East Sussex BNG / County planning guidance
Biodiversity net gain in East Sussex starts with the right planning authority, habitat evidence and design. Use this guide to compare council policies, check the published nature recovery strategy and plan your next step.
ACP helps developers, architects, planners and landowners with habitat surveys, biodiversity calculations and practical delivery plans. We cover Eastbourne, Hastings, Lewes, Rother and Wealden, including sites within the South Downs National Park.
Reviewed 7 November 2026 · East Sussex and Brighton & Hove LNRS published June 2026
10% statutory objective / application dates / exemptions
The national statutory minimum is normally a 10% increase in biodiversity value for development subject to mandatory BNG. However, the law includes exemptions and transitional arrangements.
New rules took effect on 6 August 2026. For applications from that date, sites of 0.2 hectares or less may qualify for an exemption. This applies where development does not affect onsite priority habitat.
A separate exemption covers certain wholly temporary development lasting no more than five years, subject to its legal conditions. Meanwhile, the dedicated self-build and custom-build exemption ended for new applications from 6 August 2026.
These are national rules, not a blanket waiver of ecological survey or protected-species requirements. Moreover, an earlier application date or a section 73 variation may change the position.
For non-exempt projects, an up-to-date habitat baseline and the correct statutory biodiversity metric are essential. The Biodiversity Gain Plan is then normally submitted for approval after planning permission and before development starts.
See the BNG exemptions and thresholds guide for the detailed decision route. Also consult the current government planning practice guidance for transitional cases.
Some East Sussex authorities are consulting on stronger future BNG policies. These draft figures are not automatically adopted local requirements. We separate the statutory minimum, adopted planning policy and emerging proposals below.
Five councils / National Park / county matters
The postal county does not identify the decision-maker. First check the local planning authority and whether the site lies inside the South Downs National Park. In addition, confirm the latest validation list for the relevant application type; local requirements are not identical across councils.
| Planning area | Who generally deals with ordinary development? | Important BNG distinction |
|---|---|---|
| Eastbourne (outside the National Park) | Eastbourne Borough Council | Adopted Policy D9; emerging QE4 proposes 10% |
| Hastings | Hastings Borough Council | Adopted EN3 and related biodiversity policies; emerging SC10 |
| Lewes district (outside the National Park) | Lewes District Council | Adopted CP10; 2025 draft NE3 considered 20% for major schemes |
| Rother | Rother District Council | Adopted EN5 and DEN4; 2026 draft ENV10 proposes 20% |
| Wealden (outside the National Park) | Wealden District Council | Adopted 2013 Core Strategy; emerging plan and council interim BNG advice discuss 20% on qualifying sites |
| South Downs National Park area | South Downs National Park Authority | Adopted SD9 and 2025 BNG advice note; emerging SDN1 proposes 20%, or 33% on strategic greenfield sites |
| Waste, minerals and certain county development | East Sussex County Council, in its county-planning role | Different application route; check the adopted joint waste and minerals policies |
Brighton & Hove is a separate unitary planning area, even though it shares the East Sussex and Brighton & Hove Local Nature Recovery Strategy. West Sussex is another county with its own LNRS. Neither should be presented as a district within East Sussex.
Practical note: For a site near the National Park boundary, confirm the planning authority before ordering a policy-specific assessment. Planning-service arrangements can vary, but the Park remains the relevant policy authority within its boundary.
Adopted policy / emerging proposals / current national framework
Policies can add local ecological context, evidence requirements and design expectations. An emerging plan can also signal change. However, it should never be described as adopted until the council confirms adoption.
Eastbourne's Core Strategy (adopted February 2013), Policy D9: Natural Environment, protects green networks, biodiversity and habitats. The emerging Regulation 19 Local Plan includes QE1: Nature Recovery and QE4: Biodiversity Net Gain, with a proposed 10% BNG requirement for non-exempt development. The consultation is scheduled from October to 1 December 2026.
For sites within the South Downs National Park, check the Park's policies instead.
