I am digitizing the floorplans of various schools in our county. This is for the Fire Department so they want to be able to see where doors are within the building. The doors do not necessarily have to be indicated; a gap in the wall is sufficient.

It would be much more efficient for me to use the 90 degree tool and knock out these classrooms in full. Is there some sort of eraser feature that might split a line segment in two wherever it intersects? That way I could basically create a rectangle for the room and erase where the door might be to leave a gap.

Or are there any other tools that could make this process easier? I've got a few dozen schools to digitize, and by far the most time consuming process is creating small segments around the doors just to leave that gap.


  • 6
    Are you set on using ArcGIS for this task? I know many people use it for what would be considered non-geographic mapping, but IMO there are better tools suited to the job. E.g. AutoCAD, Google SketchUp. – Radar May 16 '13 at 21:10
  • 3
    Agreed, please don't hurt yourself using ArcMap for this :) – blah238 May 16 '13 at 21:15
  • As per your advice, I've grabbed SketchUp and am getting familiarized with it. My main question would be about getting the correct scale. My floorplan image was georeferenced within ArcMap. When I import that into SketchUp, does it retain the new scale? If I digitized the floorplan and exported into ArcMap, will the scale be correct? Would I be able to adjust? – Kyle Shepard May 17 '13 at 17:21

While I agree that there are much better tools to accomplish this task, I'll give it a go just for the sake of answering the question, as cumbersome as it may be. It is still going to take a good deal of manual effort, but at least you can knock out multiple doorways at once this way.

Basically, you can create point features wherever your doors are, buffer them to half of the average door width, and erase the buffered points from your classroom feature. Here's some pictures of a quick mock-up I ran:

Step 1: Create point features where doors are located

enter image description here

Step 2: Buffer point features to 1/2 the average width of doors (or if you need to be more precise for each door, add an attribute column that holds 1/2 door size and buffer using this column instead of a constant)

enter image description here

Step 3: Erase buffered point features from your classroom line features

enter image description here

Note: If your classroom features are actually polygons and not lines, you'll end up with something like this instead. Not very pretty:

enter image description here

While not ideal, this will get the job done. I would definitely look at the mentioned alternatives.

P.S. Hi Kyle.

  • 1
    +1 That's an excellent solution given the software limitations. – Radar May 16 '13 at 22:32
  • Many thanks Mister Michael. And here I thought you only knew DB's. For others who posted: unfortunately, I'm fairly limited to ArcGIS. I'm an intern and I don't have the software availability you might find in other places, although I might be able to get some open source CAD programs if such exist. – Kyle Shepard May 17 '13 at 14:38

Have a look at the functionality that the 'Overlay' toolbox within the Analysis toolset provides- There are some good options there that will allow you to keep the doors and buildings featureclasses separate and then run an overlay process at the end (such as an 'erase'). Doing it this way means that any errors (say in the placement of doors, or the size of door openings) can be fixed by re-running the overlay at the end to re-create the final feature class.

If you are using lines instead of polygons, then the 'Planarize' tool may do what you want- This will split all lines at any self-intersections.

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