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Biodiversity Net Gain (BNG)

Biodiversity Net Gain (BNG) is an approach to development that leaves biodiversity in a measurably better state after development than before, after first avoiding and minimising harm. BNG does not replace, but is in addition to, the existing policy and legal requirements related to biodiversity and development.

Under the Environment Act 2021, all developments except for some exemptions (such as Major Site applications made before 12 February 2024, Minor Site applications made before 2 April 2024, and householder applications) have to deliver at least 10% BNG.

From  6 August 2024, there are two new exemptions that will only apply if there are no impacts to priority habitats (e.g. priority hedgerows, rivers, grassland, woodland, orchards, ponds etc):

  •    Temporary Development for land which is to be reinstated within a period of 5 years or less, and
  •    Developments of 0.2 hectares or below  

All development applications made before 6 August 2026 (that are not exempt) must follow biodiversity gain hierarchy by first avoiding adverse impacts to habitat (particularly habitats of medium distinctiveness and higher), and where impacts are unavoidable, prioritising compensation in the following order where possible:​

  1. Enhancement of existing onsite habitats, ​
  2. Creation of new onsite habitats, ​
  3. Allocation of registered offsite gains, ​
  4. Last Resort: Purchasing Statutory Biodiversity Credits*

* Evidence that the developer has approached 3 local or national suppliers, habitat banks and that insufficient off-site options are available must first be provided, unless less than 0.25 Biodiversity Units are required.

Minor development applications (that are not exempt) made from 6 August 2026   can choose to go straight to allocating offsite gains, without prioritising onsite habitat creation/enhancement.

To measure BNG and assess the impacts of planning applications the Statutory Biodiversity Metric Tools and Guides must be used.

Further advice can be obtained from the council via our pre-application advice service.

Significant On-Site Gains

What counts as a significant enhancement varies depending on the scale of development and existing habitat, but these would normally be:

  • Habitats of medium or higher distinctiveness, 
  • Habitats of low distinctiveness which create a large number of biodiversity units relative to the biodiversity value of the site before development
  • Habitat creation or enhancement where distinctiveness is increased relative to the distinctiveness of the habitat before development 
  • Enhancements to habitat condition, for example from poor or moderate to good

The maintenance of significant enhancements must be secured with a S106 Agreement and 30-year Habitat Management and Monitoring Plan (HMMP) condition.

Private gardens, ornamental planting, and small areas of amenity grassland are unlikely to be considered ‘significant’. Local planning authorities are not obliged to secure the long-term management of these features for the purpose of mandatory BNG, but these areas (excluding private gardens) will likely still have long-term management secured through other mechanisms.

Strategic Significance

To determine the ‘Strategic Significance’ of habitat creation and enhancement, the Gloucestershire Local Nature Recovery Strategy (13th February 2026) must be used. 

If you have planning permission (including from before 12 November 2025) and still need to discharge the pre-commencement statutory planning condition for the submission of a Biodiversity Gain Plan, then you will need to update your biodiversity metric to refer to the published LNRS. Please speak to your project ecologist for further advice.

The table below explains how this affects the strategic significance of habitats within your development:

  Baseline Habitats Post-Development Habitats
Planning Applications validated before 13th February 2026 that have yet to discharge the Biodiversity Gain Condition The strategic significance of baseline habitats should not be amended.

High strategic significance must only be applied if proposed habitat creation or enhancement delivers one or more of the ‘Main Potential Measures’ within an ‘Area of Particular Importance for Biodiversity’ or an ‘Area that Could Become of Particular Importance for Biodiversity’.

 

This will result in a 15% increase in biodiversity units created.
Planning Applications validated on or after 13th February 2026 The strategic significance of all baseline habitat must always be scored as low.
  • Planning Application Form - containing statements on BNG such as whether the applicant believes that planning permission, if granted, would be subject to, or exempt from, the biodiversity gain condition and the reasons why; if any irreplaceable habitats are present; and whether any degradation to on-site habitats has occurred.
  • Baseline Habitat plan - drawn to an identified scale which must show the direction of North, showing on-site habitat existing on the date of application (or an earlier date), including any irreplaceable habitat.
  • Biodiversity Metric - showing the pre-development biodiversity value of the on-site habitats on the date of application (or an earlier date). Please ensure that ‘date of completion’, and ‘name of person completing the metric’ have been filled in, and that the Metric is saved as a macro-disabled excel file (.xlsx) with all sheets visible. Choice of biodiversity metric must be guided by the following the Statutory Biodiversity Metric User Guides.
  • Description of any irreplaceable habitat (as set out in column 1 of the Schedule to the Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations [2024]) present on the land to which the application relates, that exists on the date of application, (or an earlier date).

In addition to these minimum information requirements the following information is required for major development applications:

  • Post-Intervention Habitat Plan, drawn to an identified scale and including the direction of North, showing any habitats (UKHab) to be retained, enhanced, and/or created.
  • Off-Site Baseline and Post-Intervention Plans will be required if an off-site gain site is proposed. Plans must be drawn to an identified scale (including the direction of north), showing existing habitat to be retained and enhanced, and new habitats to be created.
  • A biodiversity net gain feasibility assessment - which can be included as a chapter in the Ecological Impact Assessment report or as a separate report. The assessment must include a rationale for the condition assessment and strategic significance assigned to each habitat type, and confirmation that the biodiversity gain hierarchy has been adhered.

If this information has not been provided, the Stroud District Council will refuse to validate the application.

 

In addition to any other information on the Biodiversity and Planning web page the following information should be submitted as soon after Validation as possible to allow a timely consideration before Determination: 

  • Draft Biodiversity Gain Plan (BGP) - using the Government’s BGP template.
  • Post-Development Habitat Plan - drawn to an identified scale and including the direction of North, showing any habitats (UKHab) to be retained, enhanced, and/or created.
  • A fully completed Biodiversity Metric calculation tool showing the baseline and post- intervention habitat.
  • Statutory Biodiversity Metric Condition Sheets – completed for each habitat parcel (if baseline condition is required by the metric).

