Biodiversity Net Gain (BNG): Light at the end of the tunnel for smaller sites
The requirement for development to deliver Biodiversity Net Gain (BNG) has been a requirement for smaller sites since April 2024 and it has been widely reported that this has caused some significant challenges as such sites often have less flexibility to deliver onsite gains.
Alister Smith MRICS head of the Planning and Design Team at Stags notes the real-world impacts of this observing that few smaller sites across the West Country have stalled due to BNG related challenges. This matter has now been recognised by the Government and follow consultation earlier in 2025. As part of ongoing BNG reforms, the UK Government is introducing a series of targeted exemptions aimed at reducing regulatory burdens. The main change of interest is that a new area-based exemption for developments on sites up to 0.2 hectares (0.49 acres) will be introduced.
What this means is:
• Small sites falling under this threshold will not be required to deliver BNG.
• This will remove the need for, biodiversity metric calculations, and habitat delivery obligations.
The exemption is designed to reduce disproportionate costs and delays that have been contributing to making some smaller developments unviable. No announcement has been made that would suggest existing exemptions, such as the allowing self-build developments of up to 9 homes, will be removed but the devil is often in the detail. As yet no firm date for introduction of the new threshold has been set but it is stated that further announcements will
be made in the new year, it would not be surprising if the changes do not take effect until late spring/early summer 2026.
These changes do not impact the need for BNG on larger sites or the need for wider ecological and species-specific surveys and Stags can advise on these aspects thanks to the recent appointment of Ecological Consultant Johanna Legg.
If you are navigating the challenges of Biodiversity Net Gain or want to understand how these proposed exemptions could affect your development, now is the time to seek expert advice. Contact Stags Professional Services on 01823 653424 to speak with your local planning specialist and get clear, practical guidance on how to move your project forward with confidence.
Alister Smith MRICS head of the Planning and Design Team at Stags notes the real-world impacts of this observing that few smaller sites across the West Country have stalled due to BNG related challenges. This matter has now been recognised by the Government and follow consultation earlier in 2025. As part of ongoing BNG reforms, the UK Government is introducing a series of targeted exemptions aimed at reducing regulatory burdens. The main change of interest is that a new area-based exemption for developments on sites up to 0.2 hectares (0.49 acres) will be introduced. 
