Dorset BNG advice
Biodiversity Net Gain in Dorset
Plan your Dorset development around local habitat evidence, council requirements and nature recovery opportunities.
ACP Consultants can help with habitat surveys, biodiversity metric calculations and a practical BNG delivery plan for your Dorset site.
Local planning guidance
Which Dorset planning authority deals with your application?
For ordinary planning applications, first check whether the site falls within Dorset Council or BCP Council.
Dorset Council covers places such as Dorchester, Weymouth, Bridport, Blandford, Shaftesbury, Swanage and Wimborne. BCP Council covers Bournemouth, Christchurch and Poole. There is no separate Dorset County Council that decides all ordinary planning proposals.
The two councils use different adopted planning documents and ecology validation processes. The local planning portal and historical plan area should be confirmed from the actual red-line boundary, not simply the postal town.
Use the Dorset BNG route finder below to identify the correct council, existing plan, statutory BNG position and other ecology checks.
Why are Bournemouth, Christchurch and Poole treated differently?
They are three historical planning areas within one BCP Council, not three independent current planning authorities.
Bournemouth has an adopted 2012 Core Strategy, Christchurch uses the 2014 Christchurch and East Dorset Core Strategy, and Poole uses its 2018 Local Plan, alongside relevant saved and neighbourhood policies.
A further complication is that the 2014 Christchurch and East Dorset strategy crosses today's council boundary. Christchurch is handled by BCP, while the former East Dorset area is handled by Dorset Council.
For minerals and waste projects, both councils also use a joint adopted minerals and waste framework, which requires a separate application-route check.
Prepare your site brief
Dorset BNG: find the right council and ecology checks
Use these five questions and the linked official sources to organise your plans, habitat evidence and planning requirements.
Is the site in Dorset Council or BCP Council?
Choose one of the two present unitary planning authorities. Bournemouth, Christchurch and Poole are three BCP policy areas, not three separate present councils.
Dorset Council — find the adopted historic plan area:
- West Dorset, Weymouth and Portland (2015)
- North Dorset (2016)
- East Dorset part of the 2014 Core Strategy
- Purbeck (2024)
BCP Council — find the inherited policy area:
- Bournemouth Core Strategy (2012) and saved policies
- Christchurch (2014 Core Strategy plus saved policies)
- Poole Local Plan (2018)
Where minerals or waste development is involved, check the joint mineral/waste framework and the actual deciding authority.
Does mandatory BNG apply to the proposal?
Check the application date, planning route, full red-line site area and priority habitat impacts. For qualifying applications made from 6 August 2026, the statutory BNG condition may not apply when the site is no larger than 0.2 hectares and the development does not impact on-site priority habitat.
Other householder, de minimis, temporary and transitional exemptions have distinct conditions. New self-build/custom-build applications do not automatically have the former general exemption.
Is separate local ecological review or BCP validation needed?
Dorset Council: its Biodiversity Appraisal Protocol (DBAP) can be relevant from 0.1 hectares or where species, important habitats or likely impacts trigger it. All applications complete its Biodiversity Checklist. DBAP evidence and certification are separate from statutory BNG.
BCP Council: use its planning validation checklist, BNG checklist and biodiversity checklist. Do not assume Dorset Council's DBAP thresholds or fees are automatically the BCP rules.
For example, a qualifying 0.15-hectare Dorset Council site might be statutorily BNG-exempt but still require local ecological review. Neither route guarantees the site is free of protected-species duties.
Are there protected heathland or nutrient catchment duties?
For a relevant site near the Dorset Heathlands, inspect the actual designated area and current visitor-mitigation framework. A habitat metric is not a replacement for the Habitats Regulations, SANG or SAMM duties.
Where development is within a relevant nutrient catchment, check the council's latest nitrogen or other nutrient rules. Dorset Council's catchment guidance lists Poole Harbour, River Avon, Chesil and the Fleet, River Axe, and Somerset Levels and Moors.
