Getting cadastre and lot boundaries into Civil 3D and QGIS: DXF, Shapefile and GeoPackage

You've got a new site and the clock's already running. Before you can set out anything, you need the lot boundaries in your CAD or GIS package, sitting in the right spot, on the right coordinate system, with the parcel geometry you can snap to. Sounds simple. In practice, getting clean cadastre out of the state portals and into Civil 3D or QGIS is one of those jobs that eats an afternoon if you're not set up for it.

This is a walk through how cadastral data works in Queensland, New South Wales and Victoria, what format you want depending on your workflow, and the small things that trip people up when the boundaries land in the wrong place.

What "cadastre" gives you (and what it doesn't)

Cadastre is the digital record of property boundaries - lots, plans, road reserves and the parcel identifiers that tie back to the title. Each state maintains its own digital cadastral database, and its currency and positional quality reflect the source mapping and survey history behind it.

A few honest things to know up front:

• It's not survey-accurate. The DCDB is a mapping-grade representation. It's excellent for desktop set-up, orientation and area checks, but it is not a substitute for a boundary survey. Corner positions can be out by a metre or more, and the gap widens in older or rural plans. Treat it as "where the lot is," not "exactly where the peg is."
• It carries useful attributes. Lot on plan (e.g. Lot 5 on RP123456), parcel type, and often the area. That lets you label parcels automatically instead of typing them in.
• It stitches to everything else. Once your cadastre is in the right coordinate system, contours, aerials and overlays line up on top of it. That's the whole point of doing the set-up carefully once.

Pick your format based on where it's going

The format you export matters more than people expect, because CAD and GIS want different things.

DXF - for Civil 3D, AutoCAD, BricsCAD. Boundaries come in as polylines, usually on a layer you can style. This is the one you want if the cadastre is going straight into a design set. The catch: DXF has no idea what a coordinate system is. It's just numbers in space. So the file has to be exported already projected into the right map grid, or your lot will land in the ocean. More on that below.

Shapefile - the GIS workhorse. Still the most widely accepted vector format across QGIS and ArcGIS. It keeps attributes (lot, plan, area) and carries a coordinate system definition in the .prj file. The downsides are old ones: field names truncate to ten characters, and a "shapefile" is really four-plus files that must travel together.

GeoPackage - the modern default for GIS. A single .gpkg file, no field-name limits, multiple layers in one container, and it just works in QGIS and recent ArcGIS. If you're staying in GIS, prefer this over Shapefile.

KMZ - for quick visual checks. Great for dropping boundaries into Google Earth to eyeball a site or share with someone who doesn't run CAD. Not a design format - it's in geographic (lat/long) coordinates, so don't set out from it.

The step that ruins the afternoon: coordinate systems

Most cadastre grief comes down to projection. QLD, NSW and Victorian site data should be working in GDA2020 MGA - zone 54, 55 or 56 depending on where the site sits - with heights in AHD. The east coast is mostly zone 56, inland QLD and NSW and central Victoria including Melbourne are zone 55, and western Victoria and far western NSW fall in zone 54. If your cadastre is in one datum and your survey pickup is in another, boundaries and detail won't overlap, and the offset can look convincingly small until you scale in.

A few practical rules:

• Export DXF projected into the correct MGA zone. DXF stores no datum, so whatever grid you export from is what you're stuck with.
• For Shapefile and GeoPackage, confirm the .prj/embedded CRS reads GDA2020 MGA and not GDA94 or WGS84.
• If your data shows up shifted by around a metre, you're almost certainly mixing GDA94 and GDA2020. It's a known ~1.8 m difference and it's the classic cause.

If any of that is fuzzy, it's worth getting the fundamentals straight in Getting the coordinate system right: MGA2020, GDA94 and AHD for QLD, NSW and Victorian site data before you import anything.

A clean workflow for early set-up

Here's the order that saves the most rework:

1. Confirm the MGA zone for your site (54, 55 or 56) and set your CAD/GIS project to GDA2020 MGA that zone, AHD for height. The export app suggests the zone from the site longitude, so you can take its default or override it.
2. Bring in cadastre first. It's your spatial anchor - the thing you check the aerial and the contours against.
3. Drape contours or the DEM on top. If you're deciding how tight to make them, Choosing the right contour interval is worth a look.
4. Sanity-check the overlap. Does the boundary sit sensibly around the aerial rooftop and driveway? A rough match is expected; a metre-plus consistent offset means a datum problem.
5. Label from attributes, not by hand - lot on plan and area straight from the data.

Done in that order, your base is ready for a desktop review or a first design pass in minutes, not hours.

Cadastre, project lot and easements in the current export

LayeredGeo currently offers property boundaries, surrounding roads and registered easement mapping for supported QLD, NSW and Victorian sites. These are separate selectable datasets, so you can take the cadastre alone or package it with terrain, planning and site-context layers. Compatible vector outputs are DXF, Shapefile, GeoPackage and KMZ.

The current sample ZIP contains 71 cadastral features, the selected project lot and two mapped easement features for its Queensland site. The GeoPackage keeps them as separate named layers; the DXF, Shapefile and KMZ folders show the corresponding handoff formats. This mapping is useful for orientation and early review, but the title and registered survey plan remain the authoritative sources for legal interests and boundary position.

Common questions

Can I use DCDB cadastre to set out a fence or building? No. It's mapping-grade and can be out by a metre or more, especially in older plans. Use it for site orientation, area estimates and desktop design. For anything built on the boundary, you need a registered boundary survey.

Which format should I export for Civil 3D versus QGIS? DXF for Civil 3D and AutoCAD, projected into the correct MGA zone so it lands in the right place. For QGIS or ArcGIS, GeoPackage is the cleanest choice; Shapefile still works if a client or tool insists on it.

Why do my lot boundaries not line up with the aerial or my survey? Usually a coordinate-system mismatch - most often GDA94 versus GDA2020 (about 1.8 m apart), or the wrong MGA zone. Confirm everything is in GDA2020 MGA for the correct zone and the offset should disappear.

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Want the boundaries, easements and terrain for a site without hunting through separate portals? Check the datasets for your address, see the current catalogue, or inspect the sample export.

LayeredGeo clips current QLD, NSW and Victorian site data into supported GIS and CAD outputs. Digital cadastre and easement mapping do not replace title documents or a boundary survey.

About this article. Published by LayeredGeo. It is general information about how property and ground conditions are assessed in Australia, not engineering, planning, legal or financial advice, and it is not specific to any property. Check anything that matters against the source dataset or a suitably qualified professional before you rely on it. If you spot something wrong, tell us at hello@layeredgeo.com.au and we will fix it.

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