Blame it on the surveyors.

[JamesVincent]

This one falls under the LOLcopter, WTF file.

HAMMOCK DUNES, Fla. — A Missouri couple was devastated to learn their $680,000 dream home was built on the wrong lot inside a gated community in Florida.

“We are in total disbelief, just amazed this could happen,” Mark Voss, who owns a property management and real estate company in central Missouri, told The Daytona Beach News-Journal.

http://fox6now.com/2014/10/14/we-are-in ... wrong-lot/

[Pottapaug1938]

"Hey, Hon -- did we ever get an Owner's Policy of title insurance?"

[notorial dissent]

I think that one definitely qualifies as an oops of the very expensive variety. I'm not even sure title insurance would cover that since it was a builder error, better home he's well insured.

[Famspear]

I got this third hand, so I can't vouch for the accuracy of the story, but many years ago I believe someone started clearing a wooded area near the intersection of Barker Cypress Road and Clay Road on the west side of Houston before they realized that they didn't have clear title to the property. Fortunately the error was caught before any actual construction was commenced. I assume that it was all straightened out. Later, a big grocery store was built on the site.

[Randall]

In a past life (at least it seems that way) I was the City Clerk for a smallish city on one of Michigan's many lakes. I don't recall all the details but there was a dispute over property lines in one subdivision on the lake. The city agreed to have the entire sub resurveyed. The surveyors reported back after checking and rechecking and checking a third time. Bottom line was every lot line was off from what everyone thought they were. Some were just a few feet, other lot lines ran through the middle of houses. IIRC, they ultimately decided to adjust the lot lines to what everyone had assumed they were in the first place.

[Famspear]

In a past life (at least it seems that way) I was the City Clerk for a smallish city on one of Michigan's many lakes. I don't recall all the details but there was a dispute over property lines in one subdivision on the lake. The city agreed to have the entire sub resurveyed. The surveyors reported back after checking and rechecking and checking a third time. Bottom line was every lot line was off from what everyone thought they were. Some were just a few feet, other lot lines ran through the middle of houses. IIRC, they ultimately decided to adjust the lot lines to what everyone had assumed they were in the first place.

Whew! Man, I guess somebody in that case really had some serious " 'splainin' " to do!

[notorial dissent]

It's really fun when it's done based on old meets and bounds, and old mining claims, and the original survey was just plain sloppy to begin with.

[Duke2Earl]

There is a town in Western Maryland named Accident. The story goes that the name came from an "accident" made by 2 surveyors back in early times.

[fortinbras]

In terms of surveying errors, I suppose nothing can quite compare with that of Pierre Mechain (1744-1804), French astronomer and the leader of the enormous survey intended to determine the precise length of the new measurement called the meter. Just before the French revolution, he was commissioned by the King - and after the revolution his commission was reconfirmed by the Republic, to embark on the arduous task of establishing the exact distance between the North Pole and the Equator, passing through the meridian of Paris, so that the new "natural and apolitical" measurement of the "meter" could be set as absolutely exactly one-ten-millionth of the distance from the equator to the pole.

This required Mechain to embark on a journey that took him to the Dunkirk, at the northernmost coast of France, and then straight down to Barcelona, Spain, doing surveying that essentially repeated a similar project done ten years earlier. Among Mechain's difficulties was the fact that the previous survey had used various (usually very tall) landmarks for its sitings and by Mechain's time some of these had ceased to exist or had been changed so that the previous measurements could not be repeated. He was also using a new-fangled surveying device called the Borda Circles, which evidently used a new method of calculating angles - dividing right angles into 100 instead of 90 degrees. Even so, things appeared to be working fine until Mechain tried to take astronomical readings to verify his latitudes and some of the stars gave readings that entirely confirmed previous calculations and some stars appeared to differ from their old positions by a considerable difference. After that, Mechain was in a state of almost violent worry that all his calculations of distances were somehow wrong. This was even greater concern to him than the fact that, while he was in Spain measuring the distances to Barcelona, a war broke out between France and Spain and he was imprisoned for a while as a suspicious enemy alien. As a result he extended his project and held his calculations back from publication for years at a time.

In the end, his measurements and calculations were off by a microscopic error. The resulting meter gave a measurement, according to 21st century measurements by satellites, of a distance from equator to pole of about 10,000,229 meters. The 229 meters over such a great distance means that, for the length of just one meter there is an error of about one-fifth of a millimeter, very slightly more than the thickness of a human hair or somewhat smaller than a mustard seed. The length of 229 meters is about a mile and a third, or about half the length of NYC's Central Park, representing about ten minute's walk for a healthy adult. Considering this was an error in the measurement of the entire planet, most of us would say it was close enough for government work, especially considering that Mechain was working with equipment inferior to what a present-day Boy Scout could have.