BCP's Poole policy and nutrient information describes current local submission requirements. Nutrient credits are not registered BNG biodiversity units.
Which habitat evidence, LNRS map and delivery documents are relevant?
Review the actual habitat/UKHab baseline, condition evidence, watercourses and hedgerows, planning layout and metric tool/edition. Check the published Dorset Local Nature Recovery Strategy, its written priorities and three statutory map layers. Open DorsetExplorer Nature Recovery for the mapped measures and full data.
A marked high-opportunity area is not an automatic increase in the statutory metric. Significant gains may need a Biodiversity Gain Plan, 30-year Habitat Management and Monitoring Plan, and correctly registered/allocated off-site units where applicable.
Document the site location, mapped measure, ecological suitability, evidence date and any legal or protected-site constraint.
Bring your red-line plan, proposed development and existing ecology reports. Discuss the evidence for your Dorset site with ACP.
Local planning guidance
Dorset adopted Local Plans and BNG policy differences
Both councils must apply relevant national BNG law. Nevertheless, the adopted development plans, local validation lists and ecology assessment processes are not identical.
Dorset Council: four inherited adopted plan areas
| Site area | Adopted planning framework | Biodiversity and submission considerations |
|---|---|---|
| West Dorset, Weymouth and Portland | Joint Local Plan 2011–2031, adopted October 2015. | ENV2 Wildlife and Habitats and other relevant environmental policies. Check Dorset Council's local list, BNG guidance and Biodiversity Appraisal Protocol. |
| North Dorset | North Dorset Local Plan Part 1 adopted January 2016, alongside any still-operative saved policies. | Policy 4 Natural Environment. Confirm site boundaries, ecological networks, habitat features and Dorset Council evidence requirements. |
| East Dorset | Christchurch and East Dorset Core Strategy adopted April 2014, with relevant saved East Dorset policies. | ME1 biodiversity and ME2 Dorset Heathlands where applicable. East Dorset land is now within Dorset Council, not BCP. |
| Purbeck | Purbeck Local Plan 2018–2034, adopted July 2024; relevant Swanage and neighbourhood plans. | E10 Biodiversity and Geodiversity, plus E7 protected sites, E8 Dorset Heathlands and E9 Poole Harbour where relevant. This is the newer adopted Purbeck plan. |
BCP Council: Bournemouth, Christchurch and Poole adopted plan areas
| Site area | Adopted planning framework | Biodiversity and submission considerations |
|---|---|---|
| Bournemouth | Bournemouth Core Strategy 2012, plus still-operative saved policies and relevant plans. | CS33 Dorset Heathlands where applicable. Use BCP's current biodiversity and BNG validation checklists. |
| Christchurch | Christchurch and East Dorset Core Strategy 2014, plus retained Christchurch 2001 policies. | ME1 biodiversity and ME2 heathland protection. BCP Council processes the planning application. |
| Poole | Poole Local Plan 2018, alongside applicable neighbourhood plans. | PP32 nature and protected-site policy. Check Poole Harbour, Dorset Heathlands, nutrient and BNG obligations as applicable. |
Use the relevant adopted plan, mapped designations, local validation list and any neighbourhood plan for your site.
Have the councils adopted one new Dorset-wide Local Plan?
No. Dorset Council's single replacement Local Plan remains in preparation.
It restarted work under the new plan-making system in 2026. The scoping consultation ran from 21 September to 26 October 2026, and its next formal readiness stage was planned for November.
BCP's position is different. Its draft Local Plan submitted in June 2024 was withdrawn in June 2025. BCP published its Gateway 1 self-assessment on 30 October 2026. Its timetable schedules the content and evidence consultation for 9 November to 21 December 2026.
Neither process had produced a new adopted plan on 7 November 2026. A withdrawn draft, planned consultation or timetable cannot replace an adopted policy simply because it is more recent.
Local planning guidance
Statutory BNG and Dorset's Biodiversity Appraisal Protocol are different
One of the most important questions in Dorset is whether a project needs statutory BNG, local ecological review, or both.
