The Government has confirmed a number of changes to the Biodiversity Net Gain (BNG) regime for developments requiring planning permission under the Town and Country Planning Act. These amendments, introduced through new regulations, represent the first phase of the Government’s 2025 BNG consultation and subsequent response published earlier this year.
The new regulations will take effect from 6 August 2026 and introduce several important changes:
- New 0.2-hectare exemption: Developments on sites of 0.2 hectares or less will generally be exempt from the mandatory BNG requirement, provided they do not adversely affect onsite priority habitat.
- Temporary development exemption: Developments that are temporary in nature and where the land will be restored within five years or less will also be exempt from mandatory BNG, unless priority habitat is impacted.
- Greater flexibility for minor developments: Minor developments that remain subject to BNG requirements (for example, sites larger than 0.2 hectares) will be able to meet their biodiversity obligations through offsite measures without first demonstrating that onsite options have been exhausted.
- Removal of the self-build exemption: The existing exemption for self-build and custom-build developments will no longer apply, meaning these schemes may now be required to deliver mandatory BNG where applicable.
Alongside the regulations, the Government has published an Explanatory Memorandum, an updated Impact Assessment, and revised guidance to support the implementation of these changes.
The intention behind the reforms is to reduce the administrative burden on the smallest developments and local planning authorities, allowing greater focus on larger schemes that have the greatest potential to deliver meaningful biodiversity enhancements.
Although some smaller developments will no longer be required to achieve mandatory BNG, developers are still encouraged to incorporate biodiversity-friendly design wherever possible. In addition, all developments, including those exempt from mandatory BNG, will continue to be subject to existing planning policies and environmental protections. Local planning authorities will still apply the mitigation hierarchy and should refuse planning permission where significant biodiversity impacts cannot be appropriately avoided, mitigated or compensated.
Transitional arrangements
The changes will apply only to new planning applications submitted on or after 6 August 2026. Planning applications already submitted, together with existing planning permissions, will continue to be assessed under the current BNG requirements.
Further updates to Planning Practice Guidance are expected shortly to provide additional detail on how these changes should be implemented in practice.
How Acorus can help
Whether your project is exempt from mandatory Biodiversity Net Gain or still requires biodiversity enhancements, Acorus can help you understand what the new regulations mean for your development.
We work closely with a trusted network of experienced local and specialist ecologists across the UK to provide the ecological support your project needs. By coordinating the process on your behalf, we can help determine whether your development qualifies for an exemption, arrange the necessary ecological surveys and assessments, advise on biodiversity requirements, and source suitable offsite BNG solutions where these are needed.
Our aim is to provide a straightforward, coordinated service that keeps your project moving while ensuring compliance with the latest planning and environmental requirements.
If you have a forthcoming development or an existing project that may be affected by these changes, we’d be pleased to discuss your proposals and help you navigate the updated BNG requirements.
