Frequently asked questions

Yes. LiDAR measures ground elevation from aircraft, and once the points are filtered to bare earth, contour lines can be generated at intervals down to 1 foot where the data quality allows. ContourLabs does that processing for you: we find the LiDAR for your site, filter it to ground, build the surface, and deliver labeled contours as a CAD-ready DWG/DXF and a print-ready PDF.

ContourLabs uses public airborne LiDAR, primarily from the USGS 3D Elevation Program (3DEP), plus state and county collections when they're newer or higher quality for your site. Every map includes a Data Quality Report naming the exact dataset, its collection year, and its quality level, so you always know what your contours are built on.

USGS publishes 3DEP LiDAR for free through The National Map Downloader and the USGS LidarExplorer, and OpenTopography hosts many of the same datasets. The data downloads as raw LAS/LAZ point cloud tiles, often several gigabytes per site, and needs specialized mapping software to filter to ground, build a surface, and generate contours. If you'd rather skip that step, send ContourLabs the address and we'll deliver the finished contours.

Probably. USGS reports baseline 3DEP elevation data available or in progress for about 99% of the US, although quality and collection year vary by location. Enter your address in the free coverage checker to see what exists for your site. If the data isn't good enough, we tell you before you pay.

Standard USGS 3DEP LiDAR (Quality Level 2) is specified at 10 cm RMSEz vertical accuracy in open terrain, about 4 inches, or roughly 20 cm (7.7 inches) at 95% confidence. Accuracy is lower under dense vegetation, and the data won't show grading or construction done after it was collected. Every ContourLabs map includes a Data Quality Report with the quality level and collection year for your site.

No. LiDAR contours are not a certified or stamped topographic survey, and ContourLabs maps aren't a legal boundary determination. They are accurate enough for feasibility, bidding, concept design, and early site planning. Final design, construction staking, boundary work, and permit-grade elevations still need a licensed land surveyor.

ContourLabs delivers contours down to 1-foot intervals where the source data supports it. That's typical for Quality Level 2 LiDAR or better in open terrain. The finest honest interval depends on your site's data quality and ground cover, so we check it before you order. Every file includes major (index) and minor (intermediate) contours on separate layers.

Often, yes. Some LiDAR pulses pass through gaps in the canopy and reach the ground, which is why LiDAR maps forested terrain better than aerial photos. Under dense evergreen cover, fewer pulses reach the ground and accuracy drops; USGS allows up to 30 cm at the 95th percentile in vegetated areas for Quality Level 2. Your Data Quality Report flags this for your site.

It depends on the location. Most 3DEP collections are less than about 8 years old, but some areas are older. Collection date matters because new roads, grading, and buildings won't appear if they were built after the flight. ContourLabs lists the collection year for every map and uses the newest suitable dataset available for your site.

ContourLabs delivers DWG and DXF files that open in AutoCAD, Civil 3D, MicroStation, Revit, Rhino, SketchUp Pro, and other CAD or BIM software that imports DWG or DXF. You also get a print-ready PDF for client meetings and markup.

Order them as a DWG. A ContourLabs file opens directly in AutoCAD, or you can XREF it into your base drawing. Major contours, minor contours, and the parcel boundary are on separate named layers with elevation labels. In Civil 3D, you can add the contours to a TIN surface for grading, profiles, and earthwork.

Every ContourLabs map includes a layered DWG/DXF (major contours, minor contours, parcel boundary, and elevation labels on named layers), a print-ready PDF, and a Data Quality Report with the source dataset, collection year, and quality level. Parcel boundaries and building footprints are included as site context where public data is available.

Yours. Tell us your state plane zone (or other projection) and vertical datum when you order, and ContourLabs delivers the files in that coordinate system. If you don't specify one, we use the standard state plane zone for your site and label it clearly in the file and the Data Quality Report.

Yes. Upload a KMZ, KML, or GeoJSON boundary, or send an address or parcel number and we'll use the parcel lines. You can also ask us to extend past the property line to capture uphill drainage or neighboring terrain. Pricing is based on the total mapped area.

Yes. Every ContourLabs map includes your parcel boundary at no extra cost, delivered on its own named layer in the DWG/DXF alongside your contours. Maps start at $30 for sites up to 1 acre.

ContourLabs pulls parcel boundaries from county assessor records through a nationwide parcel data service that covers most US counties. The lines are the same ownership boundaries the county uses for property tax records.

Assessor parcel lines are approximate. They're drawn for property tax purposes, not surveying, and can be off by several feet or more, especially in rural areas or where records are old. Use them for planning and early design, not for construction or legal boundaries.

Yes. Send ContourLabs an APN (assessor's parcel number), a street address, or coordinates. For large or unaddressed rural land, an APN is often the most reliable way to identify the exact parcel.

Yes. Upload your boundary as a DWG or KMZ file when you order, and ContourLabs will use it in place of, or alongside, the county parcel line.

The parcel boundary is on its own named layer in your DWG/DXF, separate from major contours, minor contours, and building footprints, and in the same coordinate system as the rest of the file. You can turn it on or off, or restyle it to your office standards.

No. A parcel boundary from county assessor records has no legal standing. Permits, fences, construction, title work, and property disputes need a boundary survey from a licensed land surveyor.

They're a free add-on. Check "Add building footprints" when you order, and they arrive on their own layer in the same DWG as your contours and parcel boundary, at no extra cost.

ContourLabs uses public building footprint data, which maps building outlines from aerial and satellite imagery using machine learning. We clip it to your project area and align it to the same coordinate system as your contours.

Accurate enough for context and early design, not survey-grade. Footprints trace the roofline, so eaves can make them slightly larger than the walls, and edges can be off by a few feet. Recent construction may be missing because imagery dates vary by location.

No. Footprints are 2D outlines on their own layer. You can extrude them to rough massing heights in your own software.

Yes. You get every mapped building inside your project area, so if your map extends past the property line, the neighbors' buildings are included.

Typical turnaround is 24 hours, and files are delivered to your inbox. Professional and Studio plan members get priority turnaround. If we find a data problem with your site, we tell you before you pay rather than delaying your order.

Pricing is based on property acreage. Maps start at $30 for properties up to 1 acre, $100 for 1–5 acres, $250 for 5–20 acres, $500 for 20–30 acres, and $750 for 30–100 acres. For properties over 100 acres, contact us for a custom quote. Firms that order several maps a month can join a membership starting at $425/month for a $500 monthly map allowance.

Then you don't pay. ContourLabs checks data coverage and quality for your site before you order. If the data is too old, too sparse, or missing, we tell you up front, and you can join a notification list for when new data is collected.