house across the street from the one I grew up in
was miss placed by 5 feet

when the older house next door was built
they marked end the wall here at the property line
mason ended the wall there BUT
then built the 5 foot square end column into the next lot

30 years later when the new house was built on the property
they layed out the building by the wall end column

lucky for them the lot next on the other side to it was unbuilt and
the city had take a bite out of that lot to line up the street
so they bought a big side yard cheap
so we got a mostly open lot to play ball in

odd thing was years later the house had to be chopped off
to split the lot and build a mc-mansion on the empty lot
at that point the city had lost the never recorded bite
they took out of the lot to line up the street
as the guy who lived on the others side of the street declined to buy the
matching bit when the street was offset so the whole deal went in to limbo
for about 50 years
I tryed to get the city to see their error
as the new mc-mansion was built on city owned land in the new right of way
but nothing ever happened and desent guy bought the mc-mansion
so we let it drop

I'm not 100% sure what you just said but it's worth pointing out that if land goes used by another party uncontested for a period of time (IIRC it's 7 years in most places) there's an automatic right to deed based on squatters rights.

Another sr pm here....I feel your pain! Seems lately very difficult to find good surveyors....there's one or two firms here in NJ that I'd trust my career to...that's it.

There are several others but they seem to be "body shops" more than professional surveyors.

By the way, I don't agree with the design build comment made above....I think it's a positive change that's happening throughout the heavy construction industry.