CADMapper: Download Site Context and Check It Before Design

CAD Mapper (styled CADMAPPER) is a web tool that turns public map data into layered CAD files of any location. You can download custom areas up to 1 km² free with a free account. Whole-city road networks for 241 metro areas are free with no account at all. Areas up to 100 km² cost a small fee, with a discount for academic email addresses. Files arrive as a ZIP, in metres, with the model positioned at the origin.

This guide is for architecture students and practitioners who need a site base drawing quickly. It sets out what each tier actually contains and which export format suits your software. It also explains what the Open Database Licence asks of you when you publish a drawing, and the four quirks that make a perfectly good file look broken.

Verification note: tiers, the free city list, licence terms and the units and origin guidance were re-checked against cadmapper.com, its help and FAQ page and its terms of use on 20 October 2026. Where a software-specific note relies on CADMapper’s help page as Arch2O last checked it in August 2026, the format table says so. Arch2O did not run its own timed export for this update. CADMapper changes its tiers from time to time, and the live site always has the final word.

What is CAD Mapper?

CAD Mapper is a browser-based service that converts public geographic data into ready-to-use CAD files. You define an area on a map and choose a format. It then returns a layered drawing of roads, buildings and water, plus building heights and topography in many locations. CADMapper names OpenStreetMap, NASA and USGS as its public data sources. It does not model or draft anything itself. The file it produces is a context layer for whatever architectural design software you already use.

According to its terms of use, the website is operated by Protomaps LLC, trading as Cadmapper. Downloaded CAD files are distributed under the Open Database License (ODbL), with the data credited “© OpenStreetMap contributors”.

The practical value is simple. Drawing a site base by hand, or tracing it from an aerial image, takes hours and adds nothing to a design. CAD Mapper cuts that down to minutes. You still need to check the drawing, but you no longer need to trace it.

The drawing itself belongs to an old tradition. Giambattista Nolli’s 1748 map of Rome is the classic figure-ground plan: built mass in dark tone, streets and public space left open. A CAD Mapper file gives you the raw geometry for exactly this kind of context drawing in minutes.

Is it legitimate? Yes: CADMapper is an established service operated by Protomaps LLC, with published terms of use and a public help page. Its files are built from openly licensed sources and carry a clear licence (ODbL), in standard CAD formats. How reliable a file is depends on the underlying map data for that place, not on the tool itself.

Is CAD Mapper free? The limits, stated plainly

Yes, through two separate free routes. A third, larger option is paid. The CADMapper homepage squeezes all of this into three tiles, which is where most of the confusion starts.

The distinction that matters: the free whole-city downloads are 2D road networks and water only. If you need buildings, heights or topography, you have to use the custom-area route, and that is where the 1 km² ceiling applies.

For scale, 1 km² is 100 hectares (about 247 acres), a square 1,000 m (3,281 ft) on each side. That comfortably covers a single plot and several surrounding blocks of context. It is usually too small for a masterplan or an urban study, so you will either pay for a larger area or combine sources (see below). CADMapper’s homepage describes the premium tier only as “a small fee”, and Arch2O could not confirm a current price from a public CADMapper page, so none is quoted here.

Where the free whole-city files are available

The homepage says there are “over 200” metro road networks. Counting the list on CADMapper’s Free City Files section on 20 October 2026 gives 241, split into seven regions of CADMapper’s own choosing. The list includes Amsterdam, Atlanta, Bangkok, Cairo, London, Mumbai, São Paulo, Sydney and Tokyo. Each file is a large, simplified two-dimensional DXF containing three levels of roads as polylines, plus bodies of water.

Building heights and terrain are available in many locations, but only through the custom-area download, not in the free whole-city files. Whether they are included depends on the coverage of the underlying data for that location.

Which export format should you choose?

The right format depends on the software you are importing into. Choosing badly is the most common reason people decide the geometry is “bad”. Usually the geometry is fine and simply in the wrong container. The CADMapper homepage lists AutoCAD, SketchUp 8+, Rhinoceros 5+ and Adobe Illustrator as target programs. Its help page adds workflows for Revit, Archicad and Vectorworks.

