Having owned several lots, I can assure you that a “reasonable” owner or builder is very careful to make sure searching county records, looking at development plats and getting a survey when it matters is just good practice. It’s amazion how many folks pay no attention to assuring that they have clear title and know with sufficiant precision [10 or 20 ft is good enough perhaps if you are not building anywhere near and no one else is building anywhere near that boundary. If you have to stay outside of setbacks or easements then a few inches matters] where all of their property boundaries lie.
We had an issue with a project we did last year. The detached garage had been built w/o benefit of permits sometime in the '80's. We were converting the attached garage into a living room.
The clerk asked the distance from the detached building to the attached. It was 4.5 ft. (5.5 ft. was the minimum acceptable distance).
He gave us a choice, tear down the unpermitted building, or tear down the wall, only to build a new wall one foot further away. We lost one foot of the new living room. The decision was easy, and by rights he did not have to 'grandfather' in the unpermitted garage.
From time to time they get burned.
Exactly. The plot plan would have shown the footings layout based upon the setbacks
The subdivision plat map would have shown the location of the lots they were to build on.
The local building inspector should have caught this as well.