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What is Biodiversity Net Gain

Biodiversity Net Gain (BNG) is an approach to development which leaves biodiversity in a measurably better state than before the development occurred.

BNG should be considered from the site selection stage through to the final design.

Following completion of the development the habitat delivery will need to be managed for 30 years.

An advisory note for developments delivering BNG in Bristol will follow by end of February 2024.

Changes to biodiversity planning regulations

February 2024 changes: major developments

From 12 February 2024, under the Environment Act 2021, all planning permissions for major developments granted in England, with a few exemptions, will have to deliver a minimum 10% Biodiversity Net Gain.

April 2024 changes: small sites

From 2 April 2024 there must be a 10% mandatory net gain for small sites . For residential developments, small sites are defined as developments between 1 - 9 dwellings, on a site of less than one hectare, or any site less than 0.5 hectares.

Required BNG documents and data for planning applications

Guided by national and local policy, how that 10% will be delivered is an important part in the determination of a planning application.

Below outlines documents and data which will be required as part of the planning application for all non-exempt applications.

All exempt applications will need to provide a statement to support why they consider the proposed development to be exempt from the requirement to deliver BNG .

At planning determination stage (full planning application)

The documents and data you must supply at the planning determination state are:

1: Biodiversity Net Gain Report

A biodiversity net gain report for the purposes of planning will need to accompany the statutory metric provided.

The report should meet the guidance set out within the CIEEM guidance ‘Biodiversity Net Gain Report and Audit Templates’ and include:

  • A statement outlining how the proposed development is intending to achieve Biodiversity Net Gain, include if biodiversity units will be delivered, on-site, off-site or through the purchase of units or statutory credits.
  • Be aware that Town and Country Planning Act 1990 (as amended) 37A (a) states that adverse effects should be avoided for habitats with a distinctiveness score of four or higher (this has been updated from previous considerations of six or higher).
  • How the Biodiversity Metric Principles and Good Practice Principles are being adhered to.
  • Consideration of whether the proposals for on-site habitat creation or enhancement are appropriate and feasible, taking into account how the site will be used.
    • Evidence such as soil sampling, should be included to support any delivery of habitats with a distinctiveness score of high or above.
  • The provision of sufficient information to support the allocation of habitat type and condition score for both baseline habitats and any proposed habitat enhancement or creation.
  • Baseline and proposed post-development plan.
  • Brief statement of how strategic significance has been applied.
  • Statement to support the document has been prepared by a professional ecologist with suitable qualifications and experience and be in accordance with the British Standard BS8683 ‘Process for designing and implementing biodiversity net gain: specification’.

2: Completed Statutory Metric

The Statutory Metric must be used. No other metric or earlier version will be accepted for new applications from the 12 February 2024.

All relevant sections of the metric must be fully completed prior to submission.

This includes the project details within the start page, and the user comments column to reference relevant information within the accompanying report or add further detail.

At this stage the metric can be considered a draft, however, it is anticipated that only minor changes will be required at the Biodiversity Gain Plan review stage.

By providing a full metric as part of the planning application it will reduce the risk at pre-commencement stage.

3: Mapping: GIS shape files

Files of both the baseline map and post-intervention (development proposals) map will need to be provided for on-site and any direct off-sites BNG delivery being proposed as part of the application.

The GIS files can be from any GIS system (QGIS, ArcGIS etc.), however, must be correctly georeferenced, and in a format that holds all relevant data and can be opened in ArcGIS software.

4: Habitat Management and Monitoring Plan (HMMP)

A HMMP (which can be considered draft at this stage) should be provided to demonstrate how any significant on-site enhancement will be monitored and managed.

5: Outline applications

Outline applications will only need to provide a Biodiversity Net Gain Report with a completed baseline assessment and accompanying GIS files.

Following planning permission

The documents and data you must supply following the granting of planning permission are:

Biodiversity Gain Plan

No work can commence prior to the approval of the biodiversity gain plan.

The Biodiversity Gain Plan should be:

  • submitted to planning, following planning permission being granted
  • completed and submitted alongside all the supporting information as referenced within the plan

The supporting documents and data, such as BNG report, Metric, Mapping and HMMP,  should be the final versions and reflect the information within the submitted Biodiversity Gain Plan.

The Biodiversity Gain Plan will be reviewed by BCC within 8 weeks of receiving the biodiversity gain plan.

Any significant enhancement in biodiversity on-site or any provision of biodiversity off-site will be registered on the net gain sites register following approval of the biodiversity gain plan.

It’s important that across all the documents provided within the application that the information is consistent and accurately presented.

These documents will be used to support the delivery and monitoring of biodiversity for a minimum of 30 years, therefore, they must meet the requirements set out within the table above.