In this test I was going to try to use cuboids with positive and negative values to build a 3D floor plan of a simple 1 room building. I had no problem setting up the outer walls. But I started noticing some problems when I went to punch some holes in the wall for the door and 2 windows. It seems that if you place the door off center from the midpoint of the wall, that it won't punch a whole when using negative values. In this case, the walls are 20 units long and I wanted to punch the hole for the door 12 units from the far corner, but it would not punch through. But, if I placed the door 10 units from the far corner (i.e. centered in the middle of the wall), I had no problem punching the hole for the door. Since my windows are not in the center (as they are on either side of the door), they would not punch through. As the code is now, the 4 walls are drawn with a click on the green flag, and the doors and windows are (supposed to be) added if you press the space-bar. You'll see the placement of one of the windows, but just a "blip" where the other window is supposed to be. I believe the blip is probably the beetle "pointer" icon. There are 3 additional command blocks floating outside the actual program that correspond to blocks nearby in the program with the parameters set positive or set negative, so you can more easily change them. There maybe something I'm doing wrong, or maybe a bug in BeetleBlocks. Let me know either way. Here's a screen shot of my code: