From 6 August 2026, several important changes to Biodiversity Net Gain (BNG) exemptions will come into effect, following updates announced by the UK Government.
The changes are expected to reduce the number of developments requiring BNG assessments, particularly smaller schemes, while ensuring priority habitats continue to receive protection.
Small Sites Exemption
BNG will no longer apply to planning applications where the total site area within the red line boundary is 0.2 hectares or less.
This change is intended to simplify the planning process for many small-scale developments by removing the requirement to demonstrate Biodiversity Net Gain.
'De Minimis' Exemption
A new de minimis exemption will also be introduced, meaning BNG will not apply where development affects less than:
- 25m² of on-site habitat within the red line boundary, or
- 5 metres of on-site linear habitat, such as hedgerows.
Temporary Developments
Developments that are entirely temporary will also be exempt from BNG where planning permission is granted for five years or less.
Priority Habitats Remain Protected
Importantly, these exemptions do not apply where development affects a priority habitat. In these circumstances, Biodiversity Net Gain requirements must still be met, regardless of the site's size or the extent of habitat affected.
Changes to Self-Build and Custom Build Exemptions
The existing exemption for self-build and custom build developments will be withdrawn for new planning applications submitted after 6 August 2026.
However, exemptions will continue to apply where:
- the planning application was submitted before 6 August 2026; or
- a variation application is submitted after that date and the original planning permission was exempt.
What Does This Mean for Developers?
These changes are likely to reduce the number of developments that require BNG assessments, particularly smaller residential and commercial schemes. However, determining whether an exemption applies is not always straightforward, particularly where habitat types or site boundaries are involved.
Developers, landowners and project teams with schemes currently being prepared should consider how the new rules may affect their planning strategy and whether the timing of an application could influence the requirements.
If you're unsure whether your development will qualify for an exemption, or would like advice on the most appropriate route forward, STAT Planning can help you understand the changes and guide you through the planning process.