The Environment Bill received Royal Assent on 9 November 2021. By amending the Town & Country Planning Act the Environment Bill requires all planning applications to show a post development biodiversity net gain. By enshrining environmental principles into law, the Environment Act includes a requirement to meet a mandatory measurable (10%) increase in ecological value over baseline values on a completed development site.
The ecological value of a site is calculated both pre-development and post-development via ecological survey and design proposals. Scores for both pre- and post-development are calculated via a formula in a recognised metric, such as that devised by DEFRA.
The concept of BNG aims to halt biodiversity loss and restore ecological habitat value and networks.
A mandatory 10% increase in post development ecological value can be met, by designing the increase into post-development habitats, be it on-site or off, or a mixture of both. Alternatively, payments may be made to local authorities to off-set any losses when it is not feasible for a development to meet the 10% target for increase.