Government confirms forthcoming changes to Biodiversity Net Gain rules - CIEEM

The UK Government has published its response to a consultation on improving the implementation of Biodiversity Net Gain (BNG) for minor, medium and brownfield development, setting out a package of reforms expected to come into force before 31 July 2026 (subject to parliamentary scheduling).

BNG remains “widely considered to be a world-leading environmental policy”, and Government has reiterated that it “remains committed to BNG and recognises the importance of BNG in delivering nature-positive homes and infrastructure that this country needs.”

However, the response is primarily aimed at reducing burdens on developers (especially smaller ones) rather than strengthening outcomes for nature.

Key changes confirmed

Central to the reforms is the introduction of a new area-based exemption for sites of 0.2 hectares or below (except where priority habitats are present). Government expects this to exempt around 50% of residential planning permissions from BNG requirements.

This change is estimated to result in:

• around 12% fewer baseline biodiversity units being compensated for; and
• a reduction of around 10% in demand for off-site biodiversity units.

While Government considers these changes “proportionate” and argues that they will focus effort on larger developments with greater potential to deliver environmental benefits, the cumulative effect is likely to reduce overall gains for nature recovery.