Government consults on easing Biodiversity Net Gain rules for small housing sites

The UK Government has launched an eight week consultation on proposals to ease Biodiversity Net Gain (BNG) rules for small-scale housing developments, as part of wider efforts to speed up housebuilding and support smaller developers.

What is BNG?

BNG became a mandatory part of the planning system in England in 2024, requiring most new developments to deliver at least a 10% improvement in biodiversity, measured against pre-development conditions. This can be achieved through habitat creation on-site such as metroSTOR’s green roof structures, off-site enhancements or the purchase of biodiversity credits.

Why the change?

Ministers say the current rules impose disproportionate costs and complexity on small and medium-sized enterprises (SMEs), especially in urban areas where space for habitat creation is limited. Developments of up to nine homes, currently subject to the same rules as major schemes, account for the majority of residential applications.

The consultation proposes lighter requirements for these small sites and the introduction of a new category for ‘medium-sized’ developments (10 to 49 homes), with reduced obligations compared to large projects.

While the government claims the move will level the playing field for SME builders, environmental groups have raised concerns that weakening the rules could undermine the policy’s purpose. Critics warn it could lead to “nature-positive” planning becoming the exception rather than the norm and that developers may exploit loopholes to avoid compliance.

Outcomes from the consultation are expected later this year.