Biodiversity Net Gain

The Government has introduced a statutory requirement to deliver a 10% increase in biodiversity on major developments submitted on or after 12 February 2024 and for all other, non-exempt developments from 2 April 2024.

We are proposing to go further and we are exploring a 20% requirement through our emerging Local Plan (Plan 2040).

Further information about the requirement can be found in the Government’s Biodiversity Net Gain guidance and in their biodiversity net gain planning practice guidance.

Applications excluded from Biodiversity Net Gain

Some types of development are exempt. Further information on exempt developments can be viewed on GOV website. If you believe your development is exempt, you must include details on your planning application form. Evidence may be requested.

What you need to submit

The Government has set out minimum requirements for what must be provided. However, we may seek further information about the proposed strategy prior to making a decision on the planning application. We encourage early engagement with us through our planning pre-application advice service. The Government’s minimum requirements are as follows:

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

How Biodiversity Net Gain is calculated

Biodiversity net gain is measured in biodiversity units and must be calculated using the statutory biodiversity metric or the small sites metric, as appropriate.

One of the components used in calculating biodiversity units is strategic significance. The Local Nature Recovery Strategy covering Kent and Medway, once published, will be key to assigning strategic significance. Until then, an Interim Strategic Significance Guidance document has been produced, which should be used. For more information, visit the Biodiversity Net Gain for Kent and Medway webpage.

How you can deliver Biodiversity Net Gain

It can be delivered in the following ways, including in combination:

Where Biodiversity Net Gain should be delivered

On-site biodiversity net gain should be considered first, as set out in the biodiversity gain hierarchy, followed by registered off-site gains. Through our emerging Local Plan, we will be seeking to guide where off-site biodiversity net gain should be located.

If you are unable to provide biodiversity net gain on-site or on land you own, the Kent BNG Site Register provides details of land put forward as Biodiversity Gain Sites. This can be found on the Making Space for Nature in Kent and Medway website.

How Biodiversity Net Gain is secured

It can be secured either via a condition, a section 106 agreement or a conservation covenant.

Section 106 agreements may be required for significant on-site biodiversity net gain and will be required for off-site gains in some scenarios e.g. where not secured through a conservation covenant. This is likely to include a fee to cover our costs over the 30 years of monitoring and reporting on delivery of the section 106 agreement.

Where a section 106 agreement is likely to be needed, applicants should provide information at the earliest opportunity. 

Find out more about legal agreements to secure your biodiversity net gain.