Talk to the zoning officer first...generally that's the start. If they feel its out of their area than you'll either end up in front of the zoning board or sometimes the planning board. Once you get zoning straightened out (& that does need to happen first or all other points are mute) than you move onto the building dept. I would set up a mtg. with the building official ( he oversees all depts. in bldg.) ask that you have something a little different than the norm & would like to discuss it as a preliminary "sit-down" with the him, the building inspector (sometimes these are one in the same) and the fire Marshall/official. Have as much info as you can at your fingertips at that mtg. and ask the questions you need to know NOW to get a "vibe" on their reactions, answers, ideas & suggestions. Should give you a pretty good indicator all around of what your up against or if they seem to embrace your idea. You can fight them (thats a whole other topic) but try & win them over at the mtg. & things generally will go a whole lot smoother for you once your all on the same page. I have 22 years of dealing with zoning, planning & inspectors, and probably have some of the strictest codes & regs in the country here in NJ. It "ain't" ez here for sure but if it was..."everybody would be doing it...right?" Not sure where your located but I'll do what I can to help you thru the process.