Where are construction setbacks measured from?

March 1, 2009 12:28 PM

When a survey map and the real world differ, where are construction setbacks measured from?

I’m planning residential construction in rural Pepin country, Wisconsin USA. In preparation I had a survey made by a licensed land surveyor. They placed metal pins at the property corners and created a survey map showing property boundaries. The map also shows the centerline and right-of-way lines of the town road we have frontage on (and driveway access to).

I have to obey setback requirements from this road. The setback code reads: “30 feet from the right of way or sixty-three feet from the road centerline, whichever is greater.”

The confusion: what the map indicates as the center of the road seems several feet off from what appears to be the center of the as-built, IRL pavement. Adding to this confusion, this is a low-maintenance country road of macadam with indistinct edges. So, when it comes time for the inspector to verify that I’m following the required setback, what will he/she measure from? Will they just “eye” the pavement? Or will the existence of my map of survey take precedence?

Yes, I realize the answer ultimately lies with the authority having jurisdiction. But I would welcome insights and anecdotes to prepare me for that conversation. For various reasons the site restrictions are quite tight and I need every foot I can get!

posted by werkzeuger to law & government (5 answers total)

What they'll probably actually do is measure from your property line when it comes right down to it, unless there are actually survey monuments located within the street (which is entirely possible). The pavement really means nothing; that's just where the road ended up being in the city's right-of-way (ROW). The setback measurement that uses the street centerline as it's basis will almost undoubtedly be measured from the centerline of the ROW, not the street. But to be sure, that's really just a simple question for your local building department to answer. Just call them up and ask if the street centerline measurement is taken from the actual street or the center of the ROW.

What they'll probably do in the field is just measure how far your construction is from your own property line (which you'll proabably have to show dimensioned on your site plan anyway), and then add on the distance from centerline if the street is narrow enough to meet that requirement. So, if the ROW is only 30 feet, you'll have to be 48 feet off your property line.

In my area, there are quite a few places where there are county-maintained roads, but there is no actual ROW for the roads, just lines dividing neighboring properties and road easements, sometimes with the roads completely within one property. The distinction in your local code is probably to deal with situations like that.
posted by LionIndex at 1:43 PM on March 1, 2009

Have you asked your surveyor this question? There's a reason they are licensed, after all.

Some clarification would also help here. You are referring to the map done by the surveyor? And when you state "appears to be" what exactly do you mean? Appearance based on looking at the map? The physical road? The position of your stakes?

Personally, I am betting on the stakes. And my experience suggests that these things become a problem* only when the neighbors might have reason to object -- e.g. you've cantilevered your bedroom room over their fence -- or if is in obvious non-conformance with neighboring structures.

*Wetlands would also be a red flag.
posted by Dick Paris at 6:40 PM on March 1, 2009

Thanks for responses so far. It's hard to explain in words, so I appreciate people bearing with me.

Dick Paris: Yes, I'm referring to the stamped "map of survey" I received from the surveyor. It indicates the distance from the property corners to the ROW on each end of the property with frontage on the town road. Using the pin they set in the road, if I measure to what should be the centerline as shown on that map, I arrive at a point that doesn't look to be in the center of the paving, but rather several feet from the center.

I guess what I'm wondering is if there is a "theoretical" centerline of a road that can differ from the actual center followed by the road construction crew. And assuming that's the case, in a jurisdiction where setbacks are measured from a centerline, which is it? The real center of the road based on measuring pavement, or the centerline established by a surveyor?

BTW, this is a 40 acre (1/4 of 1/4 section) rural property, so neighbors aren't close. But setbacks are definitely observed in my area. No wetlands.
posted by werkzeuger at 10:09 AM on March 2, 2009

I guess what I'm wondering is if there is a "theoretical" centerline of a road that can differ from the actual center followed by the road construction crew. And assuming that's the case, in a jurisdiction where setbacks are measured from a centerline, which is it? The real center of the road based on measuring pavement, or the centerline established by a surveyor?

That's pretty much what I was addressing. The actual width of the pavement will, more likely than not, mean absolutely nothing. What if they come back and repave a couple years from now, but end up pushing the ashpalt a little more to one side than the other? It would be silly for your setbacks to change at that point. Note that your setback will be measured from the front property line anyway, unless the ROW is less than 66' wide.

Your city/county probably has a drawing somewhere that delineates the ROW on it, with the centerline shown right in the middle.
posted by LionIndex at 10:34 AM on March 2, 2009

LionIndex: thanks for the clarification. Your point about changing pavement widths makes sense. Since my survey map shows a centerline and the ROW, and was based on county survey mounuments, I'm feeling more confident using it for planning purposes. I'll be confirming it with the building dep't of course.

Bonus question: they recently resurfaced the road. I haven't been able to check if the property corner pin, which was pounded into the road, is still there. Was the road crew obligated to preserve it?
posted by werkzeuger at 1:24 PM on March 2, 2009