I would like to suggest a new feature that will allow players (like myself) who own a Company House but not a Personal House (or visa versa) to purchase a new home in either category and default the original to the second category.
IE: Free Company owns a small house. Company leader would like to purchase a medium or large house for their company. Approach the placard and opt to purchase house with a check box if it is to replace the existing home (Free Company or Personal) and default the existing one to the opposite category.
That way I do not have to go through the painful relinquishing process in order to "upgrade" my Company house and retain the old one as a personal.
That being said, when upgrading the home it could use the same feature that relinquishing it does for Personal Rooms inside the house. If it is defaulted to personal from company, any rooms that existed in the house prior would have their contents dropped onto the NPC for pickup.
If anyone believes this idea to be a good one or has any further elaboration, please feel free to chime in.