To secure planning permission, all new developments must be able to demonstrate a 10% increase (“net-gain”) in biodiversity. An ecologist will calculate (using a model produced by Defra/Natural England) the existing biodiversity value of the potential development site. The developer must then submit a plan to the local authority showing how it will deliver 110% of that biodiversity value after the development is completed, and maintain that biodiversity for a period of at least 30 years.
