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 strategic significance: the LPA multiplier explained

Strategic significance lifts unit yield by 10% to 15% on parcels mapped as priority by the LPA via the Local Nature Recovery Strategy; the multiplier is a structural lever for siting decisions.

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

The multiplier values

Low (1.0), medium (1.1), high (1.15). The default for any parcel not mapped is medium; the LPA must publish or adopt a mapping for low and high to apply.[S1]

LNRS designation

Local Nature Recovery Strategies are statutory documents under the Environment Act 2021; each responsible authority publishes a mapping of priority areas for nature recovery. Parcels within mapped priority areas qualify for high strategic significance; parcels outside mapped areas remain at medium unless the LPA designates low.[S11]

What the multiplier means for off-site pricing

Off-site units within the same LPA at high strategic significance are worth more per ha than equivalent units outside the LPA; that pricing differential typically passes through to the buyer at £4,000 to 10,000 per BU.

Worked example by LPA

Cornwall publishes a comprehensive LNRS with high-significance coastal NCAs; on-site delivery in those NCAs benefits from the 1.15 multiplier. Surrey publishes selectively; Cambridgeshire’s LNRS prioritises chalk stream catchments. Always cross-reference the live LPA-published map; the calculator on this site defaults to medium where no mapping is known.[S12]