There is one discrepancy you should know about. The homepage lists SketchUp 8 and later, but CADMapper’s help page (as checked in August 2026) said SKP files are saved in the SketchUp 2015 format. If an older copy of SketchUp refuses a file, that is the likely reason. Updating SketchUp or importing a different format avoids the problem. If you are taking the site into Revit, you will soon need free Revit families to populate the model around it.

For SketchUp, use the native SKP export. For Revit, CADMapper’s help page describes bringing in a DXF or Rhino 3DM file. Set the units to metres in both programs before importing.

How to get a site CAD file in about five minutes

CADMapper says it produces files “within minutes”. Most of your own time goes on defining the area and opening the file correctly. The steps below follow CADMapper’s own instructions. Arch2O has not timed an export for this update.

1. Open the map tool. Go to cadmapper.com and choose “Try it now”. Custom areas require a free account, so sign up or log in.
2. Define your area. Keep it at or under 1 km² to stay in the free tier.
3. Choose your format from the table above, based on where the file is going. Building heights and topography are not available everywhere, so expect fewer layers in less-mapped places.
4. Download and unzip. The file arrives as a ZIP. Extract it before opening.
5. Open or import with units set to metres. All CADMapper models use metres. If your template is in millimetres or feet, the site will come in at the wrong scale.
6. Zoom to the origin. The model sits at 0,0,0, so zoom to extents if the screen looks empty.

Four quirks that make people think the file is broken

None of these is a fault in the data. CADMapper documents all four on its help page, and each takes moments to fix. Together they account for most “CAD Mapper doesn’t work” complaints.

1. You open the file and see nothing

The model is located at the origin (0,0,0), and your view is probably pointing somewhere else. Zoom to extents. In AutoCAD, CADMapper suggests clicking [Top][Top] at the top left of the viewport to recentre the view. Very large files can also take a while to draw, so give them a moment before you assume the import failed.

2. Everything is the wrong size

All model units are metres. Select Meters when opening or importing, and do not let the software assume millimetres. A millimetre template makes the whole site 1,000 times too small.

3. AutoCAD throws an error when you double-click the DXF

Do not open the DXF by double-clicking it in your file browser. Start AutoCAD first, then use Open from the top-left menu. CADMapper’s help page describes this as the way to avoid the error. It is a file-opening issue, not a problem with the file.

4. Nothing opens at all

The download is a ZIP archive. Extract the CAD file first. Several programs, including Archicad’s Place External Drawing route, expect the unzipped file.

Can you use CAD Mapper files commercially?

Yes, on the licence’s terms. CADMapper’s terms of use (last updated May 2017) allow commercial use of the site. They say data under the ODbL may be used commercially as long as you comply with its attribution and share-alike conditions. In practice, any drawing, board or report that shows CADMapper geometry needs an OpenStreetMap credit.

Licence and attribution for OSM-derived data

The OpenStreetMap copyright page (checked 20 October 2026) says that wherever you use OpenStreetMap data, you must do two things:

• Credit OpenStreetMap by displaying its attribution notice: “© OpenStreetMap contributors”.
• Make clear that the data is available under the Open Database License. Online, you can link to openstreetmap.org/copyright. In print, where links are impossible, include the full URL.

For a competition board, planning submission or printed portfolio sheet, a line in the title block or drawing notes covers both requirements. For example: “Base map data © OpenStreetMap contributors, available under the Open Database License: openstreetmap.org/copyright. Site file generated with CADMapper.” The OpenStreetMap Foundation’s attribution guidelines explain how placement rules differ for browsable maps, printed maps and static images.

Share-alike is the part that needs care. OpenStreetMap’s summary says that if you alter or build upon the data, you may distribute the result only under the same licence. The ODbL treats a database differently from a drawing or image produced from it. If your deliverable is itself a dataset, read the full ODbL legal code before you distribute it. Examples include a cleaned GIS layer handed to a client or a 3D city model published for reuse. This section explains the licence. It is not legal advice.

