Biodiversity Net Gain

The Environment Act 2021 requires that new developments must provide a minimum 10% net gain in biodiversity habitats secured for at least 30 years. 

This mandatory requirement applies to all major applications received from 12 February 2024 onwards and all small sites received from 2 April 2024. 

Biodiversity net gain is a mandatory condition on grant of planning permission. The condition will need to be discharged by submitting a specific Biodiversity Gain Plan application, which will need to be approved by the Planning Authority before commencement of the development.  

A specific legal agreement/Section 106 agreement will need to be signed in relation to biodiversity net gain. 

Further information is available here:

Understanding biodiversity net gain - GOV.UK (www.gov.uk)

Biodiversity net gain planning practice guidance - GOV.UK website

Major applications

Major planning applications will be expected to deliver a minimum of 10% biodiversity gains, with habitat management and monitoring secured for at least 30 years.

A major development requiring BNG is;

• erection of 10 or more dwellings or housing development on a site 0.5 hectare or more;
• erection of a builidng or buildings where the floor space to be created is 1,000m2 or more;
• development on a site 1 hectare or more
• minerals and waste development

Minor applications

Minor planning applications are expected to demonstrate no net loss, and appropriate net gain, using the latest DEFRA Small Sites metric (or agreed equivalent) - from April 2024.

Further information on qualifying criteria is due to be published by the government prior to this requirement applying.

Exemptions

Developments exempted from providing the 10% mandatory biodiversity net gain include: 

• Permitted development
• Urgent Crown development
• Development related to the high-speed rail transport network
• Development impacting habitat of an area below a 'de minimis' threshold of 25m² or 5m for linear habitats such as hedgerows, where no priority habitat is present
• Developments with a 0 baseline
• Householder applications
• Biodiversity gain sites (where habitats are being enhanced for wildlife)
• Small scale self-build and custom house building which:
  • consist of no more than 9 dwellings;
  • is an area no larger than 0.5ha;
  • consists of dwellings which are self-build or custom housebuilding.

Section 73 Applications & Permission in Principle

Section 73 permissions are exempt from the mandatory 10% net gain requirement where the original planning permission was either applied for, or granted, before 12 February 2024. 

Permission in Principle is not a grant of planning permission so the mandatory biodiversity gain requirement does not apply. However, the subsequent technical details consent (as a grant of planning permission) is subject to the 10% mandatory biodiversity gain condition.

National Validation Requirements

Information Applicants must provide with their planning application

This mandatory requirement applies to all major applications received from 12 February 2024 onwards and all small sites received from 2 April 2024. 

The Planning Portal's comprehensive online submission service, will be updated in line with the changes, and relevant application forms will be updated and available to download.

An application must be accompanied by the following minimum information to be validated:

• A statement as to whether the applicant believes that planning permission would be subject to the biodiversity gain condition;
• The pre-development biodiversity value of the onsite habitat on the date of application (or an earlier date) including the completed metric calculation;
• 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 value of the onsite habitat is lower on the date of application (or an earlier date) because of the carrying on of activities ('degradation'), as the value will be taken from before degradation;
• A description of any irreplaceable habitat (as set out in the Regulations) on the land to which the application relates;
• A Statutory Biodiversity Metric: Only excel format (xls) will be accepted,  shall include the date of the assessment and the assessor, and shall not include any red boxes unless the application is in outline, the applicant is requesting permission to purchase statutory biodiversity credits or Rule 4 of the metric has been instigated. Guidance can be found on the GOV.UK website;  and
• A plan showing onsite habitat existing on the date of application (or and earlier date), including any irreplaceable habitat.

Without this information your application will be invalidated and returned. The planning Portal has updated their forms to include the requirement to submit the above info fro relevant applications. 

Further information available -

Biodiversity net gain - Other permissions you may require - Planning Portal

Biodiversity net gain details required from 12 February 2024 | Planning Portal Blog