Statutory Diligence GuideUpdated October 2026Follow on Google★

Free Biodiversity Net Gain Calculator Online UK: 10% BNG Estimator

Statutory Source: Environment Act 2021 & Defra Statutory Biodiversity Metric 4.0

Quick Answer: Free Biodiversity Net Gain Calculator Online UK: 10% BNG Estimator

Our free online Biodiversity Net Gain Calculator allows property developers, architects, planning consultants, and self-builders to model statutory 10% BNG requirements in seconds. Input your development site area, select your existing baseline habitat types (arable, grassland, scrub, hardstanding), configure proposed on-site green infrastructure (gardens, bioswales, green roofs), and calculate your exact net gain or shortfall percentage. If a deficit occurs, the calculator automatically estimates required off-site units and statutory credit costs.

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How to Use the Interactive BNG Calculator

Our interactive tool models statutory algorithms under the Environment Act 2021:

Step 1: Enter your total site area in hectares (e.g. 0.75 ha).

Step 2: Assign baseline percentages to existing site habitats (e.g. 70% modified grassland, 30% hardstanding).

Step 3: Model proposed on-site enhancements (retained trees, biodiverse rain gardens, native hedgerows).

Step 4: Review your projected net gain score. If below 110%, the tool models required off-site units and estimated credit acquisition costs.

Step 5: Download your official certified 1-page A4 statutory planning diligence brief with SHA-256 verification.

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Instant 3-Second Statutory Screening

Check Any Property Across 12 Official Statutory Registers

Conducting property due diligence requires cross-referencing multiple public registries. Run a free instant desktop screening across Environment Agency flood models, British Geological Survey subsidence data, UKHSA radon maps, HM Land Registry sold prices, and local planning constraints.

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Environment Agency FloodingSurface water, rivers & sea risk bands

BGS Ground StabilityShrink-swell clay & subsidence risk

UKHSA Radon Gas PotentialOfficial radon class & protection rules

HM Land Registry PricesHistorical transactions & tenure type

EPC Energy & RdSAP SpecsOfficial construction era & wall fabric

Planning Applications BufferRecent nearby planning notices (500m)

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Official Primary Verification Registers

Cross-reference property diligence across verified UK government open registers under the Open Government Licence v3.0:

Category: Biodiversity Net Gain & Planning Law

Property Age & RdSAP Era

Official construction age bands, wall specifications, and earliest conveyance dates.

MHCLG Energy ActOpen Tool

Council Tax & Precepts

Statutory Band A–H ratios, police/fire levies, and 1 April 1991 baseline thresholds.

Local Govt Finance Act 1992Open Tool

Public Rights of Way (PRoW)

Conclusive legal proof of footpaths, bridleways, and restricted byways on land.

Wildlife & Countryside Act 1981Open Tool

Planning & Consultations

Live planning applications, 21-day neighbor notices, and permitted development appeals.

Town & Country Planning Act 1990Open Tool

Flood Risk & Surface Water

Statutory Flood Zones 1, 2, 3, 30/100/1000-year pluvial models, and Flood Re rules.

Flood & Water Mgt Act 2010Open Tool

Land Registry Sold Prices

Verified historical completion prices, title deed values, and regional ONS house price indices.

Land Registration Act 2002Open Tool

Stamp Duty (SDLT)

Exact progressive residential thresholds, £300k FTB relief, and 5% additional home surcharges.

Finance Act Statutory ScheduleOpen Tool

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Topical Knowledge Cluster

Inspect Any UK Property on Our Biodiversity Net Gain Calculator (BNG)

Run an instant preliminary screening across official government databases including the MHCLG EPC register, HM Land Registry, and Environment Agency records.

Launch Biodiversity Net Gain Calculator (BNG)

Official Statutory Notice & Guidance:

This guide is compiled for informational due diligence referencing official statutory records from Environment Act 2021 & Defra Statutory Biodiversity Metric 4.0 under the Open Government Licence v3.0. Legal titles and physical structural condition should always be independently inspected by a qualified conveyancing solicitor and chartered RICS surveyor prior to legally binding property commitments.