Biodiversity Net Gain

The Government has introduced the requirement for Biodiversity Net Gain (BNG) under a statutory framework introduced by Schedule 7A of the Town and Country Planning Act 1990 (inserted into the 1990 Act by Schedule 14 of the Environment Act 2021).

Under the statutory framework for biodiversity net gain, every grant of planning permission (with some exceptions) is deemed to have been granted subject to a general biodiversity gain condition to secure the biodiversity gain objective.  This objective is to deliver at least a 10% increase in relation to the pre-development biodiversity value of the development granted permission.  This increase can be achieved through onsite biodiversity gains, registered offsite biodiversity gains or statutory biodiversity credits.

The biodiversity gain condition is a pre-commencement condition: once planning permission has been granted, a Biodiversity Gain Plan must be submitted and approved by the planning authority before commencement of the development.

There are also relevant exemptions and transitional arrangements. 

There is a national set of validation requirements for applications where Biodiversity Net Gain applies.  These are as follows (taken from the Planning Practice Guidance):

Where an applicant believes the development would be subject to the biodiversity gain condition, 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:

• confirmation that the applicant believes that planning permission, if granted, would be subject to the biodiversity gain condition;
• the pre-development biodiversity value(s), either on the date of application or earlier proposed date (as appropriate);
• where the applicant proposes to use an earlier date, this proposed earlier date and the reasons for proposing that date;
• the completed metric calculation tool showing the calculations of the pre-development biodiversity value of the onsite habitat on the date of application (or proposed earlier date) including the publication date of the biodiversity metric used to calculate that value;
• a statement whether activities have been carried out prior to  the date of application (or earlier proposed date), that result in loss of onsite biodiversity value (‘degradation’), and where they have:
  - a statement to the effect that these activities have been carried out;
  - the date immediately before these activities were carried out;
  - the pre-development biodiversity value of the onsite habitat on this date;
  - the completed metric calculation tool showing the calculations, and
  - any available 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
• plan(s), drawn to an identified scale and showing the direction of North, showing onsite habitat existing on the date of application (or earlier proposed date), including any irreplaceable habitat (if applicable).

If this information has not been provided, the local planning authority will likely refuse to validate the application. Within the planning application form applicants will be asked to confirm whether this information accompanies the application. Where these details have been provided elsewhere in accompanying documents, applicants are encouraged to cross-reference to these rather than duplicate this information within the application form.

Applicants should be aware that local planning authorities may request further information relating to biodiversity net gain as part of the planning application.

These requirements are intended to allow consideration of existing habitat baselines for relevant applications so there is an understanding about the pre-development biodiversity value of the development’s onsite habitat at this stage.

The Government has also confirmed that Local planning authorities may also seek further information, where it is appropriate to do so, about the proposed approach to meeting the biodiversity gain objective for the development.

The relevant application forms have been updated to include questions relating to Biodiversity Net Gain.
 

Hertfordshire Ecology have provided further guidance including details of the level of information that should be provided to support applications that include a requirement for BNG (Advice for Ecological Professionals).  If reports are submitted that do not meet these standards, it is likely that Hertfordshire Ecology will advise the local planning authority that the report cannot be relied on.  This is likely to result in increased delays and all ecological assessments must reference and follow best practice guidance.  This guidance is also likely to be frequently updated.

https://www.hertfordshire.gov.uk/services/recycling-waste-and-environment/bio-diversity-wildlife/ecology-advisory-service.aspx#

The Planning Practice Guidance sets out the following exemptions:

While every grant of planning permission in England is deemed to have been granted subject to the biodiversity gain condition, commencement and transitional arrangements, as well as exemptions, mean that certain permissions are not subject to biodiversity net gain.

Biodiversity net gain has only been commenced for planning permissions granted in respect to an application made on or after 12 February 2024. Permissions granted for applications made before this date are not subject to biodiversity net gain.
   
Biodiversity net gain 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

Biodiversity net gain has not been commenced yet for planning permissions which have been granted through other routes to permissions. These include:

• Local development orders;
   
• Simplified Planning Zones;
   
• Neighbourhood development orders;
   
• Successful enforcement appeals; and
   
• Deemed planning permission.

The grant of permission in principle is not within the scope of biodiversity net gain (as it is not a grant of planning permission), but the subsequent technical details consent (as a grant of planning permission) would be subject to the biodiversity gain condition.
  
The approval of reserved matters for outline planning permissions is not subject to the biodiversity gain condition (as it is not a grant of planning permission).

There are specific exemptions from biodiversity net gain for certain types of development. The exemptions are set out in paragraph 17 of Schedule 7A of the Town and Country Planning Act 1990 and the Biodiversity Gain Requirements (Exemptions) Regulations 2024.

The biodiversity gain condition does not apply to the following types of development:
 

• Householder development. Development which is subject of a householder application as defined within Article 2(1) of the Town and Country Planning (Development Management Procedure) (England) Order 2015.
• Development granted planning permission by a development order under section 59. This includes permitted development rights.
• Development subject to the de minimis exemption. Development that does not impact a priority habitat and impacts less than 25 square metres (e.g. 5m by 5m) of onsite habitat, or 5 metres of linear habitats such as hedgerows.
• Self-build and custom build development. Development which:
  - consists of no more than 9 dwellings, and
  - is carried out on a site which has an area no larger than 0.5 hectares, and
  - consists exclusively of dwellings which are self-build or custom housebuilding as defined in section 1(A1) of the Self-build and Custom Housebuilding Act 2015.
• Urgent Crown development granted permission under section 293A of the Town and Country Planning Act 1990.
• Development of a biodiversity gain site. Development which is undertaken solely or mainly for the purpose of fulfilling, in whole or in part, the biodiversity gain condition which applies in relation to another development.
• Development related to the high speed railway transport network. Development forming part of, or ancillary to, the high speed railway transport network comprising connections between all or any of the places or parts of the transportnetwork specified in section 1(2) of the High Speed Rail (Preparation) Act 2013