Biodiversity Net Gain (BNG)

Biodiversity Net Gain (BNG) is a way of creating and improving natural habitats.

BNG makes sure development has a positive impact (net gain) on biodiversity.

In England, BNG is a statutory requirement under the Environment Act 2021. Developers must deliver at least a 10% increase in biodiversity. This means a development will result in more, or better quality, natural habitats.

Some developments are exempt from BNG. View BNG exemptions on the GOV.UK website.

You can find out more about BNG in:

Measuring biodiversity

BNG is measured in standardised units.

This is for all types of habitats, such as grassland, woods and lakes.

A habitat will contain different biodiversity units depending on things like its:  

  • size
  • quality
  • location
  • type.

Biodiversity units can be lost through development. Units can also be gained through development with work to create and improve habitats.

Find out more about calculating biodiversity with the statutory biodiversity metric on the GOV.UK website.

Submitting a planning application

If you’re submitting a planning application, you must provide certain information about BNG.

The government has set minimum requirements. We may also seek further information before deciding on a planning application. You should engage with us as early as possible through our pre-application advice service.

The government’s minimum requirements are:

  • a statement on whether you believe granted planning permission would be subject to biodiversity net gain
  • the pre-development biodiversity value of the habitat (on the date of application or an earlier date). This must show the calculations and calculation tool used, including publication date and version
  • where you wish to use an earlier date, the proposed earlier date and the reasons for proposing that date
  • a statement confirming whether the biodiversity value of the habitat is lower on the date of application (or an earlier date) because of activities. This must include supporting evidence if degradation has taken place
  • a description of any irreplaceable habitat on the land the application relates to (that exists on the date of application or an earlier date)
  • a plan for the existing habitat (on the date of application or an earlier date). This should be drawn to scale, show the direction of North and include any irreplaceable habitat.

Exemption under self-build and custom housebuilding

For self-build or custom housebuilding you need to complete our form.

This will help us understand if you meet the legal definition and are exempt from BNG.

Complete our self-build or custom housebuilding form

You must submit this form as part of your planning application.

Submitting a Biodiversity Gain Plan

Once planning permission has been granted, you may need to submit a Biodiversity Gain Plan. You can submit this through the Planning Portal as a discharge of conditions application. 

The governments minimum requirements are:

Within the plan you'll need to include:

  • the name and address of the person completing the plan, and if different the name of the person submitting the plan
  • a description of the development and the relevant planning reference number
  • pre-development plans showing the location of existing on-site habitats, and drawn to an identified scale and showing the North direction
  • the relevant date for calculating the pre-development biodiversity value of the development
    • if you're proposing an earlier date, the reasons for this
  • calculation of pre-development and post development biodiversity values, using the biodiversity metric calculation tools and stating the publication date of the metric used
  • arrangements for maintenance and monitoring of significant on-site habitat enhancements
  • a description of how the Biodiversity Gain Hierarchy will be followed and where one or more actions in the hierarchy are not followed, including the reasons, except for irreplaceable habitats
    • descriptions of any irreplaceable habitat on land relating to the plan on the relevant date
    • arrangement of compensation for any impact the development has on the biodiversity of the irreplaceable habitat
  • a statement if habitat degradation has taken place. If it has a statement, it will need to be provided, as well as:
    • the date immediately before the degradation activity
    • the completed biodiversity tool showing the calculation of the biodiversity value of the on-site habitat on the date
    • any available supporting evidence for the value.

More information

You can find more information on BNG on GOV.UK: