The principle of biodiversity net gain (BNG) is to enhance biodiversity. It ensures habitats for wildlife are left in a measurably better state than they were before development took place. 

It is now mandatory for development to deliver a minimum of 10% biodiversity net gain. 

Developers are expected to follow the biodiversity hierarchy of Avoid, Mitigate, Compensate. BNG can be delivered onsite or offsite. If it is not possible to create the gains onsite the credits can be purchased offsite. If credits cannot be secured on the local market then statutory biodiversity credits must be purchased. 

BNG for major development

BNG became mandatory for major development on 12 February 2024.

Major development is any development which:

  • Provides 10 or more dwellings
  • Has a site area of over 0.5Ha or floorspace of 1000m2 
  • Includes any mineral and waste development 

BNG for minor development

For minor development:

  • BNG is mandatory from 2 April 2024.
  • Certain projects and development can be classed as exempt, including householder applications, existing applications and variation of conditions.  

View the full list of exempt applications

Information required to support a planning application

Exempt applications must include a supporting statement setting out which of the exemption criteria are met and evidencing that exemption. Photographs of the site or site plans with measurements may be required as supporting evidence.

Applications which are not exempt, will need to demonstrate that they have followed the biodiversity hierarchy and achieved the necessary minimum 10% gain by including the following documentation with their application:

  • A completed Biodiversity Metric (in Excel format)
  • A clear detailed plan of current on-site habitats
  • A supporting BNG report which describes the current biodiversity value on site and
  • A document setting out the principles of BNG on the site including:
    • Defining habitats to be retained, enhanced or created
    • Details of how the proposed habitats will be created
    • Details of how the habitats will achieve condition
    • How the habitats will be maintained for a minimum of 30 years

View the Statutory biodiversity metric tools and guides and associated guidance on GOV.UK

A standard condition will be applied to all relevant planning decisions under The Environment Act (2022) and is set out in Part 2, Regulation 13.

The condition states that development may not be started unless:

  • A biodiversity gain plan has been submitted to the planning authority, and
  • The planning authority has approved the plan

The council may choose to include additional conditions on the decision notice around securing elements of site design, landscaping etc. and will secure elements of BNG through a Section 106 agreement.

The biodiversity gain plan

The biodiversity gain plan is a document which sets out how a development will deliver biodiversity net gain and allows us, as the planning authority, to check whether the proposals meet the biodiversity gain objective.

View the standard template for a Biodiversity gain plan on GOV.UK.

Biodiversity credit banking

If you are a landowner and are considering using your land to create biodiversity credits to sell you will need to:

  • Engage with an experienced ecologist
  • Commission a baseline biodiversity assessment of the intended land using the most up to date metric 
  • Develop a proposal for the bank following advice from your ecologist who should be able to advise you which areas are most suitable for creating biodiversity uplift and what habitats can be created, taking into account soil type, historic land uses, elevations and drainage 
  • Establish a Habitat Management and Monitoring Plan covering a period of at least 30 years 

A habitat unit is a proxy measure for an area of land. Habitat units are used by the biodiversity metric tool when calculating biodiversity.

Any habitat units created must be secured for a minimum of 30.years by legal agreement. Currently a Section 106 agreement is the Council’s preferred mechanism.  

Any units created must be registered on the National Register.

Biodiversity net gain and the Local nature recovery strategy 

Local nature recovery strategies (LNRS) cover the whole of England. Each strategy area will include a local habitat map and a written statement of biodiversity priorities. A habitat unit is a proxy measure for an area of land. Habitat units are used by the biodiversity metric tool when calculating biodiversity.

If you deliver biodiversity units in a strategic area which has been identified in the LNRS, the biodiversity metric tool will attribute those units additional value.

The development of our LNRS is an ongoing process and locations of strategic significance within Herefordshire are currently being identified. 

Landowners and managers will have the opportunity to engage with the LNRS in spring and summer 2024. View further information on our Ecology pages.

Further information and contact details

If you are interested in the evolving LNRS, please let us know at