You should probably spend a few bucks to talk to a local attorney familiar with real estate, it might save a lot of hassle down the road. They are building new homes adjacent to my property so I'm cc'ed on all the applications, etc. There's a lot of paperwork, approvals, inspections and they are being handled by an attorney specializing in this, plus an environmental company doing the studies and supervision. Of course this is probably mroe involved than your situation, but there's obviously a fair amount of complexity. I don't think this is a good do-it-yourself thing. If something isn't properly handled you probably won't even know about it. But then one day somebody could appear out of nowhere and tell you to tear down your house. Or (more likely) you won't have a clear title and won't be able to sell it.
In Skaneateles NY (not far from my other home) there was a high profile example. Someone built a new home without getting proper approval, resulting in a house that was too large for the site. We're talking about a big, expensive, luxury house - owned by a lawyer in fact. This went through the courts for several years, but just to prove a point the town actually made him tear down his house as a penalty for failing to get a proper permit. All the TV stations had it on film, pretty unbelievable.