Biodiversity Net Gain (BNG) Information

Last updated October 29, 2026.

On this page

1. When you'll need to provide this
2. What you'll need to include
3. Why we need it

When you'll need to provide this

You must include this if you're submitting your planning application to either Swale or Maidstone borough councils.

For applications submitted to either Swale or Maidstone borough councils

These requirements apply to applications sumittted to either Swale or Maidstone borough councils.

Threshold to be in-line with the current up-to-date Government advice where a Biodiversity Gain Plan would be required or where exemption is being argued.

Typical proposals

The biodiversity net gain (bng) information planning application requirement is typically needed when you're proposing to do any of the following:

What you'll need to provide

What you'll need to include in your application

For applications submitted to Maidstone Borough Council

Heathlands and Lidsing garden settlements must deliver 20% residential outside must demonstrate delivery of a minimum of 10% Biodiversity Net gain. All other development 10%.

For applications submitted to Swale Borough Council

Must demonstrate delivery of a minimum of 10% Biodiversity Net Gain.

• Statement of competency: for main metric this shall be produced by a suitably competent and qualified assessor (ideally a member of an appropriate recognised body).
• Small sites metric.

For proposals that include off-site or significant on-site BNG you should also provide your:

• Draft Habitat Management and Monitoring Plan (HMMP) template.

• Drawings of any off-site BNG proposals.

Where claiming an exemption:

Dated photos of the site from each boundary looking inwards.

For applications submitted to either Swale or Maidstone borough councils

Where a Biodiversity Gain Plan would be required:

• Kent & Medway Biodiversity Gain Statement

• Draft Biodiversity Gain Plan.

• Map showing baseline habitats on your development site.

• Map showing habitats after BNG has been implemented on the development site.
• Statutory biodiversity metric tools and guides including condition assessments. with pre and post development values completed (in Excel format).

Why we need you to provide this

Why we need you to include this in your application.

For applications submitted to Maidstone Borough Council

The Maidstone Local Plan Review has taken the 10% requirement further for the site allocations for Heathlands (LPRSP4 (A) and Lidsing LPRSP4 (B)  and require that such development deliver a minimum 20% biodiversity net gain, having regard to Biodiversity Opportunity and/or Nature recovery Networks. Biodiversity Net Gain should be calculated in accordance with the latest Natural England biodiversity metric or equivalent. (NB: the 2026 NPPF removed the requirement for 20% BNG for other residential development)

For applications submitted to either Swale or Maidstone borough councils

Biodiversity net gain is a way of creating and improving biodiversity by requiring development

to have a positive impact (‘net gain’) on biodiversity.

In England, biodiversity net gain is required under a statutory framework introduced by Schedule 7A of the Town and Country Planning Act 1990 (inserted by the Environment Act 2021). This statutory framework is referred to as ‘biodiversity net gain’ in Planning Practice Guidance to distinguish it from other or more general biodiversity gains.

Under the statutory framework for biodiversity net gain, subject to some exceptions grant of planning permission is deemed to have been granted subject to the condition that the biodiversity gain objective is met (“the biodiversity gain condition”). This objective is for development to deliver at least a 10% increase in biodiversity value relative to the pre- development biodiversity value of the onsite habitat. This increase can be achieved through onsite biodiversity gains, registered offsite biodiversity gains or statutory biodiversity credits.

In addition, to the minimum information requirements, it may be appropriate for local planning authorities to ask for further information in order to assist the consideration of biodiversity net gain as part of the determination of the planning application, where they believe this would be material to the consideration of the application. The amount of information on these matters will vary depending on the type and scale of development, type of planning application, the onsite habitat impacted, and the extent of any significant onsite enhancements.