Everything UK developers, architects and planners need to understand and comply with the mandatory 10% Biodiversity Net Gain requirement under the Environment Act 2021.
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BNG is a way of making sure development leaves the natural environment in a measurably better state than before. Under the Environment Act 2021, most developments in England must deliver at least a 10% increase in biodiversity value, measured with the Statutory Biodiversity Metric and secured for 30 years.
Most planning applications in England. Major developments have required BNG since 12 February 2024 and small sites (under 10 dwellings or 0.5 ha) since 2 April 2024. NSIPs come into scope from late 2025. Householder applications and certain de minimis sites are exempt.
Using the Statutory Biodiversity Metric: biodiversity units = area × distinctiveness × condition × strategic significance, adjusted for spatial and temporal risk. A baseline is measured, the post-development scenario is calculated, and the difference must be at least +10%.
A Habitat Management and Monitoring Plan (JP058) sets out how created and enhanced habitats will be managed and monitored over the 30-year period. LPAs increasingly require it before discharging the biodiversity gain condition.
A traditional ecological consultancy typically charges £2,000–£8,000 and takes 5–10 working days. A BioNetGain Pro submission pack starts at £295 and is delivered in under one hour.
Usually yes — for the Preliminary Ecological Appraisal (PEA), which covers protected species and designated sites. That's a separate requirement from BNG. Your ecologist handles the PEA; BioNetGain Pro handles the BNG compliance layer.
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