I cant say all rural townships have ordinances or regulations that would ban you from renting out on site storage BUT Id suspect you have just as many townships , counties there that have not over regulated such things but do know say if you wanted / found twenty acres then you should first find out if the property has a agricultural zoning or not ( in some places agricultural zoning means lower property taxes ( even if you say raised livestock to be sold for meat that might be enough to earn agricultural tax rate) next is to learn if the area has any restrictions for building sizes other than set back rules ( areas that are semi rural but adjacent to suburbia often begin to do things like townships becoming incorporated into cities often to avoid annexations but those places are the ones who may have been working on own ordinances that could be restrictive like things you find in urbanized areas) so your Ideal location would perhaps be a rural township but just make sure you learn what ords/ zoning rules apply to that land and that includes the type of septic system and how far it must be from your well head since it could really change your monthly cost if you ended up with land where the only septic system you could use would be holding tank only. last two things if you had to make sure you think about what you might do for a site plan if you are asked for one , planning on fencing that blocks the view or plantings that will grow quickly to help hide the storage area from street or neighbor views often can go along way to help get approval and learn what kind of extra insurance you might have to have incase a garage tenant were to be injured on your property and having them waive the right to sue you in your leases wont spare you eventually from someone trying and keep in mind there are jurors who are numb N enough to award injury money to knuckleheads who might be there to commit a crime at 2am but were properly greeted and taste tested by your lovely pet rover.