Biodiversity Net Gain (BNG) Regulations in England
Biodiversity Net Gain (BNG) is a mandatory requirement for most new developments in England, ensuring that the natural environment is measurably improved after development. The policy, introduced under the Environment Act 2021, aims to balance development with ecological restoration and long-term sustainability
What is Biodiversity Net Gain?
BNG requires developers to deliver at least a 10% improvement in biodiversity value compared to the pre-development state. This is measured using the government’s statutory biodiversity metric, which evaluates habitat size, type, quality, and location
Who Must Comply?
Major developments (from 12 February 2024)
Small sites (from 2 April 2024)
Nationally Significant Infrastructure Projects (from November 2025)
Land managers who wish to sell biodiversity units
Local planning authorities overseeing compliance
Exemptions
Some developments are exempt, including:
Certain permitted developments
Urgent Crown land
Some household applications
Developments below a de minimis threshold
How is BNG Achieved?
- On-site: Enhance or create habitats within the development boundary.
- Off-site: If on-site gain is insufficient, developers can create or enhance habitats elsewhere or purchase off-site biodiversity units.
- Statutory Credits: As a last resort, developers may buy credits from the government, which will fund habitat creation elsewhere in England
All new or improved habitats must be maintained for at least 30 years
The BNG Process
Baseline Assessment:
Biodiversity Gain Plan:
Delivery and Maintenance:
- Implement habitat enhancements as specified in the approved plan.
- Maintain and monitor these habitats for at least 30 years, providing regular reports as required.
Registration:
Special Considerations
Irreplaceable Habitats:
Strategic Significance:
Spatial Risk Multiplier:
Ongoing Policy Development
BNG regulations are evolving, with current government consultations focused on refining requirements for minor, medium, and brownfield developments, as well as nationally significant infrastructure projects.
Further Information
BNG is set out in the Environment Act 2021 and related regulations. For the latest updates and detailed guidance, visit the official GOV.UK BNG resource2.
Key BNG Requirements
| Requirement | Details |
|---|---|
| Minimum Net Gain | 10% increase in biodiversity value (statutory metric) |
| Legal Basis | Environment Act 2021, Town and Country Planning Act 1990, supporting regulations |
| Application Date | Major: 12 Feb 2024; Small sites: 2 Apr 2024; NSIPs: Nov 2025 |
| Delivery Hierarchy | On-site → Off-site → Statutory credits |
| Maintenance Period | Minimum 30 years |
| Exemptions | Certain minor, urgent, household, and de minimis developments |
| Administrative Requirements | Biodiversity Gain Plan, use of statutory metric, registration of off-site gains |
| Monitoring | Ongoing habitat management and monitoring for 30 years |
