Is the setback of 10 feet for building in Hall county GA distance from the edge of the lot to the wall or to the edge of the roof?

Heck, it'd have to be from the roof overhang. You could build the roof overhang completely over the property line, onto the neighbors, if you wanted to. So, logically, it has to be the point closest to the property lline, hence, the roof overhang. I don't know about the "10 feet" rule, but, Im sure it refers to the part of the building closest to the line.