Biodiversity net gain (BNG) is a way of creating and improving natural habitats. Developers must deliver a BNG of 10%. This means a development will result in more or better quality natural habitat than there was before development.
In England, BNG is now a national requirement set by government and is mandatory from:
- 12 February 2024 for major developments
- 2 April 2024 for all minor and other applicable application
under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021)
Cornwall Council been requesting Biodiversity Net Gain information on major applications since 1 March 2020 as a local requirement.
The below guidance has been put together to help planning applicants and agents:
- know when BNG information is required
- what information is required
Please note that even if you think an application is exempt, some level of information may be required. This is covered in the below guidance.
This guidance should be read in conjunction with the Cornwall Council Validation Guide.
Mandatory Biodiversity Net Gain
Mandatory Biodiversity Net Gain is a national requirement. It is required for all major and minor applications including outlines.
Information needed where Mandatory Biodiversity Net Gain is required
The application must be accompanied by minimum information set out in Article 7 of The Town and Country Planning (Development Management Procedure) (England) Order 2015:
- a statement as to whether the applicant believes that planning permission, if granted, would be subject to the biodiversity gain condition;
- the pre-development biodiversity value of the onsite habitat on the date of application (or an earlier date) including:
- the completed metric calculation tool used 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 proposing that date;
- a statement confirming whether the biodiversity value of the onsite habitat is lower on the date of application (or an earlier date) because of the carrying on of activities (‘degradation’). In which case the value is to be taken as immediately before the carrying on of the activities. If degradation has taken place there must be supporting evidence of this;
- a description of any irreplaceable habitat (as set out in column 1 of the Schedule to the Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations [2024]) on the land to which the application relates, that exists on the date of application, (or an earlier date); and
- a plan, drawn to an identified scale which must show the direction of North. Showing onsite habitat existing on the date of application (or and earlier date). As well as including any irreplaceable habitat.
Biodiversity statement
The Biodiversity Net Gain Statement is a local requirement and only required on major applications. It supports the Council’s Environmental Growth Strategy which aims to not just conserve, but to grow nature.
The statement requests additional information to the information provided under the national requirements.
Information regarding each is set out in the Validation Guide.
Information needed where a Biodiversity Net Gain Statement is required
A BNG Statement shall be submitted setting out:
- The expected post-development on-site habitat. This includes the completed metric calculation tool used showing the calculations. As well as the publication date and version of the biodiversity metric used to calculate that value.
- The likely quantum of off-site gains/use of statutory biodiversity credits required
- The justification for any off-site gains/statutory biodiversity credits required. Taking account of the Biodiversity Gain Hierarchy.
- Any significant onsite habitat enhancements. Along with detailed proposals of these habitat enhancements as part of the plans, drawings and supporting information.
- Draft Habitat Management and Monitoring Plan which sets out the proposals for the long-term maintenance of any significant onsite habitat enhancements and off-site gains.
- Draft heads of terms for any obligations that are likely to be bound by a section 106 agreement
Exemptions
Biodiversity does not apply to:
- retrospective planning permissions made under section 73A; and
- section 73 permissions where the original permission which the section 73 relates to was either granted before 12 February 2024. Or the application for the original permission was made before 12 February 2024
- Planning permissions which have been granted through other routes to permission, including:
- Local Development Orders
- Simplified Planning Zones
- Neighbourhood Development Orders
- Successful enforcement appeals
- Deemed planning permission
- Permission in Principle applications
- Householder development
- Development subject to the de minimis exemption
- Self-build and custom build development. A self-build or custom build housing proforma will need to be completed for all applications for custom and self-build housing.
- Urgent Crown development granted permission under section 293A of the Town and Country Planning Act 1990
- Development of a biodiversity net gain site
- Development related to the high speed railway transport network.
Only one exemption can be applied per application.
Further information can be found in:
Government Guidance - Biodiversity Net Gain
We are currently experiencing issues where either:
- An exemption is stated on the application form however no justification or evidence is provided why this exemption applies. In these cases the application cannot be validated until justification is received; or
- An exemption is stated on the form but later found the exemption does not apply. This results in the application being invalid until the necessary BNG information is provided.
Both cause delays in the planning process. Applicants and agents are advised to:
- Ensure justification is provided on the form why the exemption applies. For example ‘de minimus’ is not enough information to validate the application. Further information will be requested.
- Check that the exemption does apply.
Types of applications
All major and minor applications including outlines require Biodiversity Net Gain. Further information regarding specific application types can be found below.
Outline Applications
National Minimum information requirements – required at outline.
Outline applications (including phased) may not know the exact details of how biodiversity net gain will be achieved at the point of submitting an application. However, they must demonstrate that they have an approach as to how they will deliver it. There should be evidence that the BNG hierarchy has been followed and this should be used to justify decisions.
A BNG Statement (Local requirement) is required where seeking approval of layout and/or landscaping. This may be at the outline or reserved matters stage.
Variation/Removal of Condition Applications
BNG (national and local requirements) not required.
Section 73A (retrospective applications)
At the present time BNG is not required on retrospective applications.
DLUHC are bringing BNG for retrospective permissions as the second part of the implementation of BNG.
Permission in Principle (PiP) Applications
There is no requirement for BNG (local or national requirements) on PiP applications.
The BNG requirement will be dealt with at the Technical Details Consent stage where both the local and national requirements apply as per a normal application for major or minor development.
Change of use applications with no operational development
BNG must be considered however it is likely an exemption applies.
