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

Habitat condition assessment: poor / moderate / good criteria

Habitat condition scoring uses Defra condition cards published alongside the JP039 metric; assessors must hold relevant CIEEM competency to sign off the survey for planning submission.

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

The three scores

Poor (1), moderate (2), good (3); the score multiplies through the metric alongside distinctiveness. Criteria are set per habitat class in the JP039 condition cards; for grassland the criteria include indicator species count, sward structure, absence of negative indicators, and management history.[S1]

The 2-band uplift cap rule

Post-development habitat condition cannot uplift more than 2 bands above baseline; a poor modified grassland cannot be scored as good lowland meadow on the post-dev side. The rule prevents over-claiming through aspirational condition scoring; it is enforced by the LPA at the metric submission stage.

Who can assess condition

CIEEM competency at full member (MCIEEM) or higher is the practical minimum; sole reliance on a junior surveyor risks condition disputes at planning consultation. CIEEM publishes a competency framework distinguishing PEA, condition, and species survey competencies.[S6]

Evidence pack at submission

A defensible evidence pack contains: dated photographs at each survey point; species lists per quadrat; sward height measurements; management history (where ascertainable); and a written condition rationale per polygon. The rationale is the document LPAs scrutinise most heavily.