Just under six months ago a minimum 10% biodiversity net gain (BNG) requirement became mandatory for most residential planning applications.

BNG must now be considered at all stages of the development process, from validation through to assessment, discharge of conditions and reporting. One of the greatest challenges is the requirement to provide and manage BNG for 30 years: this has a significant impact on the management, financing and therefore viability.

In most cases, BNG will require a combination of onsite and offsite habitat creation and enhancement to meet the objectives set out in the Act. Net gain is measured, using Defra’s biodiversity metric, as the percentage change in the biodiversity value pre and post development.

Generally BNG has been accepted positively by the development sector, and many developments have achieved at least a 10% biodiversity uplift prior to the legal requirement to do so. Benefits range from ESG reporting to the added value, which comes from putting nature at the centre of housing developments.

Although initiated by the previous government, the introduction of BNG is well timed in view of the new government’s revised policy on Green Belt release. Not only is the provision of accessible green spaces one of the ‘golden rules’ required to achieve Green Belt release, but by providing BNG on low quality land in a new development, the ‘green’ criteria of the Green Belt can be strengthened.