For rent apartments

Can there be a way to set certain rooms/ apartments on the lot as hidden/ not shared? 
I have my sims living in a apartment block with 17 apartments, with 6 units selected to be livable apartments (not using increase rental unit cap cheat because it glitches out my game so I can’t even open the lot) 

The unused apartments are just selected as shared, but can there be away to make this a no go zone for all sims on the lot that is blacked out like other apartments. I lock the door off but you can still see the apartments meaning it runs slower and bugs and glitches out. 
Or ideally just a way to increase the official unit cap without using the cheat and without it bugging out and glitch my game. Please