Only slipped another month, but 12 February 2024 is now the date when BNG will be mandatory for new planning applications for major development made under the Town and Country Planning Act (TCPA) 1990. Major development includes residential developments with 10 or more dwellings, or where the site area is greater than 0.5 hectares. BNG for small sites will have the transition period extended to 2 April 2024.