Do I need to hire a surveyor? Or is there a DIY GPS fix?

March 7, 2018 9:10 AM

With neighbors building fences and additions, I'd like to figure out exactly where my property lines are. I have various plats and maps from the county, and they have some longitude and latitude information, but is there a GPS-based way to determine the actual property lines on my own? Or do I need to pay the $1,000 + for a professional job?
posted by RandlePatrickMcMurphy to Home & Garden (13 answers total)

As GPS is at best accurate to about 16 feet gps is in no way suitable for actual property lines.

There might be original survey spikes still in place, and one could use rope to show the property lines, but that also assumes that you're trusting those spikes haven't been "accidentally" adjusted by an interested party. While it won't serve all of your property, if there's a neighbor putting up a new fence, you might be able to force them to get a survey.
posted by nobeagle at 9:19 AM on March 7, 2018 [4 favorites]

Are you looking for the ability to use your phone or Garmin, step outside and say "right here is the property line" ?

You've got the plats and surveys, and those should show the points of reference (the IRF -- Iron Rod Found -- is common, but not universal) and that's what's used for straight-line connections. A physical object is more useful and lasting.

(You say they are from the county -- did you get a survey done when you bought the house ?)
posted by k5.user at 9:20 AM on March 7, 2018 [2 favorites]

Is there a legal dispute, or just curiosity? If it's a legal dispute you absolutely need a professional.

I've done a casual finding of property lines using the Theodolite app. This lets you follow lines at angles, as is the way most US property lines are defined. Ie: not just lat/lon, but "305 ft along the 235 bearing from this other point". It was tricky but was good enough it let me then find the iron rods that were still sitting at my corners on a semi-rural property.
posted by Nelson at 11:02 AM on March 7, 2018 [1 favorite]

The $10,000K GPS we use at work is accurate to approximately 3 feet. When we need a precise measurement, we call the surveyor.

But like others said, the property boundaries are off a point of reference. If that point of reference still exists and is reasonably accurate, and you're not trying to use your measurements to tell neighbors where they can/can't build, see if you can find them. I doubt it would hold weight if there was an actual dispute - if you're concerned about legality or precision, call in the pros.
posted by DoubleLune at 11:19 AM on March 7, 2018 [1 favorite]

nobeagle: "As GPS is at best accurate to about 16 feet gps is in no way suitable for actual property lines.
"

Sub centimetre GPS has been a thing for decades; but you won't confidently have that in consumer equipment.

But what you are paying for when you hire a surveyor is legal confidence backed by their liability. Also depending on the local laws even physically locating the pins that exist in some jurisdictions may not delimit the edges of your property and a surveyor will be aware of those issues.
posted by Mitheral at 11:44 AM on March 7, 2018 [2 favorites]

You can rent survey grade RTK GPS kits for around $500/day that will be accurate to hundredths of a foot, but your surveying efforts won’t have the legal validity of a licensed surveyor (nor are most survey units user friendly for the beginner). As others have mentioned, you can often find the property corners yourself with at most a compass and tape measure. But if there are disputes or conflicts, paying a professional is the smart move.
posted by Dip Flash at 11:45 AM on March 7, 2018 [1 favorite]

Cheaper to rent, and more than adequate for most property surveys, would be a traditional total station, but those are typically even less user friendly.
posted by Dip Flash at 11:48 AM on March 7, 2018

Where I live, the city requires a survey as part of the permitting process for additions.

So your neighbor may have gotten a survey done that would show your respective property lines.

Depending on your relationship with your neighbor, perhaps just ask?
posted by agog at 1:55 PM on March 7, 2018

You hire a surveyor. That's what's done.

I had my 1/2 acre with several buildings surveyed, staked and a recorded, stamped map for $650 (Western Washington). It's worth twice that in peace of mind, and it's the only thing you can do.

I'd ask a real estate friend or acquaintance for a recommendation. The planning department may also have a list. They're cautious though because of conflict of interest. You can go to the recorder's office and pull any recorded surveys adjacent to you and contact that surveyor.
posted by humboldt32 at 4:02 PM on March 7, 2018 [2 favorites]

Get a survey. If your neighbour builds on your land, they will have to pay the costs of removing what they've built, and restoring the property. Without a proper survey you may not have a leg to stand on. Consult a lawyer. But if you're really serious, get a survey. Cost of peace-of mind? Priceless.
posted by Enid Lareg at 4:06 PM on March 7, 2018

As everyone else has said, you hire a surveyor. And you pay a lot for their time because they're also taking on liablity.

To further explain the GPS issues: There are GPS technologies that can get within a few centimeters (if you spend enough money and have a fixed base station that can "dwell" for a month or three), but that doesn't help you for two reasons:

1. Remember that 2011 earthquake and tsunami in Japan? Japan's coastline shifted by 8 feet, and probably shifted the earth's axis by about 17cm at the poles. That was a dramatic shift, but the earth moves a lot, sometimes with earthquakes, sometimes with local slumping, and latitude and longitude move around relative to the earth's surface. It doesn't seem like much, but in my town fence permitting changes on the property line vs 3" off of it. It isn't reasonable that an earthquake happens and suddenly your fence line is a foot into your neighbor's yard, ground truth matters.
2. The legal definition of your land is based on distance and bearing from a reference point, so those numbers would have to be converted into latitude and longitude. This is a task fraught with problems (for one thing there are over 100 different oblate spheroids to approximate the earth's surface in use today, depending on where you are) and no local municipality is going to work in that converted space.

posted by straw at 4:49 PM on March 7, 2018 [3 favorites]

If you just want to know where the property lines are, a surveyor can send a field crew out to find the pins and mark the lines for a lot less than $1000. For reference, it cost me $300 to have stakes put on the corners and every 50ft down each side of a 1.5 acre rocky, hilly, brushy lot.
posted by bradf at 9:02 PM on March 7, 2018

Response by poster: Readers, I hired a surveyor. It cost $800.
posted by RandlePatrickMcMurphy at 11:45 AM on March 14, 2018 [3 favorites]