Buckinghamshire BNG / County planning guidance
Biodiversity net gain in Buckinghamshire starts with your site, its habitats and the correct planning area. One council uses four legacy local plans. This guide connects those policies with habitat evidence, nature recovery and practical delivery.
ACP helps developers, architects, planners and landowners scope habitat surveys, calculate biodiversity units and prepare planning evidence. We can also advise on Biodiversity Gain Plans and long-term habitat management.
Reviewed 8 November 2026 · Buckinghamshire and Milton Keynes LNRS published autumn 2025
10% objective / application dates / exemptions
Eligible development across Buckinghamshire normally needs at least 10% statutory Biodiversity Net Gain. National BNG rules apply, while local planning policy can affect other ecological evidence and design expectations.
The law changed on 6 August 2026. For qualifying new applications, a site of 0.2 hectares or less can be exempt. This applies where no onsite priority habitat is affected. Some wholly temporary developments lasting no more than five years may also qualify. The former dedicated self-build and custom-build exemption ended for new applications made from that date.
These exemptions have conditions and transitional provisions. A small red-line boundary is not proof of exemption by itself. Older applications, section 73 permissions and other exempt development types require the correct legal route.
Even where mandatory BNG does not apply, a project may affect protected species, important trees, ancient woodland or designated sites. Those duties are separate.
Read our BNG exemptions guide or consult the current government exemptions guidance.
Four legacy plans / separate Milton Keynes authority
Buckinghamshire Council was established in April 2020. It replaced the former Buckinghamshire County Council and four district authorities. Nevertheless, the legacy district development plans still guide decisions in their former areas.
Milton Keynes City Council is a separate unitary planning authority. The joint Buckinghamshire and Milton Keynes Local Nature Recovery Strategy does not merge their planning powers.
| Planning area | Current adopted planning framework | What to check for BNG |
|---|---|---|
| Aylesbury Vale — north and central Buckinghamshire | Vale of Aylesbury Local Plan, adopted 2021. NE1 addresses biodiversity and geodiversity. | Site habitat surveys, local wildlife networks, development-site policies and the current Buckinghamshire validation checklist. |
| Chiltern — east Buckinghamshire | Chiltern Local Plan adopted 1997 and Chiltern Core Strategy 2011. CS24 covers biodiversity. | Chilterns landscape and woodland habitats; protected species and locality-specific adopted policies. |
| South Bucks — south Buckinghamshire | South Bucks Local Plan adopted 1999 and Core Strategy 2011, including CP9 biodiversity. | Burnham Beeches SAC and relevant Habitats Regulations mitigation, ecological surveys and local policy. |
| Planning area | Current adopted planning framework | What to check for BNG |
|---|---|---|
| Wycombe — west Buckinghamshire | Wycombe Local Plan adopted 2019, including DM34 green infrastructure and biodiversity, plus 2013 Delivery and Site Allocations Plan and DM14. | Local green-infrastructure requirements, potentially tree canopy calculations, nearby watercourses and qualifying SAC mitigation. |
| Buckinghamshire Council — countywide minerals/waste | Buckinghamshire Minerals and Waste Local Plan to 2036, adopted 2019. | Check the actual application route and appropriate development-plan policies; not a separate council. |
| Milton Keynes City Council | Plan:MK, adopted 20 March 2019, with biodiversity and green infrastructure policies including NE1–NE4. Separate 2021 Biodiversity SPD. | Use Milton Keynes planning validation, ecology evidence and any applicable monitoring arrangements; not Buckinghamshire Council's local checklist. |
The proposed Chiltern and South Bucks Local Plan to 2036 was withdrawn. It is not an adopted replacement for the older plans.
For Buckinghamshire Council, start with the official current development-plan register. For Milton Keynes, consult planning-policy guidance.
Adopted plans / emerging NE6 / national policy
No. Buckinghamshire Council consulted on its proposed Local Plan to 2045 during 2026. The main Regulation 19 consultation ran from 23 July to 6 September 2026, with some evidence-document consultation extensions to 20 October.
As at 8 November 2026, the plan had not been adopted. The existing adopted plans continue to matter. The draft is useful for seeing policy direction, but it is not a new blanket statutory requirement.
The Regulation 19 draft NE6 — Biodiversity gain and nature recovery proposes different percentages depending on how gain is delivered.
| Route in the draft policy | Draft NE6 figure | Status on 8 November 2026 |
|---|---|---|
| Qualifying gain delivered onsite | 10% | Emerging policy proposal, not adopted |
| Registered off-site gain delivered within Buckinghamshire | 10% | Emerging policy proposal, not adopted |
| Registered off-site gain delivered outside Buckinghamshire | 20% | Emerging proposal, subject to newer national policy and plan examination |
These emerging targets do not establish an adopted countywide requirement or a charging scale.
