Okay, you didn't mention your EPs, but now we got that out of the way. There is a way you can create a "hotel" similar to how a dorm is set up.
Inge has several mods available at Simlogical to control access to different areas of a house or rather a building and grant access to certain types of Sims you can have visiting. They are an alternative to the apartment system if you don't have Apartment Life. I don't think Mansion & Garden has that.
Check it out
here to read about the door access system and how to use them to your advantage.
Hope this is something you had in mind.
