Biodiversity Net Gain

Closed 5 Feb 2024

Opened 8 Jan 2024


In 2021 The Environment Act was passed into UK law. This Act was introduced to stop the decline of species by 2030 and introduces a mandatory minimum Biodiversity Net Gain of 10% within any future development. This will ensure that such developments will improve or create new habitats for nature.

What is Biodiversity Net Gain (BNG)?

BNG is a strategy to stop any loss of nature. It is a way to allow the development of land but guarantee that it contributes to the recovery of nature in the process. It is a tool that will ensure habitats for wildlife are in better condition than they were before development, and allow biodiversity to flourish afterwards.

The benefits BNG will have for nature include protecting, enhancing and creating new local habitat networks. This will also have a positive impact for the wider community with improved open spaces and green networks and enhance air quality and flood resilience which will improve the boroughs overall resilience to climate change.

How will The Council Do this?

A BNG 'Supplementary Planning Document (SPG)' (see below) has been prepared to ensure the Council meets its requirements to implement BNG and provide clarity for all stakeholders explaining how this will be implemented within the borough. This will allow for a smoother transition when BNG becomes mandatory. 

Key points from the Biodiversity Net Gain (BNG) Supplementary Planning Document(SPD), (Attached below):

  • BNG will be mandatory for major developments from January 2024 and minor development from April 2024.
  • BNG requires a minimum 10% uplift in biodiversity from what was on the land before development.
  • BNG is required to be implemented and managed for a minimum of 30 years.
  • A biodiversity metric calculation must be submitted with planning applications. This calculates the baseline of biodiversity and converts biodiversity into units to calculate net gains. Details of the biodiversity metric can be found in section 3.2 of the BNG SPD.
  • There is a small sites biodiversity metric which is specifically for smaller sites, although there are some exemptions. Details of these can be found in section 3.4 of the BNG SPD.  
  • BNG is secured through legal agreements. Details can be found in section 3.11 of the BNG SPD.
  • It is expected that BNG will be delivered on-site in the first instance, then off-site and as a last resort through the governments statutory credit service which contributes to large scale, national biodiversity projects.
  • Biodiversity gain plans must be submitted and approved by the council before a development commences. Templates of these documents can be found in Appendix A of the BNG SPD.
  • It is a legal requirement to provide BNG and this will be monitored. Reports must be sent to the council. Details of monitoring can be found under section 3.12 and Appendix A of the BNG SPD.
  • The council can enforce against non-compliance of BNG.

Why your views matter

We are seeking your views on this important piece of legislation so that it may be incorporated into the new Castle Point Plan appropriately. Your input on the contents of the BNG SPD is an important part of the engagement process. 

A 'Strategic Environmental Assessment' (SEA) and a 'Habitats Regulations Assessment' (HRA) Screening Report on the BNG SPD have also been prepared (Attached below), and The Council are also seeking your comments on these documents. 

You can contribute by:

Completing our Online Survey and providing your views on this mandatory piece of legislation and how you feel about it's implementation and effect's for the future of the Castle Point Borough environment.

Please refer to the two Related documents below whilst completing the survey which should take about 5-10 minutes. Thank-you.



  • All Areas


  • Community groups
  • Young people
  • Working Aged People
  • Retired People
  • Older people
  • Women
  • Men
  • Major housebuilders
  • SME builders
  • Local agents
  • Statutory Consultees
  • Local Community Service Providers
  • Infrastructure Providers
  • Specialist Interest Groups


  • development management
  • Biodiversity