I remember using Inge's lockable doors way back in Sims 1 days, that's how I made my apartments. And also with Sims 2, until we got Apartment Life. I figure with the underwhelming-ness of apartments in Sims 3, that with Sims 4 they would mend their ways and go back to what truly worked - Sims 2. Hopefully they have improve on the coding that is in the game, and make it possible for us to have true apartments outside of SM. Until then, @"Livin in Sim" , I might try something similar to how you have things set up.