I did some research and Charles didn’t actually move to Clarence House until 2003. He moved after his grandmother- the Queen Mother- passed away and they finished refurbishments. Before that he lived at St James’s Palace. I can’t find a confirmation that he moved there after the divorce so if anyone knows, reply to this post!! I think his intention was always to move to Clarence House but I don’t know that for certain
Isn’t Clarence House traditionally used for the heir to the throne? Then-Princess Elizabeth lived there with Philip, Charles, and Anne, before she became Queen. The Queen Mum lived there after George VI passed away. Charles moved to St. James Palace when he and Diana separated and lived there until he moved into Clarence House.