Guidance

Biodiversity net gain: what local planning authorities should do 

How local planning authorities can ensure that developers and land managers meet the requirements for biodiversity net gain (BNG). 

• From: Department for Environment, Food & Rural Affairs
• Published: 29 November 2023
• Last updated: 28 November 2024 — See all updates

Applies to England

Biodiversity net gain (BNG) is mandatory from 12 February 2024.

You can view all of the BNG guidance in the BNG collection.

There is more detail on what local planning authorities (LPAs) should do in the planning practice guidance.

Read the collected guidance on BNG for developers, land managers and LPAs.

Planning applications and biodiversity gain plans: guidance for LPAs

1. Before granting planning permission

Planning permission includes a statutory biodiversity gain condition. There is more information on BNG and planning in the planning practice guidance.   

What to check

LPAs must check the following have been submitted with the planning application, where development would be subject to the biodiversity gain condition:

• a statement confirming whether the applicant believes that planning permission, if granted, would be subject to the biodiversity gain condition

• the pre-development biodiversity value of the on-site habitat on the date of application (or an earlier date) including the completed metric calculation (showing the calculations, the publication date and version of the biodiversity metric used to calculate that value)

• where the applicant wishes to use an earlier date, the proposed earlier date and the reasons for that date

• a statement confirming whether the biodiversity value of the on-site habitat is lower on the date of application (or an earlier date) because of the carrying on of activities (‘degradation’)

• where unauthorised degradation has taken place between 30 January 2020 and the submission of the planning application, the relevant date should be immediately before these activities were carried out

• a description of any irreplaceable habitat on the land, that exists on the date of application (or an earlier date)

• a plan drawn to an identified scale (including the direction of north), showing on-site habitat existing on the date of application (or an earlier date), and any irreplaceable habitat

Applicants can refer to these details in accompanying documents, rather than duplicate this information within the application form.

In the planning application form, applicants will confirm whether this information accompanies the application.

If this information has not been provided, the LPA must refuse to validate the application.

In addition to these minimum requirements, further information may need to be provided in order to assist the consideration of BNG as part of the planning application. This may include where there are particular considerations around:

• significant on-site biodiversity enhancements
• use of off-site biodiversity gains

LPAs may set out specific further requirements in the local list of information requirements.

It is good practice for developers to submit information about any potential planning obligations. This is something that LPAs may add to local lists of information requirements.

For example, if there may be a need for a significant increase of on-site biodiversity enhancements, developers should provide a draft habitat management and monitoring plan as part of the application. This plan sets out the proposals for long term maintenance of habitats to be secured through planning condition or planning obligation.

If there may be a need for an off-site biodiversity gain site specifically to provide gains for the development, developers should clearly set out the obligations that they are likely to be bound by in a section 106 agreement, if permission is granted.

Checking metric calculations

LPAs are responsible for reviewing and checking metric tool calculations submitted by developers, as part of assessing whether they can achieve 10% BNG. 

The statutory biodiversity metric tool must be used to create the biodiversity gain plan. LPAs should not accept calculations made with previous versions of the metric tool (4.0 and before).

Small developments can choose to use a simpler small sites version of the metric.

LPAs should assess small sites calculations in the same way as calculations made for larger sites using the statutory biodiversity metric tool. LPAs cannot expect a developer to use any specific consultant or ecologist.

Developers should submit a copy of the metric calculation with the planning application as supporting evidence of the habitat’s biodiversity value before development. 

Read guidance about the biodiversity metric.

See all biodiversity metric calculation tools and guides.

Recorded webinars are available from the Local Government Association’s Planning Advisory Service.

Checking habitat surveys  

To review habitat surveys submitted by developers in the BNG process, LPAs may need to check: 

• aerial photos 

• protected sites and species 

• local environmental record centres 

• other data sources 

• with local ecologists or habitat specialists to get their advice  

LPAs only need to check information that’s relevant to the habitat survey. 

Developments for on-site gains within small developments do not need to submit habitat surveys. 

Enter into a legal agreement  

Before LPAs create a legal agreement, they must check:

• that the land manager has the right licences, consents and permits
• that the metric calculation for the habitat before creation and enhancement is accurate
• if the habitat or enhancement is within the wildlife consultation area of an aerodrome and that it does not harm aircraft operations

There is more information on what developers need to agree with the LPA or responsible body.