The adopted Hastings Planning Strategy (February 2014) includes EN2 Green Infrastructure, EN3 Nature Conservation and Improvement of Biodiversity and other biodiversity protections. The adopted Development Management Plan followed in September 2015.
The 2026 Regulation 19 draft, open for representations until 12 November 2026, includes proposed SC10: Habitat Protection, Biodiversity and Net Gain. This identifies a 10% minimum rather than an adopted Hastings-wide 20% rule.
For areas outside the National Park, the adopted 2016 Core Strategy and 2020 Local Plan Part 2 form the established planning policy framework. CP10 addresses the natural environment and landscape.
In its 2025 draft policy work, Lewes considered 10% BNG generally and 20% for major development, with viability evidence relevant. However, Lewes Cabinet decided on 1 October 2026 to pause progression to Regulation 19 while it reviews the plan's strategy and evidence. Therefore, the 20% figure remains a draft proposal, not an adopted district-wide requirement. Before submission, check the latest council decision and the weight appropriate to the proposal.
Rother's adopted Core Strategy (September 2014) EN5 and Development and Site Allocations Plan (December 2019) DEN4 address biodiversity, ecological networks and green space. In particular, DEN4 calls for a green-infrastructure masterplan on certain larger schemes.
Its 2026 proposed submission Local Plan includes ENV10, which proposes 20% BNG for qualifying development. The Regulation 19 consultation runs to 24 November 2026. Until any new policy takes effect, do not mistake the proposal for a statutory county-wide minimum.
Wealden's adopted Core Strategy dates from 2013. The council's interim BNG guidance discusses a 10% baseline and a potential 20% target on qualifying sites in emerging policy.
The Regulation 19 draft Local Plan consultation closed on 2 November 2026. That draft has not yet become the adopted plan. The exact application of any locally higher target must be checked against the relevant operative policy and decision date.
Within the Park, the adopted South Downs Local Plan (2019), Policy SD9: Biodiversity and Geodiversity, and the March 2025 BNG Technical Advice Note provide local guidance.
The May 2026 Regulation 19 draft proposes Policy SDN1: Nature Recovery. Its proposed BNG figures are 20% generally and 33% for strategic greenfield sites. These are emerging figures, not adopted thresholds. The draft also emphasises landscape fit and the location of off-site gains within the Park.
The current NPPF limits higher mandatory BNG standards to justified, deliverable, specific site allocations. It also tells decision-makers to give no weight to other policies requiring gains beyond the statutory framework. Therefore, a draft 20% or 33% figure does not establish a blanket requirement.
Read NPPF policies N1(2) and N2(3) alongside the applicable development plan and application date.
Published June 2026 / Local Habitat Map
The East Sussex and Brighton & Hove Local Nature Recovery Strategy (LNRS) was published on 24 June 2026. East Sussex County Council led it as the responsible authority. The strategy covers East Sussex and the separate Brighton & Hove area, not West Sussex.
Its published material sets out eight principles, 24 priorities and 106 practical measures. A Local Habitat Map shows areas where habitat creation and recovery may bring particular benefits. The strategy helps direct nature recovery and informs planning decisions.
For BNG, the map is a useful early design tool. It can help identify locally appropriate habitat improvements, but a mapped opportunity does not prove that a site can supply a specific number of biodiversity units. An ecologist still needs site surveys, condition assessment, the statutory metric and consideration of any legal constraints.
The LNRS is a material consideration in planning. Its suggested actions are not themselves legally binding, nor do they override protected-site rules.
Practical action: Review the official East Sussex and Brighton & Hove LNRS and Local Habitat Map while designing habitats. Then compare the map with the actual site baseline, proposed layout and management capacity.
Downland / woodland / wetlands / protected species
East Sussex includes chalk grassland and downland, ancient woodland, ghyll woodlands, river corridors, wetland habitats, coastal habitats and urban green infrastructure. This variation makes habitat choice and condition assessment important.
