It's bad from the outside, but the inside is so much worse. And it gets worse the more you look at it. So many details that are just so awful. Living in this "house" is probably miserable.
Putting aside the wtf of it all, looking at the house subjectively, it would be a decent, possibly great, starter home.
The layout isn't entirely insane, there's a ton of space inside. It looks like the framing isn't half bad.... To my untrained eye, it has good "bones". The interior design and aesthetic choices are questionable at best, even for the most "normal" looking areas, but buy a case of beer and invite your friends over for a weekend and get most of the interior ripped down, and drywall installed and painted, and you're off to a good start.
Don't get me wrong, it would be a monster task. 4000 sq ft of siding to rip out and replace? Hell. That sucks.
Replace a lot of the fixtures, mainly all the stupid ceiling fans, especially the ones so high up they won't do anything, install some forced air HVAC or at least upgrade the Air conditioner situation and you would be having a grand time living in this place.
I'd probably rip off most of the external siding too and replace that with something a bit more interesting too, but with all the money you'll save by this being so inexpensive (compared to more palatable houses that are similar in size) and you'd get yourself a pretty nice place.
That being said, as is, this place is at best, a lot of questionable choices, at worst, pure nightmare fuel.
My partner thinks it's a converted chicken coop. I can't say that they don't have a point on that one.
There's no room for insulation above the ceiling, no place to run ducts for central HVAC, and the rooms above the 2,000 sq ft garage will be extra hard to keep thermally regulated. This house is super expensive to keep comfortable, and I would bet the window AC units are not up to the task of regulating indoor humidity and the whole structure is a moldy biohazard.
I agree with your partner. This structure looks like it was originally designed for agricultural use. Maps show there's a farmers field a few lots up the road.