Where off-site gains, or significant on-site gains are proposed:

 

 

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. The condition is deemed to apply to every planning permission granted for the development of land in England (unless exemptions or transitional provisions apply).

To discharge the biodiversity gain condition, the statutory framework requires a Biodiversity Gain Plan to be submitted to the Local Planning Authority prior to the commencement of development.

The Biodiversity Gain Plan must be submitted in writing, no earlier than the day after planning permission has been granted, and must contain a number of matters to enable the Local Planning Authority to determine whether the biodiversity gain objective has been met. This will require the developer to submit several documents as evidence alongside a completed Biodiversity Gain Plan

Submitting a compliance of condition application

  • Developers can apply to discharge the biodiversity gain at the same time as other planning conditions, however there will be a separate fee.

  • The Local Planning Authority will create a stand-alone compliance of condition application for the biodiversity gain condition (the suffix of the planning reference will be BGPCON).

  • The Local Planning Authority has 8 weeks to approve or refuse the application, and a separate decision notice will be issued.

  • The development cannot commence until the biodiversity gain condition has been discharged.

 

  • Final Biodiversity Gain Plan using the Government's Biodiversity Gain Plan template.
  • A completed copy of the Statutory Biodiversity Metric or Small Sites Metric (statutory biodiversity metric) excel spreadsheet in .xlsx format. 
  • On-Site Baseline Habitat Plan - drawn to an identified scale and showing the direction of North. It must include all baseline habitats, including the area of each habitat type. If the statutory biodiversity metric has been used, units must be in hectares for habitat areas and kilometres for linear habitats. If the small sites biodiversity metric has been used, units must be meters squared for the habitat areas and meters for linear habitats. The map must be submitted separately in pdf format. For significant onsite gains secured by S106 agreements – the map should also be submitted in GIS format (shapefile).
  • On-site post intervention map. The map must be drawn to an identified scale and show the direction of North. It must show existing habitat types to be retained and enhanced, and new habitat types to be created. If the statutory biodiversity metric has been used, units must be in hectares for habitat areas and kilometres for linear habitats. If the small sites biodiversity metric has been used, units must be meters squared for the habitat areas and meters for linear habitats.  The map must be submitted separately in pdf format. For significant onsite gains secured by S106 agreements – the map should also be submitted in GIS format (shapefile).

Developers may also need to submit the following information:

  • Off-site Baseline Habitat Plans and Post-Intervention Habitat Plans - if off-site gains are proposed on land within the developer’s ownership or through a third-party landowner. Plans must be drawn to an identified scale and show the direction of North. The maps must show existing habitat types to be retained and enhanced, and new habitat types to be created. If the statutory biodiversity metric has been used, units must be in hectares for habitat areas and kilometres for linear habitats. If the small sites biodiversity metric has been used, units must be meters squared for habitat areas and meters for linear habitats. The maps must be submitted in two different file formats: PDF and Shapefile.
  • A Habitat Management and Monitoring Plan (HMMP)* using Natural England’s HMMP template as a guide, detailing how significant on-site, and all off-site habitats will be established, managed and monitored.
  • Landscape and Ecological Management Plan (LEMP)* (or any other management condition linked to biodiversity net gain) if the Local Planning Authority has deemed this an appropriate alternative to a Habitat Management and Monitoring Plan (please refer to the conditions included on your decision notice).
  • If off-site units from an existing gains site are used, we will require confirmation that biodiversity units have been allocated to the development. If the allocation is not listed yet on the National Gains Site Register we will accept an email from Natural England confirming the allocation.
  • Proof of purchase of statutory biodiversity credits – if they have been used.
  • A compensation plan - if the development affects irreplaceable habitats.

*A HMMP and LEMP are long-term habitat management and monitoring strategies that detail a developer’s commitment to achieving the biodiversity gain objective. They are secured through separate conditions to the Biodiversity Gain condition, yet they are intrinsically linked. Therefore, the LPA are requesting developers apply for the approval of the Biodiversity Gain Plan and HMMP or LEMP conditions at the same time.

There are separate requirements for phased development. In this instance, the developer will need to complete and submit the following:

  • An Overall Biodiversity Gain Plan
  • A Phase Biodiversity Gain Plan (for each phase of the development) which can be submitted alongside reserved matters.

 

 

Where the creation or enhancement of significant on-site gains, or off-site gains are secured by S106 agreement – Stroud District Council charge the following monitoring fees:

30 Year Monitoring Fees (from 1 April 2026)

 

Technical difficulty:

 

 

Size:

Low

Moderate

High

Small (0 to 5ha)

£3,559

£4,245

£4,718

Medium (5+ to 20ha)

£5,495

£6,342

£7,705

Large (20+ to 40ha)

£9,731

£13,629

£20,564

To reflect the additional work and complexity, an additional 5% will be added where more than 7 habitat types are to be created (both area and linear based habitats).

All S106 agreements, including Deeds of Variation, are subject to a registration charge of £100. Payment of the £100 registration fee is required upon completion of the S106 agreement.

The monitoring fee will normally be due upon completion of the habitat creation/enhancement works. The chargeable amount will be subject to the financial index increases (BCIS All-in Tender Price Index) from the date of the agreement. For phased developments, fees may be apportioned across phases as specified in the agreement. 

Non-payment of monitoring fees will be treated as a breach of the S106 agreement, with the council able to pursue recovery through civil debt proceedings. The council will maintain detailed records of monitoring activities and costs to demonstrate compliance with Regulation 122(2A) requirements.

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