Change of use from A1 to B8 and subdivision of Unit with associated alts - Public forum - Planning Advisory Service (PAS)

Hi, I am new to CIL and I am looking at the above application and I am of the opinion that it is not CIL liable because it only involves the change of use and subdivision of the building which has been in lawful use for at least 6 months of the previous 3 years. Can anyone point me in the direction of which regulation backs this up as I can't seem to find anything?