Slab Edge but with a Void

1. Create the profile.  I used a hosted profile template, not sure if that was necessary.
2. From a good 3d view choose:
1. Structure
2. Component
3. Model in Place
4. Select Family Category "Floor"
3. Give the model a name, I think this will be different for every different location, so don't get too generic.
4. Select Void Forms
1. Void Sweep
5. Select Pick Path, and choose the slab edge that will define the void. (I assume you could select multiple edges if they are all the same? Not unless they are continuous.)
6. The edge should highlight and a ghosted "profile" will appear.  Make sure you can see these or you will have trouble placing the void profile.
7. Hit the checkmark once you have selected the slab edges you want to sweep.
8. On the Select Profile tab in the Profile: box, choose the correct profile of your void, an outline of the profile will appea, you may have to select Modify Sweep tab first.
9. Adjust the mirroring and / or offset dimensions until the profile appears at the correct location on the slab, you may have to select the profile outline.
10. Select Finish Edit mode.
11. CHOOSE Cut
1. Cut Geometry.
12. Select the slab, then select the "void profile", then Finish Model.