For most non-exempt planning permissions, statutory BNG measures a development's habitat gains against the required minimum.
However, Dorset Council has a separate Dorset Biodiversity Appraisal Protocol (DBAP). This helps check impacts on protected species and important habitats, even where statutory BNG is not the main issue.
When might Dorset Council's DBAP apply?
Dorset Council says the DBAP applies to development sites of 0.1 hectares or more, or where there are known protected species or important habitat features, or likely biodiversity impacts.
All planning applications must complete the council's Biodiversity Checklist. Where DBAP is triggered, the Natural Environment Team may need to review the ecological information and issue a certificate confirming the agreed ecology evidence and mitigation.
The protocol is a separate review process, and the council publishes different review fees depending on application type.
What about the newer national 0.2-hectare exemption?
For qualifying planning applications made on or after 6 August 2026, development on a red-line site of 0.2 hectares or less may be exempt from the statutory BNG condition if the works do not affect on-site priority habitat.
Consequently, a Dorset Council scheme between 0.1 and 0.2 hectares may be exempt from mandatory BNG but still need DBAP-related ecological evidence.
Neither threshold is a universal declaration that a site contains no protected species. Local ecology duties and other protections must still be considered.
Does the same DBAP process apply throughout BCP?
Do not assume so. BCP Council publishes its own local validation list, a biodiversity checklist, a BNG checklist and supporting guidance.
Its evidence requirements depend on the proposal and location. For example, protected heathlands, coastal sites or Poole Harbour catchments can introduce additional questions.
The former general self-build exemption was removed for new applications from 6 August 2026. Use current national rules to determine statutory BNG applicability.
For a project in either council area, start with the actual planning form, latest local checklist and ecological site evidence.
Local planning guidance
How does a Dorset biodiversity net gain assessment work?
The process begins by assessing the biodiversity value of habitats before development. A suitable survey and mapping exercise identifies existing habitats, hedgerows, watercourses and their condition.
Next, the design team considers what should be retained or improved. New habitats can then be assessed using the statutory metric to estimate post-development biodiversity units.
Where mandatory BNG applies, the minimum objective is usually 10%. A Biodiversity Gain Plan then sets out how the requirement will be delivered and, where the statutory gain condition applies, must be approved before development begins.
The initial planning application may still need baseline habitat plans and metric information. Therefore, early design coordination usually prevents problems later.
Which statutory biodiversity metric is current?
The official Statutory Biodiversity Metric was updated to version 1.1.0 on 3 November 2026. The revised user guide also clarifies the treatment of watercourse spatial risk where developments span multiple waterbody catchments.
Earlier valid statutory metric editions remain usable where government guidance permits. However, a pre-statutory Metric 4.0 workbook is not appropriate for a new mandatory BNG calculation.
An eligible scheme may instead use the Small Sites Metric. Eligibility for the simplified tool is not the same as exemption from the statutory BNG condition.
The metric treats area habitats, hedgerows and watercourses separately. One category's surplus cannot simply erase a deficit in another.
Read our Statutory Biodiversity Metric guidance and Small Sites Metric guide for the detailed approach.
Local planning guidance
Dorset's Local Nature Recovery Strategy and habitat map
Dorset's Local Nature Recovery Strategy (LNRS) was published in December 2025 and launched more widely in March 2026.
Dorset Council led the work, supported by BCP Council, Natural England and local organisations. It provides one strategy covering both Dorset and BCP administrative areas.
The strategy sets out 13 priorities for nature recovery. These range from grassland, woodland, heathland and wetlands to coastal habitats, hedgerows, urban nature and species recovery.
It can help show where habitat creation or restoration might contribute to wider landscape improvements. However, the strategy does not automatically require a landowner to carry out a measure or approve a particular development.
What does Dorset's Local Habitat Map show?
Dorset's published Local Habitat Map contains three statutory layers:
- Nature areas of national importance identify recognised areas with important biodiversity protections.
