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 measurably positive impact (‘net gain’) on biodiversity, compared to what was there before development.

In England, BNG is 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 10%. This means a development will result in more or better quality natural habitat than there was before development. It supports the mitigation hierarchy of avoiding impacts first, then mitigating impacts and only utilising compensation as a last resort.

It does not change existing legal protections for important habitats and wildlife species.

Further guidance on the new BNG regime can be found here:

• GOV.UK guidance – Understanding biodiversity net gain

DEFRA biodiversity metric

The statutory (official) biodiversity metric is the means of measuring biodiversity value for the purposes of BNG. It measures all types of habitat, including:

• Grassland
• Hedgerows
• Lakes
• Woodland
• Watercourses such as rivers and streams

For BNG, biodiversity is measured in standardised biodiversity units which calculates:

• How many units a habitat contains before development takes place
• How many units are needed to replace the units of habitat lost and to achieve 10% BNG, through the creation or enhancement of habitat

The statutory (official) biodiversity metric calculation tool must be used in order to demonstrate that you have calculated the number of biodiversity units for existing habitat or habitat enhancements in accordance with the statutory biodiversity metric.

• GOV.UK guidance – Statutory biodiversity metric tools and guides

You may require an ecologist to produce the above documentation, as most major developments and some minor ones will require ecological input.

You can find an ecologist through The Chartered Institute of Ecology and Environmental Management (CIEEM) website.

BNG planning application requirements

From Monday 12 of February 2024 BNG is mandatory for all new major developments.

Major developments comprise:

• The provision of dwellinghouses where:
  1. The number of dwellinghouses to be provided is 10 or more
  2. The development is to be carried out on a site having an area of 0.5 hectares or more
• The provision of a building or buildings where the floor space to be created by the development is 1,000 square metres or more
• Development carried out on a site having an area of 1 hectare or more

BNG for other proposals will become mandatory on 2 April 2024.

There are specific exemptions to this requirement as follows:

De minimis exemption given that:

• That the development does not impact an onsite priority habitat
• That the development impacts:
  1. Less than 25 square metres of onsite habitat that has biodiversity value greater than zero
  2. Less than 5 metres in length of onsite linear habitat

Householder exemption

The biodiversity gain planning condition does not apply in relation to planning permission for development which is the subject of a householder application within the meaning of article 2(1) of the Town and Country Planning (Development Management Procedure) (England) Order 2015.

Self-build and custom build exemption

Self-build and custom build exemption for development which:

• Consists of no more than 9 dwellings
• Is carried out on a site which has an area no larger than 0.5 hectares
• Consists exclusively of dwellings which are self-build or custom housebuilding

Statutory submission requirement

All planning applications which are not exempt from BNG conditions will be required to submit:

• The completed Biodiversity Metric Tool showing the onsite habit score as of the date of the application or for an earlier proposed date with justification
• If any habitat degradation has occurred, the completed metric for before the degradation occurred
• The score in biodiversity units
• The publication date of the version of the metric being used (the current version’s publication date is 29 November 2023)
• If any degradation has occurred, a statement that it has occurred, when it started and any evidence for the date it started and the score before the degradation
• A description of any irreplaceable habitat* within the red line boundary as of the metric calculation date
• A scale plan (showing North) of the onsite habitat used in the calculations and any irreplaceable habitat

* irreplaceable habitat defined in The Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations 2024 Schedule 2.

EFDC local submission requirement

All applications (except those which are exempt) are recommended to provide full BNG details in the form of a draft biodiversity gain plan or biodiversity net gain statement. This should provide sufficient information to assess how the development has addressed the biodiversity mitigation hierarchy and how it is intending to meet the BNG objectives. This will also enable discussion as to whether any section 106 planning obligations are required to secure either significant onsite habitat enhancements or offsite gains for the development.

These requirements may be updated at a future date. Please check for any updates prior to submitting your planning application.

BNG does not alter existing requirements to provide ecological site survey information.

Post-determination and post-development

Once an application is approved, a condition is attached by statute to the planning permission requiring the submission of a biodiversity gain plan. This plan will describe how the 10% uplift in biodiversity will be achieved and must include the following information:

• Information about the steps taken or to be taken to minimise the adverse effect of the development on the biodiversity of the onsite habitat and any other habitat
• The pre-development biodiversity value of the onsite habitat
• Any registered offsite biodiversity gain allocated to the development before the date of submission of the biodiversity gain plan and the biodiversity value of that gain in relation to the development
• Any registered offsite biodiversity gain proposed to be allocated to the development and the biodiversity value of that gain in relation to the development
• Any biodiversity credits purchased before the date of submission of the biodiversity gain plan
• Any biodiversity credits proposed to be purchased for the development
• The post-development biodiversity value of the onsite habitat for the overall development

The biodiversity gain plan template can be found here:

• GOV.UK form – Biodiversity gain plan

A feature of the BNG regime is that BNG provision should be secured for a period of 30 years and managed and maintained appropriately. Natural England’s habitat management and monitoring plan template can be found here:

• Natural England – Habitat Management and Monitoring Plan Template (JP055)

How is EFDC supporting BNG implementation?

EFDC Adopted Local Plan 2023 (pdf 48MB)

Policy DM1 habitat protection and improving biodiversity

All development should seek to deliver net biodiversity gain in addition to protecting existing habitats and species. Development proposals should seek to integrate biodiversity through their design and layout, including, where appropriate, through the provision of connections between physical and functional networks.

Green Infrastructure Strategy (pdf 240KB)

Our Green Infrastructure Strategy sets out our strategic approach to existing and future green infrastructure assets in the district.

• Green Infrastructure Strategy

Local Nature Recovery Strategy (LNRS)

Our Local Nature Recovery Strategy (LNRS) is currently in development with Essex County Council:

• Essex Local Nature Partnership – Local Nature Recovery Strategy