California Surveyors Forums

I'm doing a topo survey of a corner lot and the minimum setback lines need to be shown on the drawing. It's a corner lot with a curve on the corner between the two tangents. How would you determine the min. setback line along the curve part, if one tangent side has a 12 foot setback and the other has a 20 foot side? Thanks.

Please see attached drawing.

I would contact the local agency

I did contact the City Planning Dept. and am waiting for a response.

PI the two tangents and show a radial distance from the curve. Let the architect figure it out

PS Put a note on the map that the setback's are not design setbacks and may change.

PL R - 12' = 27.99' setback radius

Seems logical to me that you transition from a 12' setback to a 20' setback..yes?

I agree with Paul about placing a prominant note on the map. The setback lines shown are based on an interepretation of the city planning code and may be revised after review by the governing agency.

Thanks guys. Paul, that does look like a reasonable determination. I'm going to call the planning department today. I may just leave that portion off and make a note.

MikeTurnrose wrote:Thanks guys. Paul, that does look like a reasonable determination. I'm going to call the planning department today. I may just leave that portion off and make a note.

Well...to simplify the whole thing just make it a 16' setback Mike. What I am
showing is a radial tie from the center of a 27.99' radius through the curve midpoint to the PL curve..but 20-12 = 8/2 = 4 + 12 = 16 feet which is the true mean.

Too easy Paul.

Mike, I think that you need to calculate a spiral curve with min radius of 12' and max of 20', show coordinates at the ends, the midpoint and at the 1/4 points, also indicating the dimension to the PL at each location.


Or, you can do what the architects do, slap a french curve on it, slide it around 'till it looks good and ink on a beautiful curve with no dimensions and no definite mathematical definition. That's on the hardcopy. Leave the CAD file with the missing linework. When the archy whines about, simply tell him that if the electronic file and the hardcopy differ, hold the hardcopy then quickly say "I've got another call, gotta go!" and hang up.

Some surveyors wait decades for an opportunity like that. Don't waste it!

Oh, I suppose I should add that I was just kidding... kind of.

I was going to provide Mike with the spiral answer but I dropped my french curve and broke it when I spilled coffee all over my hard copy..

Umm...gotta run..got another call!

Hold the 20' setback through the curve delta then a 90 degree 8' long line to the end of the 12' setback line.

Good one Evan. LOL