Biodiversity Net Gain (BNG) in London
Planning-ready BNG assessments for London — clear metrics, proportionate uplift strategies and predictable progress through planning.
BNG Requirements in London
Most developments in London now require a mandatory 10% biodiversity net gain under the Environment Act 2021.
Local planning authorities expect clear baseline data, a defensible Metric 4.0 calculation and a proportionate uplift strategy before your application can progress.
Across London, planners regularly tailor evidence expectations to the capital’s complex urban landscape:
river corridors along the Thames and its tributaries
redevelopment of brownfield and intensification sites
interconnected green spaces and urban habitats
historic parkland and mature boundary planting
rail, road and canal corridors with ecological value
outer-London growth and redevelopment zones
Early clarity on baseline conditions and achievable enhancement is key to maintaining a defensible application.
We support schemes across Greater London, working in inner and outer boroughs as well as adjoining neighbourhoods.
Why planning officers in London request BNG Assessments
London LPAs request BNG evidence early because many developments sit close to watercourses, settlement edges or regeneration land, where small layout changes can noticeably affect habitat value and connectivity.
Officers want verified baseline habitats and clear Metric 4.0 scoring before designs progress, so uplift options can be understood without late-stage compromise. The county’s focus on canal corridors, historic field patterns and woodland-edge mosaics also means uplift feasibility needs to be established upfront.
Early Indicators Your London Site May Need BNG Evidence
On the ground, site-level features signal when BNG evidence will be needed:
- semi-improved grassland or species-rich margins
- hedgerows that link into wider networks
- wet ditches, streams or floodplain edges
- brownfield mosaics with herb-rich patches
- woodland edges or scattered trees
- PEA recommendations for botanical verification
- layout changes affecting habitat parcels
Providing this clarity early prevents validation queries, redesign instructions and delays during casework.
BNG Requirements — Delivered in a Predictable Sequence
We produce planning-ready BNG Assessments aligned to London’s policy expectations.
Case Insight
What We Deliver for London Projects
Every report includes:
verified UKHab habitat mapping
defensible condition and distinctiveness scoring
full DEFRA Metric 4.0 calculation
uplift strategy shaped around LPA priorities
integration with layout, drainage and protected species
clear, structured reporting for validation and negotiation
Step 1
Habitat baseline surveys
Year-round, with botanical elements best May–September.
Step 2
Metric 4.0 calculations
Completed once habitat data is verified.
Step 3
Uplift strategy development
Aligned with design progression and layout refinement.
Step 4
Integration with PEA, EIA or protected species
Used where additional clarity is needed around baseline or constraints.
Our approach keeps evidence proportionate, technically robust and predictable through the full planning sequence.
Next Steps
Contact us and we’ll confirm exactly what your site requires and support a planning-ready, proportionate route forward.
FAQ - BNG in London
Is a Biodiversity Net Gain assessment required for developments in London?
Yes. Where development falls within the statutory scope of Biodiversity Net Gain legislation, applicants must demonstrate at least 10 percent measurable uplift using the statutory Biodiversity Metric as part of the planning submission.
Does each London borough apply Biodiversity Net Gain in the same way?
The statutory requirement is national, but borough level validation requirements and planning expectations can vary. The BNG assessment must align with the relevant borough’s planning documentation and submission standards.
How is biodiversity net gain calculated on high density London sites?
Baseline habitats are mapped and assessed using the Biodiversity Metric. The post development layout is then modelled to confirm whether measures such as green roofs, podium planting and tree strategies achieve the required uplift in habitat units.
How does the Urban Greening Factor interact with Biodiversity Net Gain?
Urban Greening Factor requirements are separate planning policy tools. While some features may contribute to both, the BNG assessment must independently demonstrate measurable uplift using the Biodiversity Metric.
Are estate regeneration schemes subject to Biodiversity Net Gain?
Yes. Redevelopment of housing estates must quantify existing habitat value, including grassed areas and trees, before modelling new layouts to ensure the 10 percent requirement is met.
Can tall building schemes realistically achieve 10 percent uplift on site?
Achieving uplift on constrained vertical sites can be challenging. Roof habitats, terraces and tree planting may contribute, but careful metric modelling is required to avoid unit shortfalls.
How are Thames frontage developments assessed?
Sites adjacent to the River Thames may include riparian habitats or contribute to ecological connectivity. The baseline must accurately classify any associated habitats and reflect their value within the assessment.
What are common causes of BNG shortfalls in London?
Shortfalls often arise where baseline habitat value is underestimated or where roof and podium habitats are over specified without meeting Biodiversity Metric criteria. Early stage modelling reduces this risk.
Which authorities review BNG assessments in London?
Biodiversity Net Gain assessments are reviewed by the relevant London borough council, such as Camden Council, Southwark Council, Tower Hamlets Council or the Royal Borough of Greenwich depending on site location.
Planning guidance for Camden Council can be accessed at:
https://www.camden.gov.uk/planning
How can ProHort support Biodiversity Net Gain assessments in London?
ProHort undertakes detailed habitat surveys and robust Biodiversity Metric modelling tailored to London’s high density planning context. We work with architects and planning consultants to optimise layouts, reduce biodiversity unit deficits and provide clear, defensible calculations for submission.