The local authority (LA) must register the planning obligation or conservation covenant with the local land charges register.

Working with developers who wish to buy statutory biodiversity credits

LPAs should talk to the developer as soon as a potential need for statutory biodiversity credits has been identified. 

LPAs will only allow developers to buy statutory credits as a last resort. This means that despite following the mitigation hierarchy, developers cannot meet the 10% BNG requirement through on-site or off-site gains alone.

When an LPA agrees that a developer can buy statutory credits, they should confirm this by email without delay. This is so that the developer can start the statutory credit purchase process following conditional planning approval.

LPAs must advise developers that they cannot buy statutory credits until they are able to discharge (fulfil) their non-BNG pre-commencement planning conditions. The developer must send a valid decision notice from the LPA to Natural England as soon as they apply to buy statutory credits. Natural England will not process a credits purchase without a valid decision notice.

LPAs should remind the developer to use the unit shortfall summary tab on the statutory biodiversity metric calculation tool. This will help them buy the correct number of credits.

LPAs may need to advise developers on bespoke BNG compensation if they are building on some types of habitats. When developers use the metric tool, it will tell them if they need to make bespoke compensation. They cannot buy statutory biodiversity credits if they are required to make bespoke compensation.

2. Reviewing the biodiversity gain plan

After planning permission has been given, developers can submit their biodiversity gain plan for the LPA to review. The LPA will then need to decide whether to approve the biodiversity gain plan by considering whether the 10% BNG is achieved.

What to check

LPAs should check the biodiversity gain plan explains:   

• how the developer has applied the biodiversity gain hierarchy
• the biodiversity unit values before and after development
• how the developer will deliver the 10% BNG

As part of their biodiversity gain plan, the developer must submit their:

• completed biodiversity metric calculation
• plans for before and after development (showing the location of on-site habitat and the direction of north and drawn to an identified scale)

The final metric calculation showing the value before and after proposed development does not have to be completed until the final biodiversity gain plan is submitted, although it can be shared earlier.

The LPA must assess and decide whether to approve the final biodiversity metric calculation. It is up to the LPA to determine what expertise is needed to help assess the biodiversity metric submitted with the biodiversity gain plan. They may decide to use an ecologist or one of their planning officers.

LPAs need to check that:

• the pre-development, post development and total net change calculations match
• it meets the BNG trading rules (the statutory biodiversity metric user guide explains these rules on habitat compensation)
• the developer’s habitat valuations are accurate

If a small development uses off-site gains in their main biodiversity metric, LPAs need to manually check the trading rules in the biodiversity gain plan.

The developer must also provide any of the following that apply to their application:

• compensation plan if the development impacts irreplaceable habitats
• site’s reference numbers from the biodiversity gain sites register
• proof that they need statutory credits
• statutory biodiversity credits proof of purchase
• habitat management and monitoring plan

There is a biodiversity gain plan template. It is not mandatory, but asking developers to use it could help with standardising the submission of biodiversity gain plan and metric information.

Checking the biodiversity gain sites register for off-site gains 

LPAs should check that the amount and type of any off-site gains listed in the developer’s biodiversity gain plan match the allocation recorded on the biodiversity gain sites register, operated by Natural England.

Before the LPA approves a biodiversity gain plan, it must check that:

• any off-site gains in the plan have been registered
• those off-site gains have been recorded as allocated to the development in question
• the biodiversity value of the gains in the gain plan match the value recorded on the register

Developers do not need to register or allocate:

• on-site gains
• statutory biodiversity credits

How to check the right statutory credits have been purchased

With their biodiversity gain plan, the developer will provide proof of purchase of statutory biodiversity credits, which will state the number of statutory credits of each tier they have bought. 

They will also provide their final metric calculation. LPAs will need to check that the developer has bought the correct number of statutory credits from each price tier, using the unit shortfall summary from their metric calculation.

3. Approving the biodiversity gain plan

LPAs must decide whether to approve a biodiversity gain plan within 8 weeks. LPAs must notify the applicant with the decision.

