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

30-year habitat management cost: per-hectare per-year liability

The 30-year management and monitoring liability is mandatory for any BNG delivery; typical net-present-value land is £1,500 to 4,500 per BU depending on habitat type.

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

Per-hectare per-year liability

Annual management cost varies sharply by habitat type. Species-rich grassland creation runs £200 to 600 per hectare per year; lowland mixed deciduous woodland creation £400 to 1,200 per ha per year; lowland fen restoration £700 to 2,000 per ha per year. Compound over 30 years and apply a 3.5% Defra discount rate to land the NPV.

Who holds the obligation

Three mechanisms exist: Section 106 agreement tying the obligation to the planning consent; conservation covenant held by a designated responsible body (the published list is small and slowly growing); or an integrated obligation held by the off-site supplier.[S7]

Monitoring cadence

Natural England guidance requires monitoring at years 1, 2, 5, 10, 15, 20, 25, and 30, with management plan reviews on the same schedule. The cost is a separate annual line; budget £500 to 1,200 per visit.[S5]

How it is bundled into off-site prices

Environment Bank, Nattergal, and similar operator-led habitat banks bundle the 30-year liability into the per-unit headline price; the buyer pays once and the operator carries the management and monitoring exposure. The bundling is the principal commercial reason off-site units are more expensive than the equivalent on-site delivery cost.