Amending an existing permission
If the changes are so significant that they can’t be dealt with under:
- a non-material amendment or
- variation/removal of condition application
it is likely the change will have an effect on the BNG calculations. Therefore the BNG requirements apply.
Reserved matters
National Minimum information requirements:
For both major and minor development the national requirements will have been provided at the outline stage.
We will process RMs where the national requirements were not provided at outline. i.e. where the outline application was submitted prior to the implementation of the national requirements. We will not require this information retrospectively at the RM stage.
BNG Statement (Local requirement):
For major developments, the local requirement will apply where the applicant is seeking approval of Landscaping and/or Layout reserved matters. This may be at the outline or reserved matters stage.
Appeals
Appeal a biodiversity gain plan (s78) decision: How to appeal to the Secretary of State if the Local Planning Authority refuse or fail to determine the biodiversity gain plan.
You can find out how to complete the form at: Biodiversity Gain Plan: how to complete your appeal form
Metric guidance and tools
View the statutory biodiversity metric tools and guidanceSmall Sites Metric
The small sites metric can only be used when the site does not meet the definition of a major development.
To use the small sites metric the development must be:
- residential development where the number of dwellings is between 1 and 9 on a site of an area 1 hectare or less. Or if the number of dwellings is unknown, the site area is less than 0.5 hectares, or
- commercial development where floor space created is less than 1,000 square metres or total site area is less than 1 hectare, or 8
- development that is not the winning and working of minerals or the use of land for mineral-working deposits, or
- development that is not waste development
Additionally, not all small sites can use the small sites metric. If there is habitat present onsite which is not in the small sites metric, this means that the full statutory metric must be used. Similarly, the small sites metric cannot be used if the site lays within a statutory protected site. Or if there is statutory protected habitat, priority habitat or European protected species on site.
Further clarification can be found on pages 7 and 8 of the small site metric user guide.
Versions of the metric
We are unable to accept any previous versions of the metric 4.0 or before.
Applicants/agents must use the statutory biodiversity metric tool.
If you have used an older version of the metric you can copy and paste across the metric. Guidance regarding this can be found on the Government web page - Statutory biodiversity metric tools and guides.
How to submit the metric
The metric must be submitted through the planning portal using the right file type. The metric must have all sheets unhidden and be saved as a macro disabled excel file (.xlsx). It must be less than 10MB. If you have any issues with this, please email the metric to planning@cornwall.gov.uk. quoting the Planning Portal reference number.
BNG Sites
A BNG site is a site where the main purpose is to be used to fulfil the delivery of biodiversity units for biodiversity net gain.
If a developer cannot fulfil BNG on-site they can use units on land elsewhere (as long as the correct procedure is followed). These units are called off-site. A habitat bank would be an example of the BNG gain site. They are sites where the main purpose is to be able to provide these ‘off-site’ units to developments.
Read the full definition in the Biodiversity Gain Requirements (Exemptions) Regulations 2024.
On-site and off-site BNG
Anything which is included in the red-line boundary is considered on-site. Anything that is outside of the red-line boundary is considered off-site. If a landowner has additional land which is:
- in their blue line boundary
- but not in their red line boundary
they can use this to provide biodiversity units. However, it would need to be registered in line with the process for using off-site gains.
Old application forms which don’t include BNG questions
The application must be submitted on an update form which includes the BNG questions.
Forms can be downloaded from the Planning Portal should you wish to submit your application as a hard copy.
Degradation in BNG
The BNG metric requires the baseline to be filled in for the time of application to reflect what is currently on site, but an earlier date can be agreed with the LPA in certain cases.
If any degradation has occurred on site, then the applicant will need to agree an earlier date to take into account the degradation. The statutory metric user guides says this for filling in the baseline:
‘Accounting for degraded sites if a habitat has been cleared, destroyed or degraded previously, and you should use an earlier baseline, you must:
- use the pre-degradation habitat type as the site’s baseline
- evidence how this habitat type and condition has been determined in the user comments
- record the habitat as lost within the biodiversity metric tool
- account for the time between the habitat loss and compensation using the ‘delay in starting habitat creation or enhancement’ function
You can use data records, imagery and historic field surveys to determine predegradation habitat types. Use a precautionary approach when assigning condition scores. For example, assign a higher condition score in the absence of contrary evidence.’
Information required
- 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)
- if 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
Within the BNG Plan, the applicant must provide a reference for the agreed date.
BNG Condition/BNG Plan
The biodiversity gain condition has its own separate statutory basis, as a planning condition under paragraph 13 of Schedule 7A of the Town and Country Planning Act 1990.
It will not be included as a separate condition in the list of conditions. It will be provided separately to the conditions as an informative.
A Biodiversity Gain plan is required to be submitted to and approved in writing before any development starts on site.
The plan will set out how the biodiversity gain objective of at least 10% will be met.
The plan must be submitted in writing, no earlier than the day after planning permission has been granted.
There is a standard biodiversity gain plan template available to assist.
The plan must be submitted via the Planning Portal as a discharge of condition or hard copy. We will not accept email submissions. It must be accompanied by the discharge of condition form and relevant fee.
BNG Plan Reference
Within the BNG Gain Plan (question 4.18), the applicant must provide a reference for the agreed date. The BNG pre-application service can be used to agree what habitat has been lost or degraded to establish the baseline date and value of the site. The pre-application number can then be used as the reference number in the BNG Gain Plan.