If the LPA approves the biodiversity gain plan, they must publish the decision on their planning register. 

Developers cannot start work on a development until the LPA has approved the biodiversity gain plan.

LAs must report on biodiversity gains that are delivered and expected to be delivered. Information from biodiversity metric calculations could support the duty to report on biodiversity gains.

Monitoring BNG

The person responsible for ensuring the landowner does what they have committed to do is the other party to the legal agreement. Where a planning obligation secures on-site or off-site gains, the LPA should enforce the agreement. Where on-site or off-site gains are secured by a conservation covenant, the responsible body should enforce the agreement. 

The LPA or responsible body should:

• monitor whether the landowner is meeting their obligations
• take action if they do not

Actions LPAs should take on mandatory biodiversity net gain

Setting local policies to support BNG 

LPAs can set policies to support BNG. They can identify local areas suitable for habitat creation and enhancement to help: 

• landowners who want to sell off-site biodiversity units
• developers who need to comply with the BNG requirements

LPAs can make sure developers know about: 

• the requirement for 10% BNG
• local policy requirements for BNG, such as local nature recovery strategies

If the local nature recovery strategy has not yet been published, LPAs should say what plans are currently in place. 

Local nature recovery strategies identify the places and habitats that are most beneficial for nature and get 15% more biodiversity units in the biodiversity metric than the same habitat created elsewhere.

Find out about biodiversity units in guidance about off-site gains.

Find out about identifying habitat of strategic significance for local nature recovery in guidance about complying with the biodiversity duty.

Facilitating transactions of units between buyer and sellers to support the availability of biodiversity units

LPAs may be able to introduce sellers and buyers to each other by: 

• developing matching services
• providing a habitat bank register that lists local gain sites for sale

This activity is optional but may support the availability of biodiversity units for mandatory biodiversity net gain.

Off-site gains on land owned by an LA 

There are options available to secure LA land using legal agreements (section 106 and conservation covenants).

LAs cannot secure gains using legal agreements with themselves, so they must secure their land in other ways.

Securing LA land using a section 106 agreement

There are options for LAs to secure their land with a section 106 agreement.

1.Special purpose vehicle

The LA can set up a special purpose vehicle and enter a section 106 agreement with them. The special purpose vehicle will carry out the habitat enhancement work and the LA must check that they meet their responsibilities.

2.Enter an agreement with the county or district council

If the LA is not a unitary authority, they can enter a section 106 agreement with the county council. The LA will carry out the habitat enhancement work and the county council must check that they meet their responsibilities.

3.Lease the land to a tenant

The LA can lease their land to a tenant and enter a section 106 agreement with them. The tenant will carry out the habitat enhancement work and the LA must check that they meet their responsibilities.

Securing LA  land using a conservation covenant agreement

There are options for LAs to secure their land with a conservation covenant agreement:

1.The LA carries out the habitat enhancement works

Enter an agreement where the LA will carry out the habitat enhancement work and the responsible body must check that they meet their responsibilities.

2.The responsible body carries out the habitat enhancement works

Enter an agreement where the responsible body will carry out the habitat enhancement work and the LA must check that they meet their responsibilities.

3.The tenant carries out the habitat enhancement works

The LA can lease their land to a tenant and enter an agreement with them. The tenant will carry out the habitat enhancement work and the LA must check that they meet their responsibilities.

The LA must register the planning obligation or conservation covenant with the local land charges register.

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Published 29 November 2023
Last updated 28 November 2024 + show all updates

1. 28 November 2024

   Updated the section 'Working with developers who wish to buy statutory biodiversity credits.'

2. 8 May 2024

   Amended link to biodiversity gain sites register.

3. 23 February 2024

   Added that the statutory biodiversity metric user guide explains the BNG trading rules on habitat compensation.

4. 12 February 2024

   Updated box at top of page to state that biodiversity net gain (BNG) is mandatory from 12 February 2024 and removed the 'draft guidance' label. Restructured and made changes throughout, including clarifying the LPA's duties throughout the planning application process and when reviewing and approving biodiversity gain plans, and the use of LPA and LA.

5. 1 December 2023

   Added link to aerodrome information.

6. 29 November 2023

   First published.