Converting Building to Self Storage

[Tom Scott]

Hi all, I'm investigating the possibility of converting a former big box store to self storage and I'm wondering if there are any basic rules of thumb to determine how much of a buildings space can be converted to storage vs the space used for reception areas utilities, hallways, etc. I'm also hoping to get a rough idea of how much on can expect to make per square foot of storage. 

Obviously these will all be very dependent on too many factors to mention but I'm just wanting to find a way to filter through some of the spaces so I can focus on those that will be the most profitable. 

Thanks in advance,

Tom