Biodiversity Net Gain

The final biodiversity net gain (BNG) regulations have been laid before parliament and, following the usual parliamentary process, BNG became mandatory for new major developments (unless exempt) on Monday 12th of February 2024 and all minor developments (unless exempt) from 2nd April 2024..  All new developments now have to deliver net gains for biodiversity leading to positive outcomes for nature, better places for local communities and more consistent and transparent requirements for developers.

Which types of development will BNG apply to?

BNG will apply to new applications for planning permission, except for applications for retrospective permission. Further exemptions can be found on the following Government websiteBNG Exempt Developments (opens new window)

Where you consider a development is exempt then your application must be accompanied by a statement setting out why you think your development is exempt, quoting the relevant parts of the Regulations

Applications made under any other route, for example deemed permissions under section 90 TCPA 1990 or permission granted by a Local Development Order, will not be subject to mandatory BNG yet. Further regulations will be required to modify the procedure for these other routes to planning permission. Details regarding these further regulations are expected to be released in due course.

Transitional Arrangements

BNG will only apply where the planning application was made on or after the 12th of February 2024 for major applications, or the 2nd of April 2024 for minor applications.

'Made' means the application must have been valid before the 12th of February 2024 for major applications and before the 2nd of April 2024 for minor applications.  Failure to submit a valid application before these dates will mean additional validation requirements, including the BNG statement and metric and at least 10% BNG to be delivered, as per the regulations.

Calculate biodiversity value with the statutory biodiversity metric (opens new window)

These transitional arrangements also mean that if you received planning permission before the 12th of February, and that permission wasn't subject to BNG, if you then apply via section 73 to vary a planning condition on that permission, the new permission granted under section 73 would also be exempt from BNG.

If a planning application for a small site development was made during the small sites extended transition period, between the 12th of February and the 2nd of April 2024, and subsequently a section 73 variation was granted after the 2nd of April, the same transitional arrangements will apply and BNG will not be required on any subsequent section 73 variations.

Advice to applicants and agents

There is a lot of advice available on the GOV.UK website and aBiodiversity Net Gain step by step guide for developers (opens new window) 

Please note the Council are unable to assist with queries about BNG or completing the metric, you will need to engage with a suitably qualified ecologist, as set out in the Regulations. 


Further information can be found in the following regulations:

The Biodiversity Gain (Town and Country Planning) (Modifications and Amendments) (England) Regulations 2024 (opens new window)

The Biodiversity Gain Requirements (Exemptions) Regulations 2024 (opens new window)

The Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations 2024 (opens new window)

The Biodiversity Gain Site Register Regulations 2024 (opens new window)

Last updated: 10/04/2024 10:14:36