How hard is it to get permits to add 500-1000 sqft to a home in Historic Grant Park?

I'm currently looking for a solution, but this looks more for residential customers or consumers rather than real estate investors.  

They are a little more expensive, but their customer service is amazing and they are really responsive. 

I'm looking for a generality in time frames, types of permits most commonly used, etc.I spoke with Building Services for FTL earlier today, but they are now closed so I'm hoping your experience can help me as well. :) I see a trend through previous forums that a licensed GC is the only one that can pull permits on a home if it is not owner-occupied, I assume this is the case for FL as well?

I know I need to find out what type of contracts he has set up with the current customers.  

Don't know what the developers are pulling permits for 5 years out tho; I'd be curious to know that.

@Donna Capa,If they added 1000 square feet to the house then they should have gotten a building permit/building inspections etc.

One thing I worry about storage is having customers churn and never coming back after they realize that they could have just re-bought everything instead of keeping their items in storage for a few years... thoughts?

We got permits for it and had inspections. 

I'm at the point where I know I like this property enough but there could be some issues with building permits that aren't clear and some issues with (I don't know what the technical term is) possible tenant ... stuffing(?)