Import a drawing

Read lot shapes out of a drawing or a parcel download, see what the file actually yields, and decide whether it becomes the site map.

An engineer's drawing knows where the lots are, and so does a parcel download from a county portal. This page reads that out of the file and shows you what it found before any of it becomes your map.

It reads DWG, DXF, GeoJSON, Shapefile, KML, KMZ and GeoPackage. File the drawing under the project in Documents and it appears here. Nothing is read until you press Analyse.

A drawing and a parcel download are not the same file

A CAD drawing is linework: thousands of line segments that may or may not join up into shapes, with lot numbers floating as text inside them. Reading one means closing the linework into rings and working out which number sits in which ring, and the share of the linework that closes is the single most useful number on this page.

A shapefile, a KML, a KMZ or a GeoPackage is already shapes. The rings are rings, so closure reads 100 percent because the file really is closed; the coordinate system is usually written into the file rather than guessed; and the lot number is a column on each shape rather than a label floating inside it, which cannot put a number in the wrong ring. The page says which of the two happened, under Lots matched by.

A parcel download is a legitimate source for a project with no engineer's drawing yet. It is worth knowing that a county's idea of a parcel boundary and your final plat are not always the same thing, which is why this page shows you the shapes before it asks.

Getting the files here

• A shapefile is three files (.shp, .dbf and .prj) and has to arrive zipped, with all three inside. Without the .prj PadFlow falls back to guessing the coordinate system from your project's jurisdiction, the same way it does for a drawing that does not say.
• A KMZ is a KML in a zip and reads identically.
• PadFlow will not open an archive containing another archive, or one whose file paths point outside it. Both are refused with a sentence rather than opened carefully.
• PDF plats are not read yet. File one and nothing happens.

Filing a .dwg, .dxf, .kml, .kmz, .gpkg, or a zip whose name says shapefile (parcels.shp.zip) raises a suggestion on this page. Any other readable file is still importable from here: press Analyse on it. It just does not nudge you, because the document store is nearly all PDFs and a suggestion on every one of them is a suggestion nobody reads.

The filename does not tell you anything

We measured four real drawings while building this, and the file with the best lot lines in the set was a gas plan. A construction set was next. A grading plan, which sounds like the most site-shaped file of the four, produced almost nothing: its linework does not close, so there are no lot shapes in it to find.

That is why this page measures and shows rather than importing quietly. You are not being asked to trust a filename, and neither is PadFlow.

What you see

• A preview. The shapes the drawing yields, drawn on a plain background. Filled shapes matched a lot on your project. Faint outlines are lot-sized shapes that matched nothing.
• The numbers. Closed lots, how many lot numbers were found and how many of them matched a lot on the project, what share of the linework closes into shapes, and what share of your register the drawing covers.
• Lots matched by, which is either the lot numbers labelled inside the shapes, which is what a CAD drawing carries, or a named column on the shapes themselves, which is what a parcel download carries.
• What it was read as: the format PadFlow decided the file actually is. It reads the bytes rather than the name, so a KMZ somebody renamed .zip is still read as a KMZ.
• The coordinate system, and where it came from. From the drawing means the engineer said so in the file. Inferred means PadFlow worked it out from your project's jurisdiction, which is a good guess and still a guess: check the lots land where you expect before relying on it.
• A verdict, in plain language.

The verdicts

Recommended. The linework closes and the drawing covers most of your register. This is the file you want.

One phase. It closes well but only covers part of the register. Almost always a single phase. Importing it places those lots and leaves the rest alone.

Usable with gaps. Some of the linework does not close, so some lots will be missing. You can import it now and replace it later with a better drawing.

No coordinate system. The shapes are readable but PadFlow cannot place them on the earth. Pick a zone and it reads the drawing again.

Not suitable. Either nothing matched a lot on this project, or too little of the linework closes to be worth importing. The confirm button is switched off, and the reason says so. Ask the engineer for the final plat drawing: it is the sheet with lot numbers on closed lot lines, and it is the one that works.

The two answers

Use as project map writes the boundary of every matched lot, in one go. Either all of them land or none do; there is no half-imported state to unpick. Lots the drawing did not place keep whatever they had.

Decline, draw instead marks the reading declined and takes you to the draw tool on the overview. Nothing changes.

You never need a drawing

The site map works with no CAD file at all. You can draw the project boundary and each phase limit by hand, and every lot stays on the board whatever the map shows. A drawing that fails, times out, or gets declined leaves the map exactly as it was.

A lot outline drawn by hand and one written by an import are the same thing to every other part of PadFlow. Nothing anywhere asks which produced a shape.

Coming back to it

Import as often as you like. A later drawing overwrites the lots it places, once you have confirmed it, and leaves the others alone. Earlier readings stay listed at the bottom of the page with what happened to each.