In April, we discussed potential upcoming changes to Biodiversity Net Gain (BNG) exemptions. In July, the Government announced that the following changes will come into force on 6 August 2026:
• Removal of the existing exemption for self and custom build developments meaning such proposals will now be subject to mandatory BNG requirements where applicable.
• Introduction of a new 0.2 hectare exemption whereby developments on sites of 0.2 hectares or less will be exempt from mandatory BNG, provided that no priority habitat will be negatively impacted.
• Introduction of a new temporary development exemption for sites that will be reinstated within a period of 5 years or less, provided that no priority habitat will be negatively impacted.
• Modification to the BNG hierarchy for minor developments that remain subject to BNG to allow developers to go straight to off-site gains.
The changes will only apply to planning applications submitted on or after 6 August 2026. Applications submitted, or permissions granted, before this date will continue to be assessed under the existing BNG regulations.
The introduction of the 0.2 hectare exemption will remove mandatory BNG requirements for many smaller sites. However, the simultaneous removal of the self build and custom build exemption will mean that some schemes expected to be exempt may now fall within the scope of BNG. We have already encountered a proposal which would have qualified under the self build exemption that will not benefit from an exemption once the changes take effect.
Applicants should also be mindful that BNG is assessed against the entire red line boundary and that the 0.2 hectare exemption is disapplied where a development impacts a Priority Habitat. An impact is defined as occurring where a habitat is lost or degraded such that there is a decrease in its biodiversity value. There are also currently 56 types of Priority Habitat in England, including habitats that are common features of development sites, such as hedgerows and streams.
Early ecological input can help identify potential constraints, establish whether an exemption may apply, determine survey requirements and ensure biodiversity considerations are incorporated into the design process from the outset. This can help minimise project risk, avoid unnecessary costs and provide greater certainty over planning and BNG requirements.
If you require advice on BNG, then please do contact us. We have extensive experience of delivering BNG solutions. Our ecological services support applicants at all stages of the planning process, including ecological appraisals, habitat surveys, biodiversity metric calculations, baseline and proposed habitat plans, BNG assessments, landscape and ecological management plans, habitat management and monitoring plans and the preparation of Biodiversity Gain Plans.
