CIEEM Writes to Ministers Urging a Proportionate and Evidence-Led Approach to BNG Exemptions
CIEEM has today (11 December 2025) written to Government ministers across HM Treasury, MHCLG and Defra to express our concerns about the direction of travel on Biodiversity Net Gain (BNG) site threshold exemptions. In our letters, we strongly encourage Ministers to adopt a workable, proportionate and pragmatic approach that maintains the integrity of BNG while reducing unnecessary burdens on the smallest developers.
Recent indications that the Government is considering broad exemptions, including for all development sites under 0.5 ha, have raised significant concerns. Such wide-ranging exemptions risk undermining nature recovery, destabilising emerging private finance nature markets, and placing at risk the SME ecological consultancies and start-ups that have invested heavily in supporting BNG delivery.
CIEEM is clear that nature and development are not in conflict. With the right policy and evidence base, BNG can support better place-making, healthier communities, climate resilience and long-term economic value. However, any dilution of BNG requirements must be based on transparent analysis and must not compromise priority habitats or remove nature from the communities that need it most.
In our letters, we highlight the practical and evidence-supported alternative of a 0.1 ha exemption threshold, which would reduce burdens on the very smallest development sites (approximately 50,000 each year) whilst ensuring that BNG continues to function effectively and to attract much-needed private investment into nature recovery.
CIEEM stands ready to work with Ministers and officials to ensure BNG remains a credible and effective policy that benefits people, nature and the economy. We urge the Government to maintain an evidence-led approach in finalising its consultation response and to ensure that any changes strengthen, rather than weaken, the delivery of BNG across England.
Read the letters below: