Biodiversity Net Gain

Biodiversity Net Gain (BNG) is an approach to development that seeks to leave the natural environment in a measurably better state than it was before development occurred.

Mandatory biodiversity net gain commenced under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021) for major development on the 12 February 2024 and for ‘small site’ development on 2 April 2024. Every grant of planning permission, subject to some exceptions, is deemed to have been granted subject to meeting the biodiversity gain objective of at least a 10% increase in biodiversity value, quantified using Defra’s statutory biodiversity metric. The statutory BNG framework is distinct from other existing environmental legislation.

Exemptions

There are some types of exempted development, and certain types of permission where the legal BNG requirement does not currently apply:

• permissions relating to applications made before the date of commencement for mandatory BNG i.e., 12 February 2024 (or for small sites, 2 April 2024) (however please note these will still be subject to the requirement for BNG set out in some Neighbourhood Plan policies).
• section 73 permissions where the original permission which the Section 73 application relates to was either granted before 12 February 2024 or the application for the original permission was made before 12 February 2024 (or for small sites, 2 April 2024).
• retrospective planning permissions made under section 73A.
• ‘De minimis’ development that does not impact a priority habitat and impacts an area of non-priority onsite habitat less than 25m², or 5m for linear habitats i.e., hedgerows and watercourses.
• householder applications as defined within article 2(1) of the Town and Country Planning (Development Management Procedure) (England) Order 2015.
• self-build and custom-build development where these consist of no more than 9 dwellings, occur on a site area no larger than 0.5ha and it consists only of self-build and custom housing as defined in section 1(A1) of the Self-build and Custom Housebuilding Act 2015.
• biodiversity gain sites - developments undertaken for the purpose of fulfilling the BNG planning condition for another development are exempt.
• permissions granted through a development order under section 59 (includes permitted development rights).
• urgent Crown development (granted under 293A of the Town and Country Planning Act 1990).

Other types of permission that are not subject to the BNG requirement include:

• reserved matters approvals (these are not applications for permission, the BNG requirement is attached to the original outline permission)
• permissions in principle (but the subsequent technical details consent would be subject to the general biodiversity gain condition)

Mandatory biodiversity net gain has not been commenced yet for planning permissions granted through other routes, including local development orders, neighbourhood development orders, successful enforcement appeals and deemed planning permission.

What to include with a Planning Application

Applications should be supported by information to enable the Council to make a full consideration as to whether the general condition is capable of being successfully discharged. For developments subject to BNG, the Planning Practice Guidance stipulates a statutory minimum level of information, set out below:

• 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 on-site 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, and if degradation has taken place 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).
• A plan, drawn to an identified scale which must show the direction of North, showing onsite habitat existing on the date of application (or an earlier date), including any irreplaceable habitat.

Further information regarding validation requirements can be found here.

In line with Planning Practice Guidance, the Council may request further information at determination stage where necessary to help assist the Council in its assessment of BNG proposals in light of existing local policy requirements, and to provide confidence that the BNG objective can be satisfactorily discharged.

The Council encourages applicants to engage with its pre-application service to ensure any potential issues are identified, understood and resolved early on in the process, to reduce any future delay and improve the quality of a proposal.

Biodiversity Net Gain (BNG) Plan Condition 

When a development is subject to Biodiversity Net Gain provisions, every grant of planning permission will be subject to a mandatory pre-commencement condition that requires the approval of a Biodiversity Gain Plan before construction commences.

Applicants should refer to the planning practice guidance and Defra BNG statutory guidance for further detail on all statutory requirements.

Where the on-site BNG provision is considered to be ‘significant’ and for all off-site provision that is not already subject to a s106 agreement or a conservation covenant, the Council is required to monitor the sites to ensure the provision and establishment of BNG for a period of 30 years. Monitoring will be through the submission of Habitat Management and Monitoring Plans.

BNG Monitoring Fees

*Negotiable, dependent on the wider suite of s106 contributions.

Biodiversity Gain Plan (BGP) Requirements

For the Biodiversity Gain Plan requirements, please refer to Town and Country Planning Act 1990, Schedule 7A amended by the Environment Act Sch 14.

In summary, the Biodiversity Net Gain (BNG) plan must achieve a minimum biodiversity net gain of 10% and should typically include the following:

• Steps taken or to be taken to minimise adverse effects of the development on the biodiversity of the on-site habitat and any other habitat.

• Pre-development and post-development biodiversity assessments of the on-site habitat.

• Allocation of any registered offsite biodiversity gain to the development and its biodiversity value in relation to the development

• Details of any biodiversity credits purchased for the development.

Ways to achieve 10% BNG may include:

1. Enhancement and restoring biodiversity on-site (within the red line boundary of a development site).

2. If proposals can only achieve part of their BNG on-site, they can deliver through a mixture of on-site and off-site. Developers can either make off-site biodiversity gains on their own land outside the development site or buy off-site biodiversity units on the market as close as possible to the site.

3. If developers cannot achieve on-site or off-site BNG, they must buy statutory biodiversity credits from the government. This must be a last resort. The government will use the revenue to invest in habitat creation in England.

The Council is responsible for ensuring that the biodiversity gain objective is achieved, whether it be on site, offsite, or through the purchase of credits, and that it is secured by legal agreement as necessary.  It is essential to highlight that planning conditions operate within a strict timeframe. Therefore, any legal agreements required to secure the biodiversity gain must be completed prior to the submission of the discharge of condition application.

Biodiversity Gain Plan Template

BNG Best Practice Process

Future Homes Hub and the Planning Advisory Service have developed a BNG Process Flow Diagram to provide guidance on the steps required to implement BNG on residential projects of all sizes and complexities. The steps within the Process Flow are intended to be used as the basis for parties to apply their project-specific flows, including any evolving internal good practices for implementing BNG.