Understanding the difference between biodiversity units and biodiversity credits under the new biodiversity net gain legislation
The concept of biodiversity net gain (BNG) has gained significant traction with the implementation of new UK legislation requiring developments to achieve a 10% increase in biodiversity compared to pre-development levels. Central to this system are biodiversity units and biodiversity credits, terms often used interchangeably but representing distinct components of the BNG framework. Here, we unpack their meanings and roles in delivering meaningful ecological improvements.
What Are Biodiversity Units?
Biodiversity units are the primary currency for measuring changes in biodiversity value on a given site. They quantify the ecological worth of habitats based on their condition, area, and distinctiveness, as well as strategic significance. This measurement is achieved through the Biodiversity Metric, developed by Natural England, which standardises the calculation process.
Key features of biodiversity units:
Site-specific: Biodiversity units are tied to a specific piece of land. They represent the net change in biodiversity as a result of habitat loss, creation, or enhancement on that site.
Calculated using the Metric: The Biodiversity Metric assesses factors such as habitat type, condition, and location to assign a unit score to a development site.
On-site or off-site: Units can be generated or offset on-site (within the development boundary) or off-site (on other landholdings), depending on the nature of the project.
What Are Biodiversity Credits?
Biodiversity credits, on the other hand, are a financial mechanism designed to help developers meet their biodiversity net gain obligations when they cannot achieve the required uplift through on-site or off-site measures. Essentially, they offer a last-resort option, enabling developers to invest in strategic biodiversity projects elsewhere.
Key features of biodiversity credits:
Monetary transactions: Unlike biodiversity units, credits represent a monetary contribution toward biodiversity improvement projects, often managed by the government or accredited organisations.
Fall-back option: Credits are intended to be used only when all reasonable on-site and off-site measures have been exhausted.
Centralised delivery: Funds from credits are typically allocated to large-scale conservation projects, ensuring biodiversity gains at a broader, landscape level.
Standardised pricing: Credit prices are set by government authorities to ensure transparency and fairness.
The Relationship Between Units and Credits
While biodiversity units focus on quantifiable ecological changes, biodiversity credits act as a supplementary tool to address gaps in delivery. The relationship between the two ensures flexibility within the BNG framework while maintaining the overarching goal of biodiversity enhancement. Developers must prioritise achieving net gain through biodiversity units before resorting to credits, aligning with the hierarchy of avoid, mitigate, and compensate.
Implications for Landowners and Developers
For landowners, biodiversity units present an opportunity to generate income by creating and managing habitats that generate units for sale to developers. This supports landscape-scale conservation and fosters partnerships between stakeholders.
For developers, the introduction of biodiversity credits underscores the importance of early ecological planning to minimise reliance on credits and reduce project costs. Integrating BNG considerations from the outset can streamline compliance and deliver more sustainable outcomes.
TOE has a strong portfolio of biodiversity units across the county providing local options for developers to meet their BNG requirements.