BNG Calculatorv4.0 / JP039
Statutory Biodiversity Metric v4.0 (JP039)· Defra GOV.UK guidance, last updated 2 June 2026· NSIP extension live 2 November 2026· Reviewed 21 June 2026

BNG by Local Planning Authority: local policy variations

Most LPAs apply the statutory 10% minimum; a growing minority have adopted higher local requirements through their Local Plan or Biodiversity SPD.

Awaiting MCIEEM peer review · CIEEM (Chartered Institute of Ecology and Environmental Management)

LPAs requiring more than 10%

The PAS BNG resource tracks the live position.[S12]

Biodiversity Supplementary Planning Documents

Several LPAs have adopted standalone Biodiversity SPDs that codify their local policy, mapping, and validation expectations; submitting against the SPD is the safest path. Where no SPD exists, the Local Plan biodiversity policy applies.

LNRS alignment

LPAs that have published their LNRS provide cleaner strategic significance mapping; LPAs that have not still apply the medium default. The LNRS rollout is uneven; check the local LPA before assuming high significance.[S11]

Where exposure is highest

The greatest exposure is in LPAs requiring more than 10% and with mapped high strategic significance; a 20% requirement at 1.15 strategic compounds to a 38% effective uplift on baseline. Cost rises proportionally.