Chalk grassland can support diverse plants and invertebrates. Here, retaining good habitat may offer greater ecological value than substituting a generic planting mix. In the National Park, landscape context and dark corridors also matter.
Projects close to sensitive sites may require Habitats Regulations Assessment and other mitigation work. BNG calculations do not replace these legal protections. For Ashdown Forest, the project team should assess likely pathways such as recreation and air quality where relevant to the proposal.
Sites near the Pevensey Levels, Romney Marsh, Combe Valley or other wetlands require attention to hydrology, soils, habitat condition and designated-site boundaries. A visually attractive pond or meadow is not necessarily suitable for every site.
Ancient woodland and veteran trees deserve early avoidance and appropriate buffers. Hedgerows and watercourses may need their own metric modules and separate technical survey work. Where a watercourse is affected, consider a river condition assessment where appropriate.
Species surveys and licensing are separate from the habitat-unit calculation. Bat roosts, breeding birds, great crested newts and other protected species can affect design or timing, whether or not mandatory BNG applies.
Start with habitat protection and a realistic site design. Avoid preventable impacts before considering replacement units.
Practical project brief / six checks in order
Use this original worksheet before commissioning your final metric or completing the planning form. It helps you gather the evidence needed for a site-specific assessment.
| Check | What to record | Why it changes your next step |
|---|---|---|
| 1. Planning area | Red-line plan, postcode, whether any part lies inside the South Downs National Park | Identifies the policy authority and validation route |
| 2. Application date and type | Submission date, description, major/non-major, any section 73 history | Determines transition rules and which 2026 exemptions can apply |
| 3. Area and priority habitats | Total red-line area in hectares, evidence of onsite priority habitat | A site no larger than 0.2 ha is not automatically exempt if priority habitat is affected |
| 4. Ecological constraints | Designated sites, ancient woodland, trees, hedges, watercourses, protected species | Identifies evidence and avoidance measures beyond statutory BNG |
| 5. Habitat baseline and design | UKHab plan, condition assessment, metric version, losses and opportunities | Establishes the evidence needed to test a deliverable gain |
| 6. Delivery and stewardship | Onsite habitat space, off-site options, draft management responsibilities | Shows how gains could be secured and maintained |
Your working conclusion: “We have confirmed the planning authority; checked the current exemption position; identified constraints; and know what baseline evidence to obtain.”
If any line remains uncertain, commission the relevant ecological advice before fixing the design or claiming an exemption.
Habitat baseline / application documents / delivery
A proportionate scope begins with a defensible habitat baseline. For a site subject to BNG, the project may need:
The detailed calculations are explained in our BNG assessment service and statutory metric guidance. For survey scope, see our BNG survey page.
The national minimum information requirements apply across East Sussex, including Eastbourne and Lewes. Under Article 7 of the Development Management Procedure Order, a relevant planning application needs:
These national items are separate from any additional information reasonably required by the local planning authority. For Eastbourne and Lewes, check the joint planning application guidance and council validation lists before submission. The exact local additions depend on the proposal; do not assume one council's checklist applies to the other.
National BNG application information requirements explain the minimum evidence and when a council may seek more detail.
At application stage, provide the mandatory BNG information and any justified local ecological evidence. Later, a relevant permission normally requires an approved Biodiversity Gain Plan before work starts. Do not describe the final gain plan as a universal national prerequisite for validating the original application.
For significant habitat enhancements, long-term delivery may need a Habitat Management and Monitoring Plan. Significant onsite gains and registered off-site gains generally require legal security for at least 30 years.
Council-reported cases / Bexhill / Peasmarsh
Rother District Council has published two useful BNG approval examples in its biodiversity duty report. These are council-reported planning cases, not claims about ACP projects.
Bexhill: mix of onsite and off-site gains. At 81 Cooden Drive, Bexhill, the council reported an approved gain plan linked to application RR/2024/2052/P and conditions case RR/2025/1677/DC. It described onsite grassland and trees alongside off-site provision.
