Biodiversity Net Gain is an approach to development that seeks to balance conservation and economic growth. It requires developers to ensure that the biodiversity associated with a site is increased by at least 10% after development has taken place. This is achieved by creating habitats and species that are not present in the area being developed. Biodiversity net gain is becoming increasingly important as the world faces climate and ecological crises.
Biodiverity net gain can be delivered through on-site, off-site or a combination of both. On-site biodiversity gains are made on the development site itself, within the planning boundary. Off-site gains are made on land outside the development site, registered as a biodiversity gain site and legally secured by a conservation covenant.
Preserving Nature’s Wealth: Understanding Biodiversity Net Gain
On-site biodiversity gains must be a significant increase over the on-site pre-development state, and are secured by either planning conditions, planning obligations or conservation covenants (or a combination). Defra’s Make on-site biodiversity gains guidance provides some useful guidelines for LPAs in assessing this.
Off-site biodiversity gains must be recorded on the biodiversity gain sites register, and be measured using a standardised metric published by Natural England. There are a number of guidance documents that help with this, including the Biological Impact Assessment guide and the National Ecological Framework methodology.
The metric that is used to measure off-site biodiversity gains must include not just species and ecosystems, but also landscape structure, ecological functionality, people’s uses of nature and the value of biodiversity. This is something that we will continue to work with the government and others on, as we strive to provide a consistent approach across England.