[Judge Roy Bean]

Given the fact that the earth is not a perfect sphere, that level of "error" is incredibly small.

[Famspear]

....The length of 229 meters is about a mile and a third....

I believe 229 meters would come to about 250.4 yards, which would be about 0.142 mile.

[Famspear]

Speaking of surveys, I just recently had a survey done in the process of acquiring a piece of property in a rural area, and the surveyors rented time on some sort of GPS system. The GPS they used is much more accurate than the ones we use in cars, etc. If I remember correctly, the surveyor told me that they can get the accuracy down to within an inch, or maybe he said even a fraction of inch. Out of total survey bill of over $3,000, the GPS rental charge was $187.

I have only one GPS device (a plain old, hand-held Garmin), and it is supposedly accurate only to within about 40 feet or so. I bought it for my wife, and she never uses it.

[KickahaOta]

Speaking of surveys, I just recently had a survey done in the process of acquiring a piece of property in a rural area, and the surveyors rented time on some sort of GPS system. The GPS they used is much more accurate than the ones we use in cars, etc. If I remember correctly, the surveyor told me that they can get the accuracy down to within an inch, or maybe he said even a fraction of inch. Out of total survey bill of over $3,000, the GPS rental charge was $187.

I have only one GPS device (a plain old, hand-held Garmin), and it is supposedly accurate only to within about 40 feet or so. I bought it for my wife, and she never uses it.

Back in the 90s, it used to be that the non-military signals from the GPS satellites were intentionally degraded so that adversaries couldn't use them to target missiles. We pretty much gave up on that in the early 2000s. And, of course, as computing gets faster, it's easier to do the mathematical calculations needed to work out GPS locations.

These days, good-quality consumer level GPSes can be accurate to within 5 meters or less. (Of course, the GPSes in phones often aren't exactly good, but they're getting better.)

As you say, special surveying GPSes can be accurate down to a centimeter or two, but they aren't that accurate in real time. Basically, the main reason why GPS isn't exactly right is atmospheric variation -- the signals from the satellites get slightly deflected. This deflection varies by time and by area. So the surveying GPS takes the best possible measurements and records them. Meanwhile, special GPS tracking stations around the country are continuously taking GPS measurements and recording those too. Since the tracking stations are mounted to large buildings, you can pretty much count on them not to actually move. So, after the fact, the surveyor can feed the GPS data into a service that says "Okay, at that exact time the measurement was taken, the tracking stations near that site were recording GPS locations 2.43 meters south-southwest of where the stations actually were. So I can take this survey data, shift it 2.43 meters north-northeast, and that should be pretty much right on the money."

[fortinbras]

The book I had in mind was The Measure of All Things by Ken Alder (NY, The Free Press, 2002) - I glanced at it in a used bookstore, left and then turned the car around and went back and bought it. Also there was a novelized version of the same events, The Measure of All Things (Le Mesure du Monde) by Denis Guedj (France 1997, English: Univ. of Chicago Press, 2002). It is uncertain what caused Mechain's error but he was enormously concerned that while some of his astronomical sightings at several stars confirmed his latitude precisely, the additional sightings of some other stars showed substantial variances; the stars that gave Mechain trouble were very close to the horizon (when he asked other members of the surveying project at remote locations to sight the same stars they replied that they couldn't because those stars were too far south to be seen at their locations) and there may have been atmospheric distortion of Mechain's view.

The precise error (now that I have the book in front of me) was 2,290 meters [= 1.42 stat. miles] in the measurement from equator to pole. In US measurements, this means an error of 14½ inch per statute mile. In one meter an error of roughly 0.2 mm, a tad more than the thickness of one human hair (which is approx 0.16 mm) and considerably smaller than a mustard seed (approx 1.0 mm).

A worse error occurred with the Mars Climate Orbiter, which, rather than go into orbit around Mars, smashed into the planet in December 1998, because of computer programming that was feeding its calculations expressed in pounds-per-second into other computer programs that expected the numbers to be framed in metric measurements of newtons-per-second. The 750 pound spacecraft slammed into the surface of Mars with such force that we are lucky that the Martians didn't regard it as an act of war. I am sure the American taxpayers were thoroughly amused at how several billions of their tax money had been completely destroyed by the absence of about four or five lines of coding.