- High opportunity nature areas identify broad locations where nature recovery could deliver substantial benefits.
- Potential activities suggest activities that may contribute to the strategy's written priorities.
The council also provides other useful layers for habitat connections, rivers and local nature areas. However, these additional layers are not the same as the three statutory LNRS layers.
The downloadable spatial data was updated in August 2026. Some layers are available only through the full DorsetExplorer viewer.
How to use the map for BNG
- Find the actual red-line site using the published DorsetExplorer Nature Recovery map.
- Check the correct layers, including potentially relevant habitat and nature recovery measures.
- Read the corresponding written priority to understand which activities could suit the site.
- Compare the mapping with a field survey, soils, water, existing habitats and other constraints.
- Document any strategic significance claim using current statutory metric guidance and a genuine habitat-measure match.
An opportunity area does not by itself guarantee extra biodiversity units, a suitable habitat creation site or an approved off-site unit allocation.
Local planning guidance
Dorset habitats and protected environmental constraints
Dorset has extensive ecological variety. Therefore, the right BNG design depends on the actual site, not a standard county-wide planting specification.
Lowland heathland and woodland
The Dorset Heathlands include important protected habitats. Parts of the county have sensitive heaths, woodland, ancient trees and species that can be affected by disturbance or development.
Early survey work should establish what can be retained and whether a separate Habitats Regulations Assessment is needed. New habitat units cannot simply replace duties to protect internationally designated sites.
Poole Harbour and the coastal environment
Poole Harbour is an internationally protected estuarine area. Coastal development and water quality can require additional assessment and separate mitigation.
The Dorset coast also includes Chesil and the Fleet, the Jurassic Coast and sensitive cliff and coastal habitats. Any proposal for saltmarsh, shoreline habitat or coastal nature recovery must consider tides, flooding and the relevant permissions.
Chalk grasslands, hedgerows and farmland
Chalk downs, species-rich grassland and rural hedgerow networks can offer important habitat connections. However, new grassland must be feasible for the soil and management conditions.
Established hedgerows and veteran trees should be evaluated before design decisions are fixed. The statutory metric cannot be used as a blanket justification for the loss of high-value ecological features.
Rivers, wetlands and urban ecology
The Frome, Piddle, Stour and Avon systems include river and floodplain habitats. A project may need watercourse-specific metric evidence, river condition assessment and separate water-related consents.
In Bournemouth, Poole, Weymouth and other settlements, green corridors, drainage features and some previously developed habitats may also be important. Urban habitat gains must be realistic and maintainable.
Local planning guidance
Dorset Heathlands and Poole Harbour: separate planning requirements
Some Dorset projects need more than the statutory BNG calculation.
For example, development near protected heathland may need measures addressing additional visitor pressure. In other places, development can affect water quality in a protected estuary or river.
These requirements arise through different planning and environmental tests. Therefore, they should not automatically be counted as additional BNG units.
What is the Dorset Heathlands planning framework?
The Dorset Heathlands planning framework addresses impacts from residential development close to designated heaths.
The jointly published 2020–2025 framework describes restrictions or mitigation in locations including the 400-metre and 400-metre to five-kilometre zones, depending on the designated site and scheme.
Appropriate mitigation may involve Suitable Alternative Natural Greenspace (SANG), access management and other agreed measures.
Because policies and guidance can change, check the latest operative council and Natural England advice for the site. Do not rely on a distance estimate without the actual designation boundary and current planning rules.
Is Poole Harbour nitrogen mitigation the same as BNG?
No. Qualifying development in the Poole Harbour catchment may need to demonstrate that additional nitrogen pollution is properly mitigated.
Dorset Council and BCP Council have updated their approaches. In particular, the older nitrogen reduction SPD methodology has been withdrawn or replaced, and BCP's transitional arrangements changed in August 2026.
The actual nutrient assessment depends on the catchment, wastewater discharge, application type and current guidance. There may also be separate rules relating to other protected Dorset catchments.
