Biodiversity Net Gain (BNG)

What is Biodiversity Net Gain (BNG)?

Biodiversity is the variety of all living things on our planet, including species, habitats and ecosystems.

Biodiversity net gain (BNG) is a way of creating and improving the natural environment by ensuring development has a measurably positive impact (‘net gain’) on biodiversity, compared to what was there before development.

In England, BNG became mandatory for major developments from 12 February 2024 and for minor developments from 2 April 2024 under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021). Developers must demonstrate through a planning application that the development proposal will deliver a BNG of at least 10%. This means a development will result in more or better quality natural habitat than there was before the development.

Detailed guidance and information on BNG can be found in the Government’s Planning Practice Guidance and DEFRA's website: Information you need for BNG.

Exemptions

There are some specific exemptions from biodiversity net gain for certain types of development, including:

Householder development applications;

Permitted development or development granted through a development order;

Development subject to the de minimis exemption i.e. does not impact priority habitat, impacts less than 25 square metres of onsite habitat, or 5 metres of linear habitats such as hedgerows;

Self-build and custom build development;

Urgent Crown development;

Development of a biodiversity gain site;

High speed railway transport network (HS2) related development.

Full details of the exemptions are set out in paragraph 17 of Schedule 7A of the Town and Country Planning Act 1990 and the Biodiversity Gain Requirements (Exemptions) Regulations 2024.

How is BNG measured?

A biodiversity metric is used to measure the biodiversity value of habitats in standardised biodiversity units for the purpose of BNG. The statutory (official) biodiversity metric calculation tool must be used to demonstrate the number of biodiversity units for existing habitat or habitat enhancements to meet mandatory BNG requirements.

The statutory biodiversity metric measures all types of habitat, including grassland, hedgerows, lakes, woodland and watercourses such as rivers and streams. The metric calculates different types of biodiversity units across three modules including area habitat units, hedgerow units and watercourse units, which are used to calculate:

how many biodiversity units a habitat contains before development takes place; and

how many biodiversity units are needed to replace the units of habitat lost to achieve 10% BNG, through the creation or enhancement of habitat.

The statutory metric must be completed by a competent person such as a professional ecologist, who will be able to enter the correct information and provide advice on the metric tool’s calculations. The Chartered Institute of Ecology and Environmental Management publishes guidance on how to find a suitable consultant.

Small site developments can use the statutory metric tool or if preferred can use a simpler version of the metric tool, called the small sites metric (SSM). The Planning Practice Guidance includes further information on the small sites metric and a detailed user guide.

Full guidance on using the statutory biodiversity metric is available within the Government’s Planning Practice Guidance: Calculate biodiversity value with the statutory biodiversity metric.

BNG requirements for planning applications

Qualifying developments must demonstrate through a planning application that they will deliver 10% net gains for biodiversity, which must be secured, managed, and monitored for 30 years.

Applicants are encouraged to engage with the Council before submitting your planning application through our pre-application advice procedure, particularly if you are unclear of what information should be submitted as part of your proposal. This will help to improve both the efficiency and effectiveness of the planning application process, reduce issues around validation, and improve the quality of the application.

It should be noted that Melton Borough Council does not have an in-house ecology team, but is reliant on Leicestershire County Council as a statutory consultation body for all ecology advice and expertise through the planning application process. The County Council no longer offer pre-application advice directly to applicants; however, Melton Borough Council planning officers will be able to guide you through the process as part of your application.

Where qualifying developments are subject to BNG, the planning application must be accompanied by minimum information set out in Article 7 of The Town and Country Planning (Development Management Procedure) (England) Order 2015, including:

a statement as to whether the applicant believes that planning permission, if granted, would be subject to the biodiversity gain condition;

the pre-development biodiversity value of the onsite habitat on the date of application (or an earlier date) including the completed metric calculation tool used showing the calculations, the publication date and version of the biodiversity metric used to calculate that value;

where the applicant wishes 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 onsite habitat is lower on the date of application (or an earlier date) because of the carrying on of activities (‘degradation’) in which case the value is to be taken as immediately before the carrying on of the activities, and if degradation has taken place supporting evidence of this;

a description of any irreplaceable habitat (as set out in column 1 of the Schedule to the Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations [2024]) on the land to which the application relates, that exists on the date of application, (or an earlier date); and

a plan, drawn to an identified scale which must show the direction of North, showing onsite habitat existing on the date of application (or an earlier date), including any irreplaceable habitat.

If this information has not been provided, the Council will decline to validate the application as it will not meet the nationally set validation requirements for planning applications. Leicestershire County Council are developing guidance which may include further local additional requirements at validation stage.

Within the planning application form applicants will be asked to confirm whether this information accompanies the application. Where these details have been provided elsewhere in accompanying documents, applicants can refer to these rather than duplicate this information within the application form.

Important note: The requirement for biodiversity net gain doesn’t alter existing requirements and protections for the natural environment such as protecting important habitats and species, which must be achieved alongside providing 10% BNG.

Delivering BNG on-site and off-site

All planning applications subject to BNG requirements should consider BNG from the outset, prior to site design, and ideally at site selection stage to help minimise the need for providing replacement habitats. Early consideration can help to achieve good placemaking and reduce any unnecessary delays or potential additional costs later in the planning process in meeting BNG requirements.

BNG can be achieved on-site, off-site or through a combination of on-site and off-site measures, or through the purchase of statutory biodiversity credits.

On-site biodiversity gains are the preferred solution, where gains are achieved within the development site and can be linked to the provision of green spaces, such as gardens, community orchards and landscaped areas.

There will be some circumstances when the full BNG requirement cannot be met on-site within the application site boundary, which will result in off-site BNG habitat being required. Off-site biodiversity gains can be provided on an alternative site, either within the same land ownership as the proposed development site, or through the purchase of off-site biodiversity units on the market, such as through a registered habitat bank provider.

If it is not possible to deliver BNG on-site or off-site, then statutory biodiversity credits can be purchased from the Government, but these should be used as a last resort and have purposefully been priced to be unattractive to developers.

Wherever possible applicants must prioritise in order the enhancement of existing on-site habitats, creation of new on-site habitats, allocation of registered off-site gains and finally the purchase of biodiversity credits. Developments can combine these options, but must follow this order of priority, which is referred to as the ‘Biodiversity Gain Hierarchy’ within the Planning Practice Guidance.

Habitat Banks

Habitat banks are areas of land where habitats have been created or enhanced to provide an uplift of biodiversity units, which can qualify as registered off-site biodiversity gains and be sold to developers to meet their BNG requirements. A legal agreement with the local planning authority or conservation covenant with a responsible body must be in place detailing the habitat enhancement and maintenance for at least 30 years prior to registering the habitat bank.

Melton Borough Council is not currently aware of any registered habitat banks within the borough. The Council is keen to progress with the registration of habitat banks and recognises the importance of retaining off-site biodiversity gains within the borough, particularly where this can help to meet strategic nature recovery priorities within the area; however, it is not a statutory requirement for local planning authorities to enter into a legal (section 106) agreement to secure habitat banks and statutory BNG responsibilities are currently the priority. Processes to achieve this are being explored with Leicestershire County Council’s ecology team.

Defra has highlighted online platforms such as Gaia or Future Homes Hub to understand the market for biodiversity units in greater detail as these provide a visual database of available units through registered biodiversity gain sites. Natural England is also developing a publicly available site register that will include information about any site being used to deliver BNG.

If you own land within Melton borough that you consider would be appropriate to register as a habitat bank, please submit details of this and any supporting information by email to: planningpolicy@melton.gov.uk and we will contact you with further information when this is available.