Research by Carter Jonas has found that most local planning authorities have neither adopted a biodiversity net gain policy nor have one emerging in their local plan. Kieron Gregson looks at what they need to do to by the autumn

The implementation date for a minimum 10% biodiversity net gain (BNG) requirement on new developments – with a five-month grace period from the introduction of the BNG mandate for small sites – is fast approaching. In November, the transitional period ends and the requirement becomes mandatory.