Under the Environment Act 2021, planning permissions granted in England, with a few exemptions, will have to deliver at least 10% biodiversity net gain (BNG), with phased implementation starting from November 2023. BNG will be mandatory for most new major development under the Town and Country Planning Act 1990 from November this year, for minor development from April 2024 and for Nationally Significant Infrastructure Projects from 2025. The exact dates will be announced as soon as possible and are subject to parliamentary timings. The initial assessment of the additional burden mandatory BNG would place on local planning authorities was made in the BNG Impact Assessment in 2019: Net gain impact assessment. Subsequently Defra worked with the Association of Local Government Ecologists and the Association of Directors of Environment, Economy, Planning & Transport to undertake a survey of local planning authorities in 2021. This survey was aimed at securing a better understanding of the existing capacity, skills and preparedness of local authorities with respect to BNG and wider Environment Act 2021 measures. The survey outcomes have been published in a report, available at: Defra Science Search. The Government announced funding to support local authorities in England with preparation for mandatory BNG of £4.18 million and up to a further £16.71 million during the two-year transition period. Defra is also funding a project with the Planning Advisory Service to support local authorities in preparing for BNG.