Three inputs (hectares, dominant habitat, distinctiveness) return the biodiversity units needed for the 10% net-gain obligation, the statutory credit cost from the GOV.UK price list, and the off-site cost at a quote you enter. No signup.
Auto-resolved from the JP039 habitat lookup; editable to model alternative classifications. [S1]
Assumes moderate condition, medium strategic significance, and no habitat retained on site, so the units are a ceiling. Hedgerow and watercourse units use separate modules and are not modelled here.
Not priced here: the cost is your own habitat creation works plus 30 years of management and monitoring, which depend on the habitat management and monitoring plan for the site.
See the 30-year management page. [S1]
No public rate card exists: operators such as Environment Bank quote per project, and Defra says statutory credit prices are not guideline prices for off-site units. [S3]
This is a feasibility calculator: it reproduces the JP039 v4.0 core arithmetic in plain TypeScript. It does NOT replace the bound Defra spreadsheet at planning submission; appoint a CIEEM-registered ecologist for the formal output.
A BNG calculator sizes the biodiversity unit delta a development must deliver to satisfy the statutory 10% net-gain requirement under the Environment Act 2021. The Statutory Biodiversity Metric v4.0 (JP039) multiplies distinctiveness, condition, area, and strategic significance to produce baseline biodiversity units. Required delta = baseline x 1.10 minus post-development units. The delta can be met on site, with off-site units, or with statutory credits as the last resort. [S1]
Most SERP competitors return a single GBP estimate. The buyer’s actual decision is a routing problem; can the delta be delivered on the development parcel, bought as registered off-site units in the same Local Planning Authority, or forced to statutory credits as the punitive backstop. This calculator surfaces all three from the same input set so the viability appraisal can compare them like-for-like.[S2]
Statutory credits carry a spatial risk multiplier that doubles the credits needed: 2 credits per biodiversity unit, so a Tier A1 credit at £42,000 means £84,000 per unit.[S3] Off-site units have no public rate card. Defra states that statutory credit prices are not guideline prices for off-site units, and habitat bank operators such as Environment Bank quote per project, so the calculator prices off-site units at the quote you enter.[S3]