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What is ‘biodiversity’?

Biodiversity, or biological diversity, is the variety and variability of all living things. It includes plants, animals, fungi, and microorganisms. It is a measure of variation across all biological scales, from the genetic to whole ecosystems – and everything in between.

Biodiversity is essential for our own health, wellbeing and survival. Biodiverse ecosystems enable food production, help to prevent flooding, regulate our climate and clean the air that we breathe. The more biodiverse an ecosystem is, the more resilient it is to current and future pressures.

Globally and in the UK, biodiversity is currently decreasing as a result of human activities. Habitat loss, climate change and pollution are some of the main drivers behind this decrease. Recognising the pressures that our natural environment is facing, the Council has declared climate and ecological emergencies. The protection and restoration of the natural world is a key priority of the Council’s Corporate Plan.

The Council has a legal duty to conserve and enhance biodiversity. This legal duty has to run in tandem with allowing sustainable development to occur. Sustainable development provides the homes and essential services that communities need.

Mandatory Biodiversity Net Gain (BNG)

BNG is an approach to development and land management that leaves biodiversity in a measurably better state than before, after first avoiding and minimising harm. The government has published a collection of BNG guidance here.

Mandatory BNG will require development proposals to deliver a 10% uplift in biodiversity value when compared to the vale of onsite habitats before development takes place. This uplift in value is calculated using the Statutory Biodiversity Metric.

Mandatory BNG will apply to different types of development at different stages:

  • From 12 February 2024 onwards, applications for planning permission of major development (unless exempt) will be subject to mandatory BNG.
  • From 2 April 2024, all other types of development (unless exempt) will be subject to mandatory BNG.

Please note: Planning applications submitted to the council after 16:30 on Friday 9 February 2024 will not be received until Monday 12 February 2024, due to council services being closed. This will mean that planning applications submitted after this time may be subject to mandatory BNG.

 Some key exemptions to BNG are:

  • Householder development
  • Proposals which have very small impacts (no impacts on priority habitat and <25m2 area habitat or <5m linear habitat) – known as the “de minimis” exemption
  • S73 applications, where the original permission was granted before the onset of BNG, or the change does not impact approved BNG
  • Self and custom build developments, subject to restrictions

A full list of exempted developments can be found here.

New validation requirements for BNG relevant applications

Where BNG applies, planning applications submitted to the council will not be validated unless all the following information or documents are provided:

  • A statement as to whether the applicant thinks that BNG applies to their proposal. If not, justification and evidence will need to be provided.
  • A statement confirming whether any habitats have been degraded onsite prior to the submission of the planning application.
  • A statement confirming whether any irreplaceable habitats are included within the red line boundary of the planning application.
  • A plan showing the type and extent of different habitats within the red line boundary, to scale.
  • The correct biodiversity metric, with the relevant baseline habitat sections completed.

Important BNG facts:

  • BNG relevant developments will be subject to the general biodiversity gain condition. This pre-commencement planning condition will require developers to submit a biodiversity gain plan to the council. This document needs to be approved in writing before any works can begin onsite.
  • The biodiversity gain plan details how the developer will achieve a 10% uplift in biodiversity value. The government have released a template for this document here.
  • The biodiversity gain plan cannot be submitted to the council, to discharge the general biodiversity gain condition, until at least one day after the grant of planning permission.
  • If 10% BNG cannot be achieved within the red line boundary of the planning application, offsite habitat creation can need to be relied upon. Offsite habitat creation can only be accepted where that habitat creation/enhancement has been secured with a legal agreement.
  • Offsite units can be purchased and allocated to a specific development, but those offsite gains must first be secured with a legal agreement and recorded on the statutory biodiversity gain site register.
  • Where a developer is unable to achieve 10% BNG onsite or offsite, statutory credits will be available to purchase as a last resort. These credits will be intentionally expensive to encourage the delivery of BNG onsite or close to the development site.

Biodiversity Net Gain: Good practice principles for development should be followed when designing developments and preparing planning applications.

BNG does not change existing protections afforded to biodiversity in the planning system.

Last updated: February 2024