Some here are comparing apples to oranges. I see you list Michigan in your info. Not sure if where you're at is rural, urban, or somewhere in between. But it varies greatly on what's required in different areas.
If you can, contact the local agency that has jurisdiction in these matters ,and anonymously inquire. No sense in waking up a sleeping giant, just yet.
But to give you some sort of an idea, I too live in the midwest, but in a very rural area. About 18 years ago, I initiated the ground work for my garage. I contacted the local village board and made the necessary inquiries. It was all pretty informal, to say the least. To be on the safe side, I also checked with the county offices, and they said I all I had to satisfy, was the village board's requirements. The particular person I had to deal with was the village treasurer... which happened to be a family relative. Paid a $25 for a building permit, and that's all I was required to do.
Nothing else. No approval process, no initial inspection, no electrical, no gas, no structural, no ground inspections, nothing... ever. The only time it gets slightly more involved, is if you are not doing the work yourself. Fortunately, I've worked in the trades for most of my life, so I'm very familiar with codes and procedures, so I adhered to those on every aspect. A close friend (who also lives about an 1/8th mile away) works for the gas and power company, so he showed me what I had to do for the gas line into the garage, and the connection for electricity. My garage is 40' x 30', has 9' ceilings, two 7' x 8' overhead doors, gas furnace, and 200 amp service. Both the gas and the electricity are independent of the house.
But I would imagine it would be pretty easy for some hack to throw up a building around here. Then again, maybe they know who the hacks are and enforce limitations and restrictions a little tighter on those guys.
My point is; it greatly varies what you are required to do from one area to another. In metropolitan areas, I know for a fact, it's much tighter. In rural areas, it's much more relaxed.