The earlier Regulation 18 draft NE5 used a different proposal. Use the current Regulation 19 NE6 text when considering the emerging plan.
National policy N1(2) restricts development-plan BNG standards above the statutory objective to specific site allocations, where fully justified and deliverable. Policy N2(3) directs decision-makers not to give weight to other higher-than-statutory local requirements.
Consequently, the draft 20% figure for gains outside Buckinghamshire raises an important policy-consistency question. It is not appropriate to assume that all projects must meet it, nor to claim the council has already abandoned the proposal.
Before fixing a higher target, check the adopted development plan, site allocation, application date, latest national policy and any subsequent Local Plan examination changes.
Read the Buckinghamshire Regulation 19 consultation and the 2026 NPPF natural-environment policies.
Plan:MK / separate validation / council monitoring
Milton Keynes shares the Local Nature Recovery Strategy with Buckinghamshire but has its own Local Plan, validation process and planning authority.
Its adopted Plan:MK dates from March 2019. A Biodiversity Supplementary Planning Document was adopted in June 2021. Read its local requirements alongside current national legislation.
The proposed MK City Plan 2050 was submitted for examination on 22 April 2026. Hearings began in September 2026, and the plan remains under examination in November 2026.
If your site is in Milton Keynes, do not rely on Buckinghamshire Council's former-area policy table, new draft NE6 figures or validation instructions. Use the city council's operative plan and specific submission requirements.
Milton Keynes also publishes details of its BNG monitoring fee arrangements. These relate to specified council monitoring responsibilities, not the price of consultancy surveys or biodiversity units. The actual charge and qualifying conditions should be confirmed directly with the council.
Official links: Milton Keynes BNG guidance and MK City Plan 2050.
Published autumn 2025 / Local Habitat Map
The Buckinghamshire and Milton Keynes Local Nature Recovery Strategy (LNRS) was approved for publication by Buckinghamshire Council in October 2025 and published later that autumn.
The strategy covers both Buckinghamshire Council and Milton Keynes City Council areas. It contains a written statement of nature-recovery priorities and a Local Habitat Map.
The map distinguishes existing important areas for biodiversity, places that could become important through restoration, and potential habitat measures. These layers help identify where ecological work might deliver stronger landscape-scale benefits.
However, an opportunity map is not a field survey. Nor does it guarantee that a habitat bank will be registered or that a developer can claim a particular number of biodiversity units.
The metric's strategic significance should reflect the appropriate published LNRS measures and current statutory rules. A higher score requires a suitable proposed habitat intervention and geographic evidence. It does not arise automatically because the site lies inside a broad nature-recovery area.
For example, restoring grassland or wetland in the correct mapped location may align with a strategic action. However, habitat condition, delivery difficulty, trading rules and management still need assessment.
Explore the Buckinghamshire and Milton Keynes Nature Recovery Strategy and the official interactive Local Habitat Map.
Chilterns / river networks / Burnham Beeches
The Chilterns National Landscape contains chalk habitats, wooded valleys and landscape-scale wildlife networks. These require sensitive design and protection of existing habitat value.
The Chilterns designation is not a separate planning authority. Buckinghamshire Council decides applications within its area, subject to applicable national and local policies.
River Thame, Upper Ray and Colne catchments, floodplain meadows and local chalk-stream systems may create valuable habitat restoration opportunities. However, water quality, hydrology, soil conditions, flood risk and existing ecology constrain suitable options.
Where a development affects a river or stream, an appropriate river condition assessment may be required alongside the watercourse metric module.
Development near Burnham Beeches SAC may require separate Habitats Regulations Assessment and recreation mitigation. Depending on the relevant location and proposal, this can include strategic access management and monitoring (SAMM) or suitable alternative natural greenspace (SANG).
These are not biodiversity units. Buying off-site units or achieving 10% BNG does not remove any Habitats Regulations duty.
Bats, breeding birds, great crested newts, badgers, reptiles, ancient woodland, mature trees and hedgerows can require distinct survey and avoidance measures. A legal BNG exemption does not automatically waive those protections.
Habitat creation may also interact with archaeology, land capability and nutrient-rich soils. Consequently, the best planting or restoration option depends on the site, not just an attractive target habitat in the metric.
Retain important existing habitats and prevent avoidable harm. Establish realistic delivery capacity before calculating an off-site shortfall.