Peasmarsh: off-site units for a replacement dwelling. For RR/2024/1040/P, Cornerways in Peasmarsh, the council recorded an approved gain plan RR/2025/511/DC and 0.49 off-site biodiversity units. The council explained that onsite net gain was not achievable for that scheme.
Together, these examples show how the habitat baseline and site layout can lead to different delivery approaches.
Delivery hierarchy / registered units / project costs
Yes, where the scheme meets the applicable rules and the gains are properly secured. First consider the development's ecological impacts and the relevant biodiversity gain hierarchy.
For major development, the hierarchy continues to give priority to onsite habitat improvement and creation before registered off-site units, with statutory credits last. For non-major planning applications made on or after 6 August 2026, onsite and registered off-site gain options may be considered at an equivalent level. Statutory credits remain the last option.
An off-site habitat bank must have the necessary legal agreement and registration. Units need to be allocated to the development. Geographic suitability and the current metric's spatial risk rules also matter.
Read more about off-site biodiversity units. For budgeting, use our BNG costs guide. No single county price can be quoted reliably without a project scope and the actual units needed.
Scope / survey / plan delivery
ACP can help bring habitat evidence, metric calculations and planning design together.
Step 1 — Define the brief. Send us the site location, red-line boundary, proposed use, drawings and planning timetable. We check the appropriate BNG and ecology route.
Step 2 — Establish the evidence. We identify the survey requirements, assess habitats and prepare relevant metric calculations. Where needed, the scope also addresses protected-species or watercourse work.
Step 3 — Plan delivery. We explain achievable onsite improvements, any off-site shortfall and management considerations. The resulting information supports your planning team and the relevant gain-plan stage.
Early advice can help avoid redesign, unsuitable habitat commitments and preventable programme delays.
Practical answers / project planning
Mandatory BNG applies to qualifying development under national law across England, including East Sussex. The standard statutory objective is 10%. However, application dates, exemptions and site characteristics matter. Check them before preparing a metric.
For applications made on or after 6 August 2026, development sites of 0.2 hectares or less can qualify if no onsite priority habitat is impacted. Transitional and section 73 rules may alter the position. Ecological protection still applies even where mandatory BNG does not.
No. The earlier dedicated self-build and custom-build exemption ended for new planning applications made from 6 August 2026. An eligible small site may qualify under another exemption, but only where its specific conditions are satisfied.
Rother's 2026 emerging Local Plan proposes 20% under draft Policy ENV10. That is not automatically an adopted requirement. Check the development plan and any policy changes at the date of the application.
Wealden's published interim advice and emerging plan discuss 20% on qualifying sites. The Regulation 19 consultation closed on 2 November 2026. Do not treat its emerging target as a universal operative requirement without checking the adopted policy position.
The South Downs National Park Authority applies its own adopted Local Plan and BNG Technical Advice Note. A May 2026 proposed plan includes draft targets of 20%, or 33% on strategic greenfield sites. These higher figures are not yet adopted merely because they appear in the draft.
Yes. The published strategy covers East Sussex and Brighton & Hove together. However, Brighton & Hove remains a separate planning authority. West Sussex has a different LNRS.
No. The map helps identify potential nature-recovery opportunities. A site-specific baseline, condition assessment and suitable statutory metric are still needed where mandatory BNG applies.
For a permission subject to the mandatory BNG condition, the gain plan must be approved before development begins. Minimum BNG information normally accompanies the planning application, but the final gain plan is a later statutory stage.
The answer depends on development type, application date, relevant hierarchy and delivery evidence. The 2026 changes allow eligible non-major applications to consider registered off-site gains alongside onsite options. Other mitigation and ecological protections still apply.
Species surveys address different legal and planning questions. The habitat metric alone does not establish whether protected species are present or whether a licence is required. Where risk is credible, separate survey evidence may be needed.
Send the postcode or site plan, red-line boundary, project description, proposed layout, existing ecological reports and target submission date. Tell us the planning authority if known. We can then propose a proportionate scope.
Talk to ACP / Site enquiries
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.
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East Sussex BNG
Reviewed 7 November 2026.
