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Compare As-Built Survey Points with Design Coordinates

Last updated 26 September 2026

Match what was shot against the design sheet station by station, flag anything outside tolerance, and save the comparison.

What it does

You have the design coordinates of the pegs, piles or bolts, and the as-built survey of what was actually built. The comparison matches them station by station and gives the difference in easting, northing, plan and level for each, flagging anything outside your tolerance.

Prepare the two sheets

  • The survey: your as-built points, loaded as usual.
  • The design sheet: a CSV or text file with STATION, EASTING and NORTHING columns, and ELEVATION if levels should be checked too. It must be on the same grid as the survey.
  • The same station names in both. Matching ignores upper and lower case and spaces at either end, but “P-01” and “P1” are different stations.

Step by step

  1. Load the survey in the web app or the Windows app.
  2. Open Against design in the section list and press Load design sheet.
  3. Set the Plan tolerance and Level tolerance in metres (0.050 and 0.030 to start with).
  4. Read the cards: how many are within tolerance, how many are outside, and how many survey points are not in the design. Points outside tolerance are listed worst first, with the plan difference and the shift in easting, northing and level.
  5. Press Save comparison sheet for a CSV with STATION, dE, dN, PLAN, dZ and OK or OUT for every matched point.

In Google Earth and the report

In the saved Google Earth file, points within tolerance get a green marker and points outside it a caution marker, and each point's balloon shows its differences. The comparison is also carried into the survey report (PDF).

Reading the differences

  • Every point off by about the same amount in the same direction usually means a setup or grid problem, not the construction: check the control, or whether both sheets are really on the same grid.
  • A few points far out are usually a wrong station name, a typing mistake in the design sheet, or genuinely misplaced work.
  • Many “not in the design” means the names don't match. Line up the naming first.

Run the quality checks too, to catch duplicates and level busts in the survey itself.

Try it with your own sheet

Open the web app Find your grid

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