Information on irreplaceable habitats added to Biodiversity Net Gain

Defra has released new guidance for how Biodiversity Net Gain (BNG) will apply to irreplaceable habitats under the developer guidance section of their BNG page.

Irreplaceable habitats are those habitats which take significant time to restore, recreate or replace once they are destroyed, often as a result of their age, diversity or uniqueness. The definition and list of irreplaceable habitats for BNG are set out in the Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations 2024. This list includes:

  • Ancient woodland
  • Ancient and Veteran trees
  • Blanket bogs
  • Limestone pavements
  • Coastal sand dunes
  • Spartina saltmarsh swards
  • Mediterranean saltmarsh scrub
  • Lowland fens

When working with irreplaceable habitats developers should record all on-site irreplaceable habitats in the BNG metric calculation tool. However, because the biodiversity value of these habitats is so hard to recreate the 10% BNG requirement does not apply when irreplaceable habitats are lost. BNG does not change the existing protections and compensation requirements for irreplaceable habitats in planning policy. Planning permission for development resulting in the loss or deterioration of irreplaceable habitats will only be granted in exceptional circumstances.

Developers will need to:

  • Consider irreplaceable habitats at the design and planning application stage
  • Calculate BNG when there are irreplaceable habitats
  • Record irreplaceable habitats in the biodiversity gain plan

You can find more guidance from Defra on how irreplaceable habitats will work within BNG here.