.
Local planning guidance
Exmoor National Park: separate planning and BNG guidance
Exmoor National Park Authority is the planning authority for land inside its boundary, including Somerset-side Exmoor sites.
Its Local Plan 2011–2031 was adopted in July 2017. Relevant ecological policy includes CE-S3, Biodiversity and Green Infrastructure, and CE-D2, Green Infrastructure Provision.
The Park Authority has a BNG Technical Guidance Note dated June 2024. It also maintains separate local validation requirements, wildlife triggers and biodiversity information.
An exempt statutory BNG proposal may still need appropriate ecological enhancement under the Park's adopted policies. Meanwhile, protected species and irreplaceable habitats require their own assessments.
The Somerset portion of Exmoor is covered by Somerset's LNRS. The Devon portion is outside that strategy area. Therefore, a development should use the LNRS appropriate to its actual location.
Local planning guidance
North Somerset and Bath: separate councils and policy obligations
Some users search for Somerset BNG when their site is actually in North Somerset or Bath and North East Somerset. The difference matters for planning validation and nature recovery mapping.
North Somerset
North Somerset Council's operative planning documents include Core Strategy CS4, Nature Conservation, and Sites and Policies DM8, Nature Conservation.
It adopted a Biodiversity Supplementary Planning Document in January 2024. Its North Somerset and Mendip Bats SPD was updated in April 2026.
The proposed Local Plan 2041 was submitted for independent examination on 22 May 2026, but it is not yet adopted.
North Somerset uses the West of England LNRS. The council also has its own planning validation list, reviewed in December 2025.
Bath and North East Somerset
Bath and North East Somerset Council adopted its Local Plan Partial Update in January 2023, including Policy NE3a, Biodiversity Net Gain, and related nature conservation policy NE3.
Its new Local Plan remains in preparation. The adopted policies continue to apply, alongside current national exemptions and the statutory metric.
Bath and North East Somerset also uses the West of England and North Somerset LNRS.
Use the relevant council’s application checklist and adopted policies for your site.
North Somerset BNG guidance and Bath and North East Somerset BNG.
Local planning guidance
Somerset Levels and Moors: phosphate mitigation is separate from BNG
In parts of Somerset, development must consider phosphate impacts on the Somerset Levels and Moors Ramsar site or the River Axe Special Area of Conservation.
This is not the same as statutory biodiversity net gain. A project can need both a BNG assessment and a separate nutrient neutrality assessment, depending on its location and likely effects.
For affected development, a phosphate budget and suitable catchment-specific mitigation may be needed before planning approval or the discharge of certain conditions.
The council has a Somerset phosphate budget calculator and separate advice for affected catchments. It identifies the River Brue, Parrett and Tone for certain phosphorus-mitigation arrangements.
Why the difference matters
- BNG units measure habitat biodiversity value and any statutory net gain.
- Phosphate mitigation credits address a water-quality impact against a particular protected-site catchment.
- One unit or credit type does not automatically replace the other.
- A local BNG habitat bank is not automatically a phosphate-mitigation provider.
- Nutrient mitigation must match the affected catchment and current regulatory requirements.
Somerset Council reports that the C G Fry Supreme Court judgment of 22 October 2025 and subsequent 2026 Ramsar protection changes affect how certain applications, reserved matters and conditions may be considered.
Therefore, do not assume a historic planning consent removes nutrient obligations. Equally, do not assume every Somerset site requires phosphate credits.
The correct approach is to check the actual catchment, application category and latest case-specific advice.
Somerset phosphate and catchment guidance and Somerset phosphate budget calculator.
Local planning guidance
Somerset habitats and other ecological constraints
Somerset contains important wetlands, grasslands, woodland, coastal habitats and moorland. Their ecological value and feasible enhancement measures vary widely.
Somerset Levels and Moors. Seasonal wet grassland, drainage channels, water levels and bird habitats can affect landscape design and habitat management.
Mendip grasslands and caves. Limestone grassland, cave systems and bats can trigger separate designated-site and species considerations. The Mendip Limestone Grasslands SAC and North Somerset and Mendip Bats SAC are relevant examples.
