Building regulations may make a prescribed person or class of persons responsible (instead of F1building control authorities) for performing prescribed functions of F1building control authorities under or in connection with building regulations, and for that purpose may provide for a prescribed enactment relating to building regulations and a prescribed provision of such regulations to apply (with any prescribed modifications) in relation to a prescribed person or a person of a prescribed class as that enactment or provision applies in relation to a F2building control authority.