Biodiversity net gain

Biodiversity net gain (BNG) is an approach to development that leaves biodiversity in a better state than before. Laws have been passed which mean BNG will become mandatory for new developments in England, leading to positive outcomes for nature.

1. Types of development it applies to

From 12 February 2024, BNG will be mandatory for new planning applications for major development made under the Town and Country Planning Act (TCPA) 1990, subject to specific exemptions set out in regulations referenced below.

Major development includes residential developments with 10 or more dwellings, or where the site area is greater than 0.5 hectares.

BNG for small sites will have an extended transition period and will apply from 2 April 2024. The definition of small sites is summarised below, with the full definition found in the regulations. Small site development includes:

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

BNG will apply to new applications for planning permission, except for applications for retrospective permission.

Applications made under any other route, for example deemed permissions under section 90 TCPA 1990 or permission granted by a Local Development Order, will not be subject to mandatory BNG.