Extra Space Utilization?

[Lucas Duce]

Hello B.P. Community,

A potential property I am looking to purchase sits on about 0.8 acres of land.  The property is a decent sized duplex at around 1,800 square feet tucked in one of the corners of the "L" shaped lot. Besides for a small cement parking area next to the building, about 70% of the remaining land is basically just an abandoned overgrown back yard.  Somehow being able to utilize this extra space would make this deal even better.  

I have been emailing back and forth with the county zoning department about trying to get this lot subdivided to potentially build another duplex or fourplex, but the representative at the county's office tells me that it can't be subdivided since the division wouldn't result in two 20,000 square feet lots (results in one lot being only about 18,000 square feet).  I asked about possibly being able to do storage units some how, and I was answered with the same short response that it won't be allowed.  Does anyone have any ideas on how to utilize this large amount of extra space if the county won't let me subdivide it?  Should I attempt to keep pushing the county to try to see what they can do?  I've heard of real estate investors building one or two storage units in their small back alley yards, I doubt they are subdivided that into a 20'x20' lot, so how are they doing this legally? Thanks in advance for any help/ideas!

- Lucas Duce