Nice coop! Frankly, you have an uphill battle. The first hurdle is your HOA. The county will defer to them every time something like this comes up. A big reason the law is so draconian is the clout exerted by HOAs. If the whole HOA were to go to the board and ask for a change to apply to them, it might happen. While you’re getting the HOA on your side, I recommend you write to your supervisor. The overlay district was drawn specifically to allow chickens for the supervisors that were supportive, and prohibit them for those who weren’t. The more letters they get, the more likely they are to respond. For the .26 acre - we argued until we were blue that there shouldn’t be any property size limits, as it is allowed in small towns across the country – like Chicago, San Francisco, Miami, Atlanta, New York, etc. We lost. The 1 acre + agricultural or semi-rural zoning was the best we could get.