Deliverable · Civil 3D Surface Model

A Civil 3D-ready surface from public lidar, in minutes

Building an existing-ground surface from raw lidar normally means downloading tiles from a government portal, classifying and clipping the cloud, reprojecting it, and coaxing it into a TIN — hours of GIS work before design starts.

ToposNow does all of it in one step: the ground-classified (ASPRS Class 2) returns for your exact site are triangulated into a TIN surface and written as a DXF with the coordinate system embedded (GEODATA). Open it in Civil 3D or AutoCAD, and convert to a surface object — that’s it.

Draw your site — free reportDownload a real exampleFrom $65 + $0.10/acre

Step 1

Draw your site

Sketch the parcel on the map or import a KML boundary.

Step 2

Pick your coordinate system

Any EPSG — your State Plane zone, ftUS or metric, with vertical datum control and survey localization if you need it.

Step 3

Download the DXF

A ground TIN at your chosen resolution (15 ft default), generated in minutes.

Built for

  • Feasibility grading and concept design before survey budget exists
  • Existing-ground surfaces for drainage and earthwork studies
  • Checking a site remotely before quoting field work

Opens in: Autodesk Civil 3D, AutoCAD, BricsCAD.

Common questions

How do I import the DXF into Civil 3D?

Open the DXF directly — the coordinate system is embedded via GEODATA. Create a new TIN surface and add the drawing’s 3D faces as a definition, or paste the triangles into an existing surface. No transformation or scaling needed if you ordered your project’s coordinate system.

How accurate is a lidar-derived surface?

Modern USGS 3DEP collections state 10 cm RMSEz vertical accuracy on open terrain (QL1/QL2); older collections up to 20 cm. Your site’s free availability report quotes the exact figures for the collections covering it. It is not a survey and does not replace one where one is required.

What TIN resolution should I choose?

The default 15 ft grid spacing suits most site-design work. Finer spacing captures more micro-terrain at the cost of a heavier drawing; the configurator lets you choose per order.

Other deliverables

Contour Map (PDF) · Raw LAS · Elevation Model (GeoTIFF) · ENU Points (E, N, U) · Coverage by state

Source: USGS 3D Elevation Program (3DEP) lidar. Pricing shown as of 2026-07-10; the exact quote for your site is computed when you draw it. ToposNow deliverables are derived from published USGS lidar and are not a land survey.