Terrain is a separate question. CADMapper names NASA and USGS as sources but does not say on its homepage which terrain datasets it uses. If your deliverable depends on the topography, ask CADMapper which dataset applies before relying on its terms.

What to do when you hit the 1 km² free limit

The 1 km² ceiling is where most people start looking elsewhere. Here are the options, roughly from least to most effort:

• Combine the two free routes. Download the area that really needs buildings and terrain as a free custom file of 1 km² or less. Then take the wider context from the free whole-city road network if your city is one of the 241 listed.
• Pay for a premium file covering up to 100 km² (38.6 sq mi). If you have an academic email address, register with it first to get the discount.
• Build it yourself in QGIS from OpenStreetMap data. This gives you free, unlimited extents and full control over layers. The catch is a real learning curve and a manual DXF export.
• Use OpenStreetMap’s own export. It gives you raw .osm data rather than CAD geometry, so you need to convert it before drawing on it.
• Check national LiDAR, open-data and municipal GIS portals. Where they exist, these are the best sources for accurate terrain, and the only ones for legal plot boundaries and zoning. Coverage and formats vary by country and city.

Which alternative is better depends on the job. For larger areas at no cost, QGIS with OpenStreetMap data gives you more control in exchange for more work. For accurate terrain or legal boundaries, national LiDAR and municipal GIS portals are more authoritative. For a quick, layered context file of one site, CADMapper’s free 1 km² tier remains hard to beat on speed.

How accurate is CAD Mapper, and when should you not rely on it?

CAD Mapper is only as complete as its source data in a given place. OpenStreetMap is built by volunteer contributors, so mapping density varies from one city, and even one district, to the next. CADMapper itself says building heights and topography are available “in many locations”, not everywhere. Recent buildings may be missing, and heights may be absent or approximate.

Terrain is a separate layer from the buildings. CADMapper names NASA and USGS among its data sources; global elevation datasets such as NASA’s Shuttle Radar Topography Mission (SRTM) describe the shape of the ground well enough for massing and site studies, but not with the precision of a measured survey.

That makes it excellent for what most people use it for: context massing, site studies, competition boards, early design work and diagrams. It is not a survey. Do not use it for setting out, boundary determination or anything with legal or construction consequences. Those need a measured survey and the official cadastral record for the jurisdiction concerned.

The sensible workflow is to treat the CAD Mapper file as your context layer and overlay verified survey data for the plot itself. That split also matches how a site study should be organised. Our guide to site analysis covers what to record, and in what order, once the base drawing exists.

Before using downloaded geometry in a design submission

Treat an exported site model as context, not a survey. Open the file in a blank project, check its units and compare a known distance with a reliable reference. Record the download date, data sources, missing buildings and assumed heights. Keep the original geometry on a separate layer from your design. If a roofline, boundary or ground level controls a planning or access decision, replace the assumption with surveyed or authority-confirmed information. A polished model can still contain gaps: identify those gaps in the drawing notes rather than hiding them behind detailed materials.

Decision summary and next step

Use CAD Mapper when you need a quick, layered context drawing of a single site. Stay within 1 km², pick the format that matches your software, open it in metres and zoom to the origin. Add the OpenStreetMap credit to anything you publish. Pay or switch tools only when the study area outgrows the free tier. Never use the file in place of a survey. For construction details rather than site geometry, see our collection of free stair detail CAD files and layouts.

Sources and further reading

• CADMAPPER homepage: tiers, area limits, academic discount, data sources and the free city list (accessed 20 October 2026).
• CADMAPPER help and FAQ: units, origin and import steps (accessed 20 October 2026; software-specific notes from August 2026 check).
• CADMAPPER terms of use: operator, data licence and commercial use (accessed 20 October 2026).
• OpenStreetMap copyright and licence: ODbL summary and attribution requirements (accessed 20 October 2026).
• OpenStreetMap Foundation attribution guidelines: placement of credits by medium.