Storage Units on Site

[Ryan Smith]

So I did some searching and could not find any threads about this. Maybe I was searching the wrong words. Has anyone added storage units to their apartment buildings? Such as in extra space near the parking lot, or against the back wall of the complex? Is permitting usually necessary for this type of value add? I feel it has a huge return on investment if done correctly. I am trying to figure out what the extra costs associated would be that I am not thinking of. 

Thanks so much in advance.