I have submitted a planning application for a replacement residential dwelling (three bed bungalow being replaced with a five bed chalet bungalow - our sole residence) and as part of the condition of approving the application the local authority requires that we complete a Biodiversity Net Gain assessment. They said approval will be provided in Dec 2023. From what I understand the requirements for a BNG assessment has been pushed back until 2024. Is the local authority within its powers to ask for this prior to this becoming a legal requirement? Can they refuse the application if we don't complete one?