Exmoor. Moorland, woodland, river valleys and sensitive landscapes may be subject to National Park planning policy as well as ecology law.
Coastal habitats. Saltmarsh, coastal grazing marsh, mudflat and estuary features require careful habitat identification and may be affected by flood or coastal processes.
Rivers and hedgerows. Existing watercourses, mature trees and connected hedges can be important to retain. The statutory metric treats certain linear habitats separately.
These are county-level examples. An ecological consultant should confirm the actual habitats, protected sites, species and impact pathways for the specific development.
Local planning guidance
Somerset BNG planning evidence: six steps
1. Confirm the authority, application type and red-line site
Identify whether the proposal falls under Somerset Council, Exmoor, North Somerset or Bath and North East Somerset. For Somerset Council, select the correct inherited Local Plan area.
2. Check BNG exemptions and other ecological duties
Record the application date and permission history. Apply the current national BNG exemption criteria. Check any separate protected habitats, species or nutrient issues.
3. Establish the habitat baseline
Arrange suitable UKHab mapping, condition assessment and any necessary ecological investigations. Where watercourses and hedgerows are affected, include the relevant separate metric information.
4. Use the right Local Habitat Map and metric
Check Somerset's published LNRS or the separate West of England map, depending on location. Use the appropriate statutory metric. The latest published tool is version 1.1.0, updated November 2026; older published statutory versions may also be accepted.
5. Test design changes and habitat delivery
Avoid unnecessary losses, retain valuable habitats and assess realistic onsite measures. Where a compliant registered off-site route is needed, check habitat trading, distance/catchments and legal security.
6. Prepare the Gain Plan and long-term management
For an in-scope permission, the formal Biodiversity Gain Plan normally requires approval after planning permission and before commencement.
Significant onsite and registered off-site habitat gains are generally secured for at least 30 years, with appropriate management and monitoring.
See ACP's Biodiversity Gain Plan guidance and Habitat Management and Monitoring Plans.
Local planning guidance
How should a Somerset developer deliver onsite or off-site biodiversity gain?
For major development, the gain hierarchy gives preference to avoiding habitat impacts and suitable onsite gain measures. Registered off-site delivery may be needed where an onsite route cannot achieve the required outcome. Statutory credits remain the final option.
For qualifying non-major applications made on or after 6 August 2026, onsite enhancement, onsite creation and registered off-site gain can sit at the same priority level. Credits still remain last.
Any off-site units must be legally secured, registered, suitable under habitat trading rules and formally allocated to the development.
The LNRS map may show excellent habitat opportunities. However, mapped land is not automatically a registered gain site or evidence of units available for purchase.
Similarly, a phosphate-mitigation scheme should not be mistaken for a biodiversity gain-unit provider. The two markets address different statutory outcomes.
For the technical and commercial route, see ACP's off-site biodiversity units guide and the government gain sites register.
Local planning guidance
Somerset BNG planning checklist
Unsure what BNG evidence your Somerset planning application needs?
Send ACP the site location, proposed works, drawings and any existing ecology surveys. We can help identify the appropriate assessment route.
Local planning guidance
How ACP Consultants can help your Somerset project
A good BNG assessment should inform the development before its layout and planning evidence are finalised.
ACP can help identify the appropriate habitat baseline, review biodiversity metric inputs and consider feasible onsite or off-site gain options.
Where a site is affected by protected habitats, bats or nutrient neutrality, those questions should be investigated alongside BNG rather than treated as interchangeable calculations.
The scope should reflect the actual land, planning authority and development type. Not every Somerset project needs the same surveys or reports.
For a broader overview, see ACP's BNG process guide and BNG consultant services.
Local planning guidance
Frequently asked questions about BNG in Somerset
Is biodiversity net gain compulsory for all Somerset planning applications?
No. It normally applies to qualifying development, but statutory exemptions and saved arrangements exist. The authority, application type, date, red-line area and habitat impacts must be checked.
Does Somerset have one adopted Local Plan?
No. Somerset Council still applies adopted plans for former Mendip, Sedgemoor, South Somerset, Taunton Deane and West Somerset areas. A replacement Somerset Local Plan is being prepared but is not yet adopted.
