Biodiversity Net Gain (statutory)

In short

England's statutory regime: development must deliver at least a 10% net gain, measured in Defra statutory biodiversity units. Robust, and confined to England's geography.

What it is

Biodiversity Net Gain is a statutory requirement in England under which most new development must deliver a measurable improvement in biodiversity of at least 10 percent compared with the pre development baseline. Biodiversity value is calculated using the statutory biodiversity metric, which scores habitats by type, condition, size, and strategic significance to produce biodiversity units. Eligible activities include on site habitat retention, enhancement, and creation, and off site habitat works, with the gains secured and maintained for at least 30 years. One biodiversity unit represents a standardised measure of habitat value derived from the metric.

What it rewards

The reward is a credit called a Statutory Biodiversity Unit (BNG). One credit stands for one biodiversity unit (Defra metric). A verified, nature-positive biodiversity outcome. A whole period of work is issued as one batch of credits at a time, in the same way a registry issues a batch.

What gets measured

To earn BNG credits, a project has to measure and prove a few things. An independent reviewer checks the evidence before any credits are issued.

• Habitat type & distinctiveness. Distinctiveness is scored from habitat type (UKHab) and its features.

• Habitat condition. Condition is assessed against habitat-specific condition criteria.

• Habitat parcel area. A parcel is a linked area of one distinctiveness/condition/significance.

• Strategic significance. Location's significance to the local nature strategy.

• Connectivity. Connectivity adjusts the unit total.

Who takes part

• Standard Registry. Owns the policy, approves participants, anchors each issuance to its evidence.

• Project Proponent. Registers the project and submits monitoring reports.

• Validation & Verification Body. Independently validates the design and verifies monitored data.

How it works

1. 1

   The project team registers the project and its plan.

2. 2

   An independent reviewer checks that the plan is sound and that the benefit is real and would not have happened anyway.

3. 3

   The team looks after the site and measures the agreed indicators over time.

4. 4

   The independent reviewer verifies those measurements.

5. 5

   Credits are issued for the verified result, and a buyer can retire a credit to claim the benefit once.