Obviously someone is wrong or confused. My bet is that the surveyor is correct as his license is always on the line regarding errors.
Sounds as if you are making all the right moves.

If he didn't make a mistake, then we did and I will be a different kind of worried..... Sigh. And the fun begins...

Are the builders laying out the foundation measuring back from the correct setback line? My thought is it's been surveyed and looks good on the drawing, I would question the ground measuring.

Did the surveyor stake the property lines in the field? If so, was it not possible to check the dimensions in the field?

"If he didn't make a mistake, then we did and I will be a different kind of worried..... "

YOU did the measuring for the foundation placement?

They measured and remeasured.

"They" sounds like the foundation guys. Or maybe not.

I've built many houses. The start is the same: from the surveyor's pins. And even those I double check to be sure hipster vandals haven't moved them for the creative joy of it.

Have the surveyors check what you've done. Surveying is not a diy job.

Are you on a slope?

We are measuring off the surveyor pins. They are drilled in to the asphalt, so no moving. It's on kind of a slope (kind of), but not 18" worth, and we had laser, so not ground measuring. We are trying to call the surveyor out to straighten it all out and have them locate the corner and clarify the setback location. This was an expansion of an existing structure, so we didn't measure off the surveyor pins at first, just off the existing. Only when we were double checking everything did we find the problem.

And, to clarify, "we" is not me :). We are our own GC and doing some of the work ourselves since there is a ton of knowledge and experience in the family (not me--my job is picking out finishes and stressing about the build). In this case, we hired people to help with the foundation and prep. Everyone is baffled.

So we'll see.

You are asking strangers on the internet to guess what went wrong and asking who would pay for errors before getting the opinion of the surveyor. You need to settle down and not jump the gun; you are likely to have many more of these kinds of problems before the project is completed.

An old construction supervisor once told me he preferred to speak of such situations as "opportunities" instead of "problems". He appeared to love "opportunities" and his fearless calm demeanor in the face of difficulty reduced the stress on the project team and led to some interesting solutions. Another word of unsolicited advice: you need everyone's assistance so don't think about who might be financially responsible until the issue has been resolved.

Thank you everyone for giving me some ideas to think about as we wait for our surveyor to come out!

Renovator8--I appreciate advice, solicited or not. I'm sure others can empathize as they look back to their first time undertaking such a huge project. And I was just trying to be funny re: the money--personality doesn't always shine through in my written word. I fully realize (and am thankful!) we aren't there yet. But regardless, your advice is noted--thank you. I'm glad this forum is here to ask questions--even if you are strangers, you're more experienced than me, that's for sure! Your old construction supervisor sounds a lot like my husband -- hopefully he rubs off on me. In the grand scheme of things--there could be worse things and so I'm glad they are breaking me in gently to this ride.

I lived in a neighborhood that ran into something like this.
Long story short the entire neighborhood was off by about eight feet and everyone just accepted it and we by and large drew our own lines with regard to fencing and mowing etc.

The lines the surveyors laid ran right through my next door neighbors garage, and his ran into his neighbors and so on right down the street.

Unless your surveyor is old and very familiar with the area they might not know these odd quirks in old neighborhoods.
I'd be talking to some long term residents and see if there are similar stories.

Yeah, if it's an old neighbourhood, then the survey lines are going to be way off. The equipment they used 100+ years ago to mark out property boundaries wasn't as accurate as we expect today. Lots of cities have older neighbourhoods where the whole block is off, and houses are built on neighbours' land, and that neighbour's house is built on the next neighbour's land, etc...

In a case like that, I would ask for an exemption to build within your setback. If all your neighbours are closer to the street or alley, then setting your house further in is going to look silly.

You know what? You may be on to something. Bells are ringing about something else happening a number of years ago which led to us figuring that our fence was in our neighbor's property line (has been for decades--way before we bought). I totally forgot about this. The neighborhood is very old and was at one time unincorporated (I don't know if that matters--maybe looser requirements? Who knows.). Very good idea. So I just got off the phone with my husband to ask him about this idea and JACKPOT. He thinks this may be it. Thank you!!

