Developers seeking consent for nationally significant infrastructure in England must now plan for at least a 10% biodiversity net gain, extending a central feature of planning law to the country’s largest projects.
The requirement applies to development consent order applications made on or after 2 November 2026. It covers onshore projects in England and relevant intertidal areas down to mean low water, while excluding marine development beyond that boundary. Hybrid bills follow a different parliamentary route and are not brought within the rule by this change.
Applicants must measure the project’s effect using the statutory biodiversity metric and set out how the minimum gain will be secured. The hierarchy favours habitat improvement on the development site, followed by registered off-site gains. Statutory biodiversity credits are intended as a last resort rather than a routine substitute for project-specific mitigation and enhancement.
The new biodiversity statements have legal effect within the national policy framework used to decide major infrastructure applications. They do not guarantee consent, and meeting the 10% figure does not displace other environmental assessment, habitats or planning requirements. Instead, biodiversity gain becomes an additional minimum outcome that must be addressed in the application and secured through the consent process.
The change is prospective, so it does not reopen applications validly made before the commencement date. Government guidance on the official commencement, scope and compliance route took effect on 2 November 2026.
