Biodiversity net gain (BNG) is an approach to development, and/or land management, that aims to leave the natural environment in a measurably better state than it was beforehand.
It is a way to contribute to the recovery of nature while developing land. It is making sure the habitat for wildlife is in a better state than it was before development.
New legislation will apply from January 2024 for developments in the Town and Country Planning Act 1990, of 10+ dwellings unless exempt and for smaller developments from April 2024.
What is Biodiversity Net Gain
Natural England and Footprint Ecology have produce this handy YouTube video which provides and introduction to the subject.