Nutrient mitigation credits are not the same as registered biodiversity units. A project should avoid double-counting measures that are already legally required to protect a designated site.
Local planning guidance
On-site and off-site biodiversity gain in Dorset
A good BNG strategy starts with the habitats that can realistically be retained. Next, consider appropriate on-site creation and enhancement, taking account of design, maintenance, landownership and ecology.
Where a shortfall remains, registered off-site biodiversity units may be appropriate if the relevant legal and metric rules are met.
For qualifying non-major applications made from 6 August 2026, on-site enhancement or creation and registered off-site gains sit at the same level of preference within the revised biodiversity gain hierarchy. Statutory biodiversity credits remain last resort.
However, major applications and earlier permissions can follow different hierarchy rules. Separate protected-site or nutrient mitigation requirements must still be addressed.
Can a Dorset landowner provide BNG units?
Potentially. However, owning a suitable area of land does not automatically create saleable biodiversity units.
An off-site gain site needs an appropriate ecological baseline, habitat proposals, long-term management, a legally secured agreement and registration. The units must then be properly allocated to a development.
The Dorset LNRS can help investigate whether proposed habitats contribute to a wider nature recovery priority. Yet an LNRS mapped opportunity is not a registered gain site.
Any commercial availability, habitat type or price must be confirmed for the real site. Do not assume an advertised habitat bank has units suitable for every development.
What does 30-year management involve?
Significant on-site and registered off-site gains normally need legal protection and management for at least 30 years.
A Habitat Management and Monitoring Plan (HMMP) can set out habitat creation, maintenance, monitoring, responsibilities and corrective action if the habitat does not develop as expected.
A credible plan considers water, soils, access, cost and long-term land management. A calculated 10% gain on its own does not establish feasibility.
See our off-site biodiversity units guidance and Habitat Management and Monitoring Plan advice.
Local planning guidance
Dorset BNG planning submission checklist
Use this checklist to prepare your ecological brief and organise the evidence for your planning application.
A complete submission should explain what the proposed habitats are, why they are suitable and how they will be delivered.
Local planning guidance
How ACP can help with Dorset biodiversity net gain projects
1. Establish the planning and ecology route
We review the site's location, proposed works, application stage and available information. We can then help identify the appropriate surveys and BNG reporting scope.
2. Assess the habitats and test design options
Where instructed, the scope may include a habitat baseline, condition survey, metric calculation and biodiversity reporting. We can work with the design team to understand realistic retention and improvement options.
3. Prepare the evidence for delivery
The agreed work may include a BNG report, Biodiversity Gain Plan information and habitat management advice. Separate ecological mitigation, nutrient assessment or legal agreements must be addressed where required.
Need clarity on a Dorset BNG planning requirement?
Request a Dorset BNG scope review
For a coordinated application, see our Biodiversity Net Gain report service and Biodiversity Gain Plan guidance.
Local planning guidance
Dorset biodiversity net gain FAQs
Which council handles BNG planning applications in Dorset?
For ordinary planning applications, use Dorset Council or Bournemouth, Christchurch and Poole Council, depending on the red-line boundary. These are two separate unitary planning authorities. The relevant adopted Local Plan may depend on a smaller historical plan area within the correct council.
Has Dorset Council adopted one Local Plan for the whole area?
No. Dorset Council continues to use adopted plans covering the former West Dorset/Weymouth & Portland, North Dorset, East Dorset and Purbeck areas. Its single replacement Local Plan was in preparation in November 2026. The Purbeck Local Plan adopted July 2024 is an important recent adopted plan.
Is the 2024 Bournemouth, Christchurch and Poole Local Plan adopted?
No. BCP's submitted 2024 draft Local Plan was withdrawn in June 2025. A new plan-making process started 30 October 2026. Until a replacement is adopted, the Bournemouth, Christchurch and Poole inherited adopted plans and other operative documents remain relevant.
Does Dorset's Local Nature Recovery Strategy cover BCP?
