The new building regulations came into force for applications made on or after 15 June 2022. The new requirements will not apply to applications made prior to June 15, providing substantial building work has begun before 15 June 2023 on all aspects of the application. This gives 1 year’s grace to allow commencement. (Note: jobs need substantial start i.e. foundations dug and poured.)
Further information about those changes on the Part L and F extension and alterations booklet.