Biodiversity net gain

What is Biodiversity Net Gain (BNG)?

BNG is a way of creating and improving natural habitats. BNG makes sure development has a positive impact (‘net gain’) on biodiversity. This is compared to what was there before the development took place.

This can happen by:

  • creating new habitats
  • or improving the habitats that are already there

Watch the video to find out what BNG is and how it can happen.

Why do I need to know about BNG?

In England, BNG is becoming mandatory under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021).

Developers must deliver a BNG of a minimum of 10%.

This means a development will result in more or better quality natural habitat than there was before development.

More information on how to deliver a BNG:

The diagram shows the difference between net loss, no net loss and net gain of biodiversity.

Green space that is developed and more green assets added equals biodiversity net gain

When is BNG happening?

  • BNG will be mandatory for new major development applications submitted on or after Monday 12 February 2024
  • BNG will become mandatory for small sites applications submitted on or after Tuesday 2 April 2024

Are any developments exempt of delivering BNG?

Some developments are exempt from BNG regulations and will not need to deliver BNG.

Find out what types of development are exempt

What information do I need to submit on BNG with a planning application?

  • statement as to whether the planning permission is subject to the BNG condition or not, and if not, what exemption is being applied
  • completed and dated Statutory Biodiversity Metric – please use the macro disabled version
  • the pre-development biodiversity value of the on-site habitat at the date of application (the metric will calculate this)
  • if an earlier date than the application date is used, please provide reasons for using that earlier date
  • statement confirming whether the biodiversity value of onsite habitat is lower on the application date due to any activity that has led to the degradation of habitats, with supporting evidence of that activity and degradation (if this is the case, the value will be taken as ‘pre-degradation)
  • description of any irreplaceable habitat (set out in column 1 of the Schedule of the Biodiversity Gain requirements (Irreplaceable Habitat) Regulations [2024]) on the application site that exists on the application date (or earlier where justified)
  • scale plan (with North arrow) showing existing onsite habitat as at the application date (or earlier where justified) including any irreplaceable habitat

Please note:

  • without all this information, we must refuse to validate the application
  • it is important to note that you will still need to submit specific tree and/or ecology information and reports in addition to the BNG documentation
  • applicants are encouraged to use our pre-application service should they have specific questions about BNG

How to measure biodiversity

For the purposes of BNG, the biodiversity value of a site is measured in standardised biodiversity units. A site will contain a number of biodiversity units, depending on things like:

  • size
  • quality of habitats
  • location
  • type of habitats

To measure the biodiversity value of a site you must use Statutory Biodiversity Metric, which calculates:

  • how many units a habitat contains before development
  • how many units are needed to replace the units of habitat lost or changed to achieve a minimum of 10% BNG

There is a Statutory Biodiversity Metric User Guide which explains how to complete the metric correctly.

How to achieve BNG

There are three ways to achieve the minimum 10% BNG:

  1. On-site by either enhancing or restoring within the red line boundary of the application site
  2. Off-site by enhancing or creating habitats on land outside of the application site
  3. Buy statutory biodiversity credits from the government (this should be used as a last resort)

A combination of all three can be used but BNG delivery must follow the biodiversity gain hierarchy.

If statutory credits are purchased, the government will use the funds to create habitat across England.

What else might I need to do to deliver BNG?

Once a planning application has been validated, the planning case officer will inform you what other information in needed from you.

This information may include:

  • a biodiversity gain plan
  • a habitat management and monitoring plan
  • legal agreements
  • details of BNG credits purchased

We might need these documents whilst the planning application is being decided or after the decision is made, but always before development starts.

More information for developers and applicants