2023-06-28-莱坊-Biodiversity_Net_Gain_Guide_June_2023_9页_228kb

Biodiversity Net Gain (BNG): England's New Mandatory Requirement

BNG requires new developments in England to achieve a measurable increase in biodiversity compared to their pre-development baseline. It became mandatory under the Environment Act 2021, effective from November 2023 for most developments, with later dates for small sites and national infrastructure projects (April 2024 and Nov 2025 respectively). All developments must deliver at least 10% net biodiversity gain, managed for at least 30 years.

Key Objectives and Drivers

• Biodiversity Decline: Reverse the decline in UK biodiversity (41% of surveyed species lost since the 1970s).
• Public Demand: Growing public concern and support for conservation is reflected in increased membership of conservation organizations.
• Broader Benefits: Enhance landscapes, preserve cultural sites, support climate mitigation through carbon storage, and provide educational/recreational opportunities.
• Legal Basis: BNG is enforceable through planning obligations and environmental impact assessments.

Implementation Details

• Exemptions: Small developments (<10 houses or <0.5ha), linear habitats below 25m², householder applications, and sites requiring minimal enhancement ("biodiversity gain sites") may be exempt or delayed.
• Calculations: Developers use the Natural England (NE) Biodiversity Metric (version 4.0) to assess habitat value and calculate required net gain via 'biodiversity units'.
• On-Site vs Off-Site: Prioritize on-site habitat creation or enhancement; off-site options require registration on the NE Biodiversity Gain Site Register. Statutory credits are a last resort.
• Long-Term Management: Gains must be secured through planning obligations or covenants for at least 30 years.
• Monitoring & Enforcement: Full details pending, but enforced via planning regimes and the Biodiversity Gain Site Register.

Requirements for Landowners and Developers

• Landowners: Can sell biodiversity units derived from land management activities if registered with NE.
• Developers: Must conduct baseline surveys using a 'competent person' (usually an ecologist), create plans for net gain, and ensure replacements are equivalent or better in quality and size.
• Existing Protections: Land legally protected from development must still comply with BNG regulations.
• Coordination with Other Schemes: BNG units can be combined with nutrient mitigation credits, but not selling other ecosystem services like carbon offsets on the same parcel without specific conditions.

Market Considerations

• Unit Valuation and Sales: Unit prices vary based on habitat priority and location, potentially reaching >£40,000. Landowners should understand risks, long-term costs, and inheritance tax impacts. Prices are expected to stabilize, but market factors will influence value.
• Credit Scheme: NE will introduce a 'last resort' credit scheme with intentionally uncompetitive pricing to encourage voluntary action.

Challenges & Concerns

• Reliability of Metrics: The NE metric does not account for indirect impacts, potentially requiring supplementary environmental impact assessments.
• Greenwashing: Public and investor pressure requires tangible proof of biodiversity success.
• Expertise Requirement: Accurate assessments require competent ecological knowledge to avoid delays or rework.

Who to Contact

Knight Frank offers advisory services for BNG projects in urban, rural, and mixed sectors. Key contacts include James Shepherd, Tom Heathcote, and Charlie Dugdale for related support.