Create a 3D Site Plan Using CADMapper and AutoCAD

By Jon Henning •  Updated: 08/31/19 •  7 min read

CADMapper is a website that can save architects, designers, and planners tons of time by automatically generating 3-Dimensional information for over 200 cities around the world. CADMapper generates 3D models that can be used with AutoCAD, Sketchup, Rhino, and Illustrator. To generate information for topography, buildings, and streets, CADMapper pulls data from OpenStreetMap.

Need to quickly Create a 3D Site Plan Using CADMapper and AutoCAD?

I’ll walk you through exactly how to do that!

Before we jump in, please note that The intention of this tutorial is to use CADMapper to create a basis for architectural schematic designs. Site information should be field-verified by professionals in surveying, civil engineering, etc. to ensure accuracy.

Setting up a 3D site in CADMapper

Step 1: Find your site – Start with Google Maps.

Create a 3D Site Plan Using CADMapper and AutoCAD

I like to start by finding my site in Google Maps. Oftentimes, there is little information given that specifies coordinates or a physical address of a site. Searching for the site in Google Maps gives me a better understanding of what my site looks like from an aerial perspective.

Once you find your site in Google Maps, head over to and type in the approximate address – or two intersecting streets.

CADMapper only provides vector line information, so it might be cumbersome to try to search for your site starting in CADMapper. Look between Google Maps and CADMapper to hone in on your site, and create a box in CADMapper that captures the information you need from your site. CADMapper is free, but up to 1km of information.

Always try to capture more information than you think you need. You never know when you might need the information in the future. It’s better to have it and not need it, than to need it and not have it – I’ve had to stitch multiple CADMapper files together before because I left out some important information when I created my initial file, and it’s a real pain to go through that process.


Step 2: Turn on 3D Buildings

Create a 3D Site Plan Using CADMapper and AutoCAD

If you want building height information, check the box for 3D Buildings. If building information is available (which it often is in large cities), CADMapper will create mesh geometry of buildings in the CAD file. You can specify “False Height Data”, in which CADMapper will generate buildings without height information to a value that you specify. Not a necessary step, but it can you save drawing time.

Step 3: Select 3D Topography, topography contours spaced at 4 meters.

It’s good practice to just collect as much information as we can get, early in a project. The lowest spacing that CADMapper will generate for contour lines is 4 meters, which should be plenty of information to get you started in your design.

Step 4: Road Geometry, Select “Outlines”

Create a 3D Site Plan Using CADMapper and AutoCAD

CADMapper provides options for generating road graphics. Roads can be depicted as single center-lines, outlines, or mesh surfaces. If you intend on using this site file for fabrication, such as 3D printing or laser-cutting, I would suggest choosing an option that best suits your needs. For this tutorial, selecting “Outlines” will provide graphic separation between types of roads, and allow easy scaling of the drawing in AutoCAD. Additionally, “Outlines” is a good option to choose for laser-cut site models.

Change the road dimensions to specific dimensions: I recommend the following:

Highways: 10 Meters
Major Roads: 8 Meters
Minor Roads: 6 Meters
Paths: 4 Meters

Step 5: Generate the CADMapper File

Create a 3D Site Plan Using CADMapper and AutoCAD

If everything is set to your liking, click on “Create File”. It will take a moment to generate the file.

Once the file is generated, you can examine the map in 3 views:

3D Axonometric View
2D Plan View

At this point, select download. The file will download as a single .zip, containing one .dxf file that you can open with AutoCAD.

Converting Units – Metric to Imperial

By default, CADMapper exports units in meters. For our purposes, we need to convert meters to feet.’

Step 1: In the “Units” Menu, Change ‘Decimal’ to ‘Architectural’

Type in command, “UN” to open the Units menu. Change ‘Decimal’ to ‘Architectural’, and ‘Millimeters’ to ‘Inches’, respectively.

CADMapper for Architects

Note that simply changing the units will not change the scale the drawing.

For example, 2 meters will be converted to 2 feet, which is incorrect.

So, we’ll need to scale the drawing after changing the units from metric to imperial.

Step 2: Verify the Distance of a Road

Use the command “DIST” to measure the distance of one of the roads generated by the CADMapper file. It should read as one of the measurements that was specified on the CADMapper website. For this example, the road is 6 meters.

How to use CADMapper

Step 3: Scale the Drawing

If the road distance is 6 meters, it will need to be scaled to 19.685 feet (because 1 meter = 3.28084 feet) after changing the Units from metric to imperial.

Draw a polyline (command “PL”) off to the side of your drawing in model space somewhere. Below that 6 meter line, draw a line of distance, 19.685.

Use command “AL” for ‘Align’, and select EVERYTHING in model space. Deselect the (19.685) line. We want to scale everything in the drawing except that line.

Select the first point of the (6 units) line, and the first point of the (19.685 units) line. Then, select the second point of the (6 units) line, and the second point of the (19.685 units) line.

CADMapper and Architecture

When prompted to ‘Scale’, select YES.

If done correctly, all of the elements in the drawing will have scaled with the (6 units) line, which now matches the distance of 19.685. So now, when the Units are set to “Architectural” and “Inches”, all of the roads should read as the equivalent imperial measurement.

External References: Separating Layers into Drawings

Layers vs. external references for architecture drawings

CADMapper conveniently sorts drawings elements into separate layers. This is useful in terms of organization, however, we should set up our drawings in a way that allows multiple people to work on them. This may not be necessary for your particular project, but it’s good practice to learn the conventions of creating external references to keep file systems organized, and to allow the potential for multiple people to work on a single project.

Streamlined file systems = saved time on drafting work. And saving drafting time will open up time for more important stuff, like designing!

Here’s how to quickly create external references from layers:

Step 1: Open the Layer Menu

Type “LA” to open the Layer Menu. Freeze all layers, then unfreeze the first layer that you want to convert into an external reference. In this case, we’ll start the the layer called “buildings”.

Next, type “Select” and “All” to select everything on that layer.

“Copy Base” with, CRTL+SHIFT+C, then specify the origin point as 0,0,0 (x,y,z, respectively).

This is important, because copying the information with the origin point will allow you to bring all of the drawings into the new “Master Drawing” at the same point. This will ensure that the drawings are lined up correctly, maintaining accuracy in the information.

Step 2: Create the “Master Drawing”

Open a new drawing. This will become the “Master Drawing”, which will hold all of the xrefs that we will be creating for each layer. The “Master Drawing” will look exactly like the original file containing all of the individual layer information. The benefit of setting up a master drawing this way, is that multiple people can work on individual files within one project.

For example, one person can work on the “Buildings” layer. Another person can work on the “Roads” layer, and so on.

This is not only convenient for group drafting projects, but it will help you build a consistent file system that can be applied to a number of different programs outside of AutoCAD. It’s just a system of file linkage, and these types of systems offer the most flexibility for organization, and drafting workflows.

One final note: the “Master Drawing” should serve as a file for reference, and should not be drawn on or referenced to other drawings. Changes made on all of the other external references will reflect on the Master Drawing, however, changes made on the Master Drawing will not reflect on the linked external references. It’s a one-way street, and maintaining this system will ensure that your project is clean and organized.

Continue this tutorial series, here:

👉 Next Tutorial, #2: How to Use CADMapper to Create Revit Topography

Jon Henning

Hi, I'm Jon. I write about emerging technology in architecture, engineering and design, and I want to help you push boundaries with the latest tech trends in the AEC industry.

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