Woking Borough Council

Guidance on Biodiversity Net Gain

What is Biodiversity Net Gain?
Biodiversity Net Gain (BNG) is an approach to development, that leaves biodiversity in a measurably better state than before the development took place.
BNG is additional to existing habitat and species protections. Intended to reinforce the mitigation hierarchy, BNG aims to create new habitat as well as enhance existing habitats, ensuring the ecological connectivity they provide for wildlife is retained and improved
It uses the ecological mitigation hierarchy with a biodiversity metric to measure the impact of development on biodiversity.

 Figure 1: Shows Biodiversity Net Gain (Source: NE Brochure)

The Council’s net gain approach

The Environment Act gained ascension in November 2021 and has a two year transition period for its requirements to come into effect. The Act requires a mandatory Biodiversity Net Gain (BNG) of 10% on development for which Planning permission is granted under the Town and Country Planning Act 1990 (there are a few exemptions).

From the 12th February 2024 BNG will apply to major applications on:

  • residential development where the number of dwellings is more than 10, or if this is unknown, the site area is more than 0.5 hectares
  • commercial development where floor space created is more than 1,000 square metres or total site area is more than 1 hectare
  • any non-residential development of more than 1 hectare

From the 2nd April 2024 BNG will apply to minor development (small sites) on:

  • residential development where the number of dwellings is between 1 and 9, or if this is unknown, the site area is less than 0.5 hectares
  • commercial development where floor space created is less than 1,000 square metres or total site area is less than 1 hectare

The Council will expect developers to follow the biodiversity gain hierarchy and provide on-site BNG in the first instance.

Under the draft Planning Practice Guidance for BNG, the following must be submitted alongside applications for development subject to the general biodiversity gain condition:

  • 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 and earlier date), including any irreplaceable habitat.

Exemptions

The following types of development are exempt from BNG requirements:

  • Development affecting very small areas of habitat (<25m2 or 5m linear habitats);
  • Householder applications;
  • Small scale self/custom house builds;
  • Sites being enhanced for wildlife, such as BNG projects;
  • Developments affecting irreplaceable habitats; and
  • Permitted development.

Please note the following types of development are not exempt from BNG:

  • Developments on previously developed land (PDL) i.e., brownfield sites
  • Change of use
  • Temporary applications
  • Developments on statutory protected sites
  • Phased development -  please refer to the PPG BNG

For more information please refer to the Council's BNG Planning Advice Note here. This is considered a live document and may be updated in the future.

Further guidance: