What is Biodiversity Net Gain?

BNG became mandatory for major and minor applications under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021) as of 12th February and 2nd April 2024 respectively.
 
Essentially, this equates to all applications which include operational development (unless qualifying for specific exemptions – see below) need to deliver a minimum of 10% BNG as mandatory.

The developments listed below are the most common exemptions expected for applications within the borough:

• Existing planning applications (submitted before BNG was live);
• Variations of existing planning permissions;
• Developments below the ‘de minimis’ threshold which are those that:
  • Do not impact on priority habitats,
  • Impact on less than 25m² of on-site habitat which provides biodiversity value
  • Impact on less that 5m of on-site linear habitats. E.g. hedgerows
• Householder applications;
• Self-build and custom build applications;
• Biodiversity gain sites.

Further guidance on meeting biodiversity net gain requirements for developers is hosted on GOV.UK.

Further guidance on what types of development are exempt is hosted on GOV.UK.
 
It should be noted that the mandatory requirement for BNG is additional to existing requirements. Protections around designated nature conservation sites and important habitats and species are not superseded.

Biodiversity net gain will be measured using statutory biodiversity metric tools as identified by the Government. 
 
These tools calculate the biodiversity value (measured in biodiversity units) of habitats based on a number of factors including size, habitat type (distinctiveness), habitat quality (condition) and habitat location (strategic significance – further guidance below).
 
The metrics will look to compare the biodiversity units within a sites red line boundary before development against the value of the proposed development. The metric will guide on what losses are acceptable and where further creation and enhancement of habitats is required. Depending on the scale and complexity of the site there is also the option to use a Small Sites Metric which is a simplified version of the statutory metric tool that has been designed for use by non-ecologists to enable works on simple sites. Details surrounding when this simplified metric can be used will be found in the guidance linked below. 
 
Further guidance on the statutory biodiversity metric tools is hosted on GOV.UK.

Strategic Significance

Strategic Significance is a score that shows how important a location is for nature recovery. If a habitat is in a place that’s been identified as important for wildlife—such as areas shown in local nature recovery plans—it gets extra credit in the BNG calculation.

This helps steer new habitat creation and enhancement towards the places that need it most.
 
As the West Midlands Local Nature Recovery Strategy (LNRS) has now been published, applications within Dudley must calculate Strategic Significance using those provided resources in conjunction with published guidance on how to apply the multiplier within the biodiversity metric.

Developers need to adhere to the principles as set out within the Biodiversity Gain Hierarchy which is detailed in Biodiversity Net Gian Planning Practice Guidance. 
 
The hierarchy dictates that delivery of biodiversity net gain should be achieved in line with the following priority:

1. Through the enhancement of retained habitats and creation of new habitats within the sites red line boundary.
2. Where achieving net gain is not possible within the red line boundary, the remainder of the required biodiversity units can be achieved through offsite habitat enhancement which can be either on land owned by the developer or through buying biodiversity units from off-site habitat banks.
3. As a last resort, if biodiversity net gain cannot be achieved onsite or off-site then the developer must purchase statutory credits from the government.

It will be the Local Planning Authority's decision as to whether the Biodiversity Gain Hierarchy has been appropriately applied to each development. 
 
Successful planning applications (where not exempt) will be subject to a general biodiversity gain condition. This will require the submission of a Biodiversity Gain Plan for approval by the local authority, which will detail how the development will meet the requirement for 10% biodiversity net gain.

Further information and templates on Biodiversity Gain Plans are hosted on GOV.UK.
 
It is highly recommended that developers consider BNG as early as possible, including at site selection and initial layout design stage. Interaction with our pre-app service is highly recommended to help avoid delays or issues later at the point of determination. 
 
Details of our pre-app service can be found on our pre-app information page.

Significant on-site habitat and all off-site habitat gains will be required to be secured for at least 30 years via conditions, planning obligations or conservation covenants.

Significant on-site gain

Significant on-site gains would be areas of habitat enhancement which contribute significantly to the proposed development’s BNG, relative to the biodiversity value before development.
 
The definition of significant gains will depend on existing habitats on the development site and the scale of the proposal, and each case will be assessed individually. The definition of what is significant will be steadily explored as BNG applications are assessed across the professions and will change from site to site. In the meantime, please consult the guidance within the link below to help guide on what will and will not be considered significant on-site gains. 
 
Further guidance on significant on-site enhancements is hosted on GOV.UK.

Off-site gains

When off-site units are required, research should be completed to assess which offsite providers would be able to provide the sites specific BNG requirements.

There are a number of off-site biodiversity unit providers including:

• directly from a landowner
• from a habitat bank operator
• via a broker or through a trading platform

The council is working towards establishing its own habitat banks to provide off site provisions locally for use by local developments. When these resources are available further updates will be posted on this webpage. 

There are a number of statutory requirements for submission of planning applications that are subject to BNG assessment. Failure to meet these requirements will results in applications not passing validation stage. 
 
In addition to those statutory requirements the council requests additional information in order to fully assess how a planning application will achieve BNG in order to help ensure the feasibility of developments. 
 
Information regarding the statutory submission requirements as well as the additional information requested for validation of applications can be found on the Biodiversity Net Gain Validation Requirements guidance note.