A practical project brief / seven checks
Use this original worksheet before commissioning a final metric or submitting planning information. It helps organise the evidence for a site-specific assessment.
| Check | What to record | Why it changes the next step |
|---|---|---|
| 1. Correct authority | Site boundary, Buckinghamshire Council legacy planning area or Milton Keynes | Identifies the current adopted plan and local validation list. |
| 2. Application and exemption | Submission date, major/non-major status, red-line site area, priority habitats | Establishes the correct national BNG route and transitional rules. |
| 3. Existing ecological baseline | UKHab habitats, condition, hedgerows, watercourses, trees and species | Defines survey and statutory metric requirements. |
| 4. Other protected-site duties | Burnham Beeches SAC, ancient woodland, species and watercourses | Identifies separate Habitats Regulations and ecological constraints. |
| 5. LNRS map and habitat action | Local Habitat Map, potential measures and matching proposed habitat | Tests strategic significance and nature-recovery fit. |
| 6. Policy target | Current adopted legacy or Milton Keynes plan, relevant site allocation, draft NE6 only as emerging | Prevents treating a proposed 20% off-county rule as adopted law. |
| 7. Delivery and management | Onsite space, registered off-site options, legal security, 30-year responsibilities | Indicates the likely gain-plan and habitat management work. |
Your practical conclusion: “We know the planning authority, statutory BNG position, baseline survey needs, local habitat opportunity and delivery route.” If a key answer is uncertain, investigate it before finalising a habitat target.
Baseline evidence / local validation / gain-plan stage
For eligible development, national application-stage requirements ordinarily include:
The council may also need proportionate ecological evidence based on the site, development type and its published local validation checklist.
Buckinghamshire Council provides ecology and trees screening guidance. Where its checklist indicates a need, ecological survey information may be required. The relevant adopted biodiversity policy depends on the former Aylesbury Vale, Chiltern, South Bucks or Wycombe planning area.
Milton Keynes has a separate application and validation route. Do not submit the Buckinghamshire checklist as if it were the Milton Keynes local list.
The final Biodiversity Gain Plan is normally submitted after permission and approved before development starts. It should not automatically be described as a national initial application validation document.
For detailed scope, see our BNG assessment service, BNG survey service and Biodiversity Gain Plan guide.
Habitat condition / strategic significance / statutory tools
The statutory biodiversity metric compares the baseline and proposed biodiversity values. It considers habitat type, area or length, condition, strategic significance and delivery risk. Hedgerows and watercourses can require separate metric modules.
As at 8 November 2026, the current government statutory biodiversity metric was version 1.1.0, updated 3 November 2026. Some smaller eligible developments can use the Small Sites Metric, but application type and habitat eligibility matter.
The joint LNRS can inform the strategic significance assessment. However, a mapped nature-recovery measure must be relevant to the proposed intervention. A map cannot substitute for UKHab fieldwork or condition assessment.
Our statutory biodiversity metric service explains the calculation process. Also see Small Sites Metric assessments if your project may qualify.
Gain hierarchy / registered sites / 30-year management
Potentially. Registered off-site units can help meet a shortfall where the scheme complies with the current rules and the gains are legally secured.
For major development, the gain hierarchy still prioritises appropriate onsite habitat improvements before registered off-site units. For eligible non-major applications submitted from 6 August 2026, onsite and registered off-site options may be treated at an equivalent level. Statutory credits remain the last option.
The legal arrangements must secure required habitat delivery, management and monitoring for at least 30 years where significant onsite or registered off-site gains apply.
Buckinghamshire Council publishes examples of habitat gain sites with legal agreements, including Holtspur Farm, Ludgershall Meadows, Lopemede Farm, Manor Farm, Pickeridge Farm and Valley Farm.
These are useful local examples. However, listing a gain site does not prove its current units are available, allocated to your project or priced at a particular amount. Check the biodiversity gain sites register, habitat types and the relevant trading and spatial rules.
Read our off-site biodiversity units guide and Habitat Management and Monitoring Plan service.
Survey fees / habitat delivery / separate SAC mitigation
Different project payments are not interchangeable.
| Potential cost | Purpose | What it is not |
|---|---|---|
| Habitat survey and metric | Ecological survey, condition assessment and unit calculation | Not an automatic council tariff or unit price. |
| Registered off-site units | Securing eligible biodiversity gains elsewhere | Not a substitute for other protected-site mitigation. |
| HMMP and monitoring | Long-term habitat management and authority oversight where relevant | Not necessarily included in the original ecology survey quotation. |
| Burnham Beeches SAC mitigation | Habitats Regulations mitigation, such as qualifying SAMM/SANG arrangements | Not statutory BNG units. |
| Milton Keynes BNG monitoring fee | Council monitoring of qualifying significant habitat enhancement | Not the charge for buying units or commissioning ACP. |
For example, Buckinghamshire Council published a 2026/27 SAMM charge of £2,233.24 per dwelling for applicable Burnham Beeches SAC development, effective 30 July 2026. This is a specific Habitats Regulations mitigation payment, not a universal Buckinghamshire or BNG fee.