Does the Somerset LNRS cover North Somerset and Bath?
No. North Somerset and Bath and North East Somerset fall within the separate West of England and North Somerset LNRS. Somerset Council published its own strategy on 26 March 2026.
When was Somerset's Local Nature Recovery Strategy published?
It was published on 26 March 2026. Somerset Council is the responsible authority, and Exmoor National Park Authority supported the strategy for its relevant Somerset area.
Does being inside an LNRS opportunity area automatically increase biodiversity units?
No. A proposed habitat measure must match the mapped location, habitat action and current statutory metric requirements. An opportunity area is not a field survey or a registered habitat bank.
Can a Somerset site of 0.2 hectares or less be exempt?
A qualifying new application made on or after 6 August 2026 may be exempt if its red-line site is no larger than 0.2 hectares and the proposal does not adversely affect onsite priority habitat. Transitional rules may apply.
Are self-build homes automatically exempt from BNG?
No. The specific self-build/custom-build exemption was removed for new planning applications made from 6 August 2026. Another exemption may apply if its separate conditions are satisfied.
Does planning within Exmoor National Park use Somerset Council's Local Plan?
No. Exmoor National Park Authority has its own Local Plan 2011–2031 and BNG Technical Guidance Note. Within the Somerset part of Exmoor, the Somerset LNRS provides the relevant nature recovery context.
Can Somerset Council ask for additional BNG evidence?
Yes. It adopted local BNG validation requirements in February 2024 and maintains its own BNG Guidance Note. The exact required documents depend on the application, site and ecology.
Are phosphate credits the same as biodiversity net gain units?
No. Phosphate mitigation credits address nutrient effects on protected water catchments, while BNG units represent biodiversity habitat value. Some developments may need both, and each requires its own evidence.
Can I purchase off-site BNG units for a Somerset development?
Potentially, if appropriate units can be legally secured, registered and allocated. Habitat type, trading, spatial factors and the gain hierarchy all matter. The existence of a habitat bank does not guarantee availability or price.
What should I provide for a Somerset BNG quotation?
Send the site location or red-line plan, development description, latest drawings, planning stage and any ecology reports. Identifying the authority and known phosphate issues also helps define a suitable scope.
Local planning guidance
Discuss biodiversity net gain for your Somerset site
If you are preparing a planning application, assessing existing habitat or considering how to meet BNG requirements, the first step is understanding your site.
Tell ACP about your Somerset development. We can help clarify which ecological evidence is relevant and outline a suitable route forward.
Talk to ACP / Site enquiries
What does your site need next?
Tell us where the site is, what you plan to build and how far the application has progressed. We’ll use that context to discuss the surveys, calculations or plans your project needs.
What to have to handA red-line plan, an existing ecology report or a request from the council can help us scope the work. Start with whatever you already have.
Request a site-specific quotation
Start with the information you have. We ask for your email, site location and enquiry, with a telephone number at the final step.
We use your details to respond to your enquiry. Read our Privacy Policy.
Somerset BNG
Sources and references
Reviewed 7 November 2026.
Official planning and nature recovery sources
- GOV.UK biodiversity net gain planning guidance — national rules, hierarchy and BGP timing.
- Government BNG exemptions — reforms in force 6 August 2026.
- Statutory biodiversity metric — most recent November 2026 edition.
- Somerset Council BNG Guidance Note and validation — Somerset-specific application evidence.
- Somerset Local Nature Recovery Strategy and map — published March 2026.
- Somerset adopted Local Plans — choose the applicable inherited policy area.
- Somerset Local Plan 2045 timetable — emerging, not adopted.
- Exmoor National Park BNG guidance — separate national park LPA and policies.
- West of England and North Somerset LNRS Toolkit — correct separate map for North Somerset and Bath.
- North Somerset biodiversity guidance — separate local requirements.
- Bath and North East Somerset BNG — NE3a adopted policy and current exemptions.
- Somerset phosphate catchment guidance — separate Ramsar and River Axe mitigation duties.
- Somerset phosphate budget calculator — not the biodiversity metric.
- Government biodiversity gain site register — registered offsite gains and allocations.