Suggestions on how to improve Apartments and/or FC Private Chambers:
-Allow people the ability to upgrade their apartment and/or FC private chamber. Like increasing the size, increasing the item limit (s), adding a basement, and/or adding a second floor. Make each upgrade a major money sink, that all adds up to the price of buying a Medium House (or maybe even a mansion).
-Give them an outdoor space, like a balcony.
-IF you don't want to give them an outdoor space, at least give players a way to garden and crossbreed plants indoors. You could even limit it to one-per house/apartment/private chamber.