Milton Keynes also publishes distinct BNG monitoring fees. A smaller significant onsite scheme may qualify for a £2,500 fixed monitoring fee. Its criteria include fewer than 10 trees, less than 0.5 km of hedges and no more than 0.5 low/medium-distinctiveness habitat or hedgerow units. All relevant conditions must apply; other proposals use the council’s fee matrix. Confirm all eligibility conditions and current charges directly with the council.
For project budgeting, see BNG costs and pricing. A useful fee estimate requires actual site and proposed habitat details.
Gain sites / floodplain recovery / recreation mitigation
The council’s published examples show several routes for habitat delivery and protected-site mitigation.
Holtspur Farm, Beaconsfield. Buckinghamshire Council lists Holtspur Farm among gain sites with legal agreements. Its presence demonstrates an established local habitat-delivery mechanism. It does not establish how many units remain available to purchase.
Ludgershall Meadows and Lopemede Farm. Council listings identify these sites in the Upper Ray and River Thame landscapes. They show how local wetland and floodplain recovery may form part of long-term BNG arrangements. However, actual habitat value, unit mix and future monitoring evidence remain site-specific.
Little Marlow Lakes and Burnham Beeches SAC. Buckinghamshire Council has progressed suitable alternative natural greenspace proposals linked to strategic mitigation for relevant development, including the Hollands Farm allocation. That is a protected-site recreation mitigation example, not a biodiversity gain-site unit calculation.
These examples show why BNG, protected-site mitigation, local nature recovery and planning obligations must be considered together without confusing their legal purposes.
Sources: Buckinghamshire BNG information and gain sites and Burnham Beeches SAC development guidance.
Confirm the route / gather evidence / plan delivery
Step 1 — Confirm the route. Share the site location, red-line plan, intended works, application type and timescale. We identify the appropriate statutory and local planning context.
Step 2 — Establish the evidence. We scope the habitat survey, condition assessment, metric and separate ecology questions. Where relevant, we also consider the published LNRS map and protected-site constraints.
Step 3 — Plan a feasible gain. We help assess onsite opportunities, potential off-site shortfalls and management needs. The aim is clear ecological evidence for your planning team and gain-plan stage.
Early advice can help limit avoidable redesign and survey-season delays. The scope depends on your site, habitats and application route.
For regional context, explore BNG in South East England. You can also read about our BNG reporting service.
Practical answers / project planning
Statutory BNG normally requires 10% for eligible development across England, including Buckinghamshire. However, exemptions and application-date transition rules apply. Local ecological policies can still require separate survey evidence.
No. For relevant applications made from 6 August 2026, a site at or below 0.2 hectares can qualify only where no onsite priority habitat is affected and other legal conditions are met. Earlier applications may follow different rules.
Not under an adopted countywide 2026 Local Plan policy. Draft Regulation 19 NE6 proposed 20% for gains delivered outside Buckinghamshire. It was not adopted on 8 November 2026, and the September 2026 NPPF restricts higher local BNG requirements.
No. Milton Keynes City Council is its own unitary planning authority with adopted Plan:MK and separate validation requirements. Both authorities share a Local Nature Recovery Strategy, but that does not combine their planning policies.
Aylesbury Vale generally uses the Vale of Aylesbury Local Plan adopted in 2021. Former Wycombe areas use the Wycombe Local Plan adopted in 2019 and relevant 2013 policies. Confirm the red-line boundary and all applicable policies.
No. The strategy identifies nature-recovery priorities and mapped opportunities. The statutory metric is a separate calculation tool. The LNRS can inform strategic significance when the proposed habitat action meets the current metric rules.
No. The intervention must meet the relevant mapped potential measure and statutory metric conditions. Habitat type, condition, risk and other rules also affect the outcome.
No. Habitats Regulations Assessment and recreation mitigation are separate from BNG. An eligible development may need both appropriate SAC mitigation and statutory BNG evidence.
Potentially. Buckinghamshire Council lists gain sites with legal agreements. However, availability, unit types, registration, allocation and prices must be checked for the actual project. A published site listing is not a quotation.
The current statutory metric on 8 November 2026 was version 1.1.0, updated 3 November 2026. Confirm the tool version and relevant assessment guidance when preparing a submission. Some eligible smaller schemes can use the Small Sites Metric.
National minimum BNG information normally accompanies eligible applications. The final gain plan is usually approved after planning permission and before development commences. A local authority may also request proportionate supporting ecology information.
Send the site postcode or plan, red-line boundary, proposed development, existing ecological surveys and application deadline. Tell us whether the site is in Buckinghamshire Council's area or Milton Keynes. 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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Buckinghamshire BNG
Reviewed 8 November 2026.
