is there an entity you have to submit drawings to for approval and permit issuance?

Haven't found such an entity yet, curtkram -- I've asked similar questions at the county level. 

I've done this before, we just adopted the IBC as far as building codes go and I believe the state fire marshal reviewed it but that was it. Someone at the county should be able to answer this i would think. 

i've worked with unincorprated towns, but i recall it's typically handled at the county level, which you already said doesn't apply.

i would call the mayor.  in a small enough town, the mayor is probably not a particularly prestigious position or anything, and they would likely know how the bureaucracy works better than anyone.

if the mayor doesn't give you any requirements, maybe make sure to not stamp or sign anything ever, and assume you can build without a permit.  i would still design to the 2012 ibc because that's just a good idea.

Check with the State Fire Marshall's office. They might be able to give you some advice as how to proceed from their position.  You might also might want to check with the State Building Official's office.  I'm sure they have run into this problem before, and have most likely developed some form of process as to how to proceed.  I would say  if there is a code that applies  to State Buildings which has been adopted, it would be best to follow those regulations so someone has a paper trail down the road.  Even if the local bodies have not adopted it you can at least you can say it was built to the States Standards for public buildings.

there is no there -- so you submitted plans to the State Fire Marshal -- I take it you had no building offiicial on site then?  So no cert. of. occupancy, etc.?

curtkram -- it's unincorporated, so there's no mayor.

Snooker -- sounds reasonable.  Probably the only point of possible contention from the client in going this route might possibly be compliance with the energy code which has been adopted at state level -- most of the area cities aren't enforcing this yet except on state buildings.   

If I remember correctly, there were a few guys at the county level that reviewed plans but it was informal and yes the state fire marshal reviewed the plans. I wasn't around when a certificate of occupancy was issued so couldn't tell you. What county? I would call them. Someone there will know the route. If there truly isn't anything like there might not be anything for energy codes, then they might defer to the licensed architect. 

I would assume that if there is no local or county involvement then the state's rules would be the default.  I can't see how the client can't comply with state energy (or any other) regulations since the state still has jurisdiction above and beyond any local laws.

Saint, I seem to recall there were county level building officials that did inspections. Following the IBC was good for them (via the state fire marshal's standards I suppose). They didn't have local variations or requirements, is that what you want to know?

we have done work like this before, usually the county hires an independent plan checker on your dime to check compliance with the current IBC.  Bad idea, to just assume you can do the work without a permit or without going through some sort of plan check process or approvals through the county.  The state fire marshal will also have to check the plans.  You just have to find the right contact in the county and ask them the adopted procedure for such work.