If your fence has been long-established, look into the rules/laws in your area for "take-over". In many areas, after a certain number of years of an "established" (un-contested) property "line" like a fence, that fence becomes the legal property line. I think 7 years is often cited in my area, but I've heard as few as 1... Maybe check into that.

And, then, if you discover that to be the case, find out what you need to go to get it RECORDED as such so that you or future homeowners/neighbors don't have to fight about it!

It's "adverse possession". And how and whether it applies depends on the jurisdiction and the particulars of the situation.

Unfortunately, the OP's case so far is as clear as mud. Though it will be interesting to see how it's resolved.

Well, the surveyor just left. He messed up. His offsets were not right and so his CAD is 18" off. So that's that. The fence line is pretty much exactly on the property line.

Just wanted to note regarding the accuracy issue... I'm involved in the survey side of things and more often than not, i'm absolutely blown away by the accuracy the surveyors were able to achieve when pioneering... I've tied into existing legal pins dated as early as 1904 with accuracy of about 1" with the most modern survey equipment available.

Of course... mistakes do happen and surveyors are no exception..it's just a tough one to make a mistake with as usually everything else is based upon that particular survey, mistakes and all.

Sounds like you will get a resolution to your case... good luck!

In my area in 1935, a governmental body bought up huge tracts of property and had it carefully surveyed. The property was eventually sold back to the civilian population during and after WWII. Those granite markers, where they still exist, are completely trusted by today's surveyors.

Thanks for the real phrase, worthy. I just knew the concept, not the term.

I once had a surveyor off more than a foot on the "cut" (depth of the excavation). My wife at the time thought something was off, but the surveyor insisted he was right. I ended up adding two rows of 10" blocks on top of the poured foundation; this, in turn meant reducing the roof slope to stay within the height by-law limit.

You should always let all professionals involved provide input before going to panic mode. There will be ample opportunity for that later.

It takes a long time to design and build a building and there will always be mistakes and bad luck; you must learn to not fear the inevitable.

What was his mistake? Was it something he should have reasonably caught or based on some really arcane hangover from years past?

The whole foundation of the surveying profession is accuracy. A mistake like this sounds like (careless rather than arcane), is kind of like a chef deciding to use salt when they run out of sugar.

At a minimum I'd think you'd want the surveyor to cover the expense of another surveyor of your choice doing a secondary check on his work so that you'll have confidence in what's happening.

You should also check on what they used for beginning reference points and make sure that these are sufficient. In laying out bikeways we've had surveyors go a quarter mile (or more) away to insure that they're working off of accurate points. What we don't need is some homeowner coming after us later saying that a bikeway is on their property and not within an easement.

It was his mistake but I wasn't completely clear on why the mistake happened other than "his offsets were 18" off". In order to not have to modify our plans, we are moving the whole house 18" over. He staked the whole house out and is writing a letter to the city certifying that the new location is acceptable. I didn't even think about having him pay for a double check, but that sound great. I originally thought the letter would cover it. I just kind of wanted it to be over and to move on. Should I press the issue? We do have fence lines and we will still be the required 8ft from the fence, so if there IS still a problem, at least it will be buried and not obvious.

A professional surveyor is obligated to correct his mistakes and pay for any damages resulting from his mistakes. Normally, that would not include paying for another survey. It sounds like the surveyor has corrected the mistake at his expense and he is also assisting with informing the municipality. I think the surveyor has fulfilled his professional obligation.

Trying to find and verify a surveyor's reference points may be a frustrating experience unless you have the correct equipment and, more importantly, a good understanding of surveying methods and concepts. A surveyor is often presented with options, and with each option, there is always some level of error. The challenge for the surveyor is selecting the option that has the least amount of error necessary for the task, and then managing the error distribution in an equitable manner. Therefore, trying to verify the surveyor's work without the proper equipment, training and knowledge may leave you very frustrated.

All surveyors make mistakes. Every surveying project is a minefield of potential mistakes, and professional surveyors do their very best to sidestep every potential mistake. But, no surveyor is immune to mistakes. Your surveyor came back and fixed the problem, and is taking the extra effort of working with the municipality. I'm sure that the surveyor made very, very sure that he did not make another mistake. I would recommend putting this issue behind you and moving forward with your project, with the assurance that your surveyor has corrected his error.