I've been asked to move 2 CUs which are both compliant to 16th regs from basement to floors above (3 storey building used as shop and 2 rented business properties) so CUs are accessible to tennants should MCB / RCD blow. I'm planning to use 16mm feed to each floor from Switch Fuse in basement, but what I'm wondering is whether re-using existing CUs is compliant with regs or not, especially given that I will be altering circuit arrangements as a result of this work to re-connect to new CU positions???