Guide • Topography
Topography to AutoCAD and Revit: contours for any site
To design on a sloping site you need contour lines with their levels. Atlasly exports contours from global terrain data as a DXF where every contour keeps its level, ready for AutoCAD, Civil 3D, Rhino or a Revit site surface.
Use this overview to plan your research. Verify current requirements and site-specific conditions against the relevant primary sources. Read our data sources, coverage and limits guide.
What you get
- Contour polylines on the C-TOPO-MAJOR and C-TOPO-MINOR layers of the DXF, in metres.
- Each contour's level is stored as its elevation, so it sits at the right height and shows in AutoCAD Properties.
- With Professional or one-off site credits, the OBJ export carries contours as 3D lines at their levels, alongside buildings.
- The contour interval comes from the source terrain data; you cannot choose it. There is no terrain surface mesh in the export.
Step 1: export the contours
- Open Export Map and search for the site.
- Draw an area a little larger than your site so the surface does not end at the boundary. Up to 1 km² is free.
- Keep the Contours layer on. Turn off other layers if you want a contours-only file.
- Choose DXF and download.
Step 2: AutoCAD and Civil 3D
- Open the DXF with File > Open and check UNITS is metres.
- Select a contour and look at Elevation in Properties to read its level.
- Use the 3D Orbit view to see the contours at their heights.
- In Civil 3D, create a TIN surface and add the contour polylines as contour data.
- Save as DWG if you need to share it in that format.
Step 3: Revit site surface
- Open a site plan view and use Insert > Link CAD with Import units set to Meter.
- Revit 2024 and later: Massing & Site > Toposolid > Create from Import > Select Import Instance, then pick the contour layers.
- Revit 2023 and earlier: Massing & Site > Toposurface > Create from Import > Select Import Instance.
- Check a few spot heights against a known level, then simplify the surface if it is heavy.
- Menu names vary by version. If the surface comes in flat, check that the contour layers you picked are the C-TOPO layers.
Rhino and SketchUp
- Rhino: import the DXF in metres. Use Patch with the contour curves to make a terrain surface.
- SketchUp Pro: import the DXF, then use the Sandbox tools (From Contours) to make a terrain mesh.
How accurate is it?
The contours are drawn from global terrain data, not a site survey. Their levels have an unrecorded local datum and the terrain source has a limited resolution, so small changes in level, retaining walls and recent earthworks will not show. Use them for early design and studio work. Commission a topographic survey before detailed design, planning drawings or construction.
Questions
Can I download topography as DWG for free?
You can download contours as DXF for free up to 1 km² and save them as DWG in AutoCAD or with the free ODA File Converter. Atlasly does not export DWG itself.
Can I choose the contour interval?
No. The interval comes from the terrain source. If you need tighter contours, use a survey or a local terrain dataset.
Can I make a Revit toposurface from the file?
Yes. Link the DXF in metres and use Create from Import with the contour layers. In Revit 2024 and later this is under Toposolid; in earlier versions under Toposurface.
Is this good enough for a planning application?
No. It is suitable for early design and student work. Planning and construction drawings need a measured topographic survey.
Download contours for your site
Draw the area, keep the Contours layer and download a DXF with levels. Free up to 1 km².
Open Export MapReview current plans and usage and source coverage for your project.