Yes. Dorset's published LNRS covers both Dorset Council and BCP Council administrative areas. Dorset Council led its preparation, supported by BCP and Natural England. The strategy was live in December 2025, with a wider launch in March 2026.
Can a mapped Dorset nature recovery opportunity automatically increase my BNG score?
No. The Local Habitat Map identifies potentially useful areas and activities. Strategic significance in the statutory metric still needs a justified relationship with the proposed habitat and current guidance. The map is not a planning approval, site survey or registered biodiversity unit allocation.
What is the difference between Dorset's 0.1ha DBAP and the 0.2ha BNG exemption?
Dorset Council's DBAP can require ecological assessment on sites 0.1 hectares or greater, or where protected species or biodiversity impacts trigger it. Separately, the national 0.2-hectare statutory BNG exemption can apply to qualifying applications made from 6 August 2026 without onsite priority habitat impacts. A site can fall within one process and not the other.
Does Dorset Council's DBAP apply automatically in Bournemouth, Christchurch and Poole?
Do not assume so. BCP Council has its own local validation list, BNG checklist and biodiversity checklist. The correct requirements depend on the actual council, application type and ecological constraints. Dorset Council's DBAP certification and fee arrangements should not simply be copied onto BCP applications.
Are new self-build homes exempt from statutory biodiversity net gain?
Not solely because they are self-build. The previous general exemption for new self-build and custom-build applications was removed from 6 August 2026. Other exemptions or transitional provisions may still apply to a particular project. Check the application date and current national rules rather than relying on an older council form.
Do Dorset Heathlands rules apply to every residential development?
No. The planning framework addresses specific protected heathland areas and relevant development within defined distances, including the 400-metre and 400-metre to five-kilometre zones. Requirements depend on the actual designation, site and current policy. Heathland visitor mitigation or SANG/SAMM is a separate protected-site duty, not simply BNG.
Can I use BNG units instead of Poole Harbour nitrogen mitigation credits?
Not automatically. Poole Harbour nutrient neutrality protects a designated site from additional nutrient pollution. BNG measures separate habitat gains. A nutrient credit or mandatory mitigation measure is not the same thing as a registered off-site biodiversity unit, and legal additionality must be checked carefully.
Can a Dorset landowner create and sell off-site biodiversity units?
Potentially, subject to a credible habitat baseline, feasible habitat proposals, the correct legal securing, registration and subsequent unit allocation. Dorset's LNRS can help identify ecological opportunities but does not guarantee the land is suitable or that units are registered, available or saleable.
When does the Biodiversity Gain Plan need approval?
For planning permission subject to the statutory biodiversity gain condition, the Biodiversity Gain Plan must be approved before development starts. Applicants may still need baseline surveys, metric and ecology evidence earlier for planning validation. The gain plan and any habitat management and monitoring requirements are distinct documents.
Local planning guidance
Discuss your Dorset BNG project
Tell us where the site is, what you are proposing and whether Dorset Council or BCP Council is handling the planning application. A red-line plan, draft layout and any existing ecology information will help identify the appropriate scope.
We can discuss habitat surveys, metric calculations, BNG reports and management requirements relevant to the site. Where protected heathlands, coastal habitats or nutrient constraints matter, we can help identify where separate assessments or specialist advice are needed.
Discuss your Dorset biodiversity net gain requirements
Alternative contact: You can also contact ACP directly.
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
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Dorset BNG
Sources and references
Reviewed 7 November 2026.
Official planning and nature recovery sources
- GOV.UK biodiversity net gain
- current exemptions
- statutory metric tools
- Dorset Council adopted Local Plans
- BCP adopted Local Plan areas
- Dorset Biodiversity Appraisal Protocol
- Dorset Local Nature Recovery Strategy
- Dorset Council Local Plan timetable
- BCP Local Plan timetable
- Dorset Heathlands Planning Framework
- Bournemouth adopted policies and heathland mitigation
- Poole Harbour nutrient neutrality