Don't be embarrassed. There are two different 'CAD' coordinate/axes conventions. One grew from 2d the other reflects 3d more sensibly... The older way is indeed what you had wrongly assumed for SketchUp. Old way... X left/right on screen == 'Width' Y up/down on screen == 'Height' Z in/out of screen == 'Depth' SketchUp and several other newer 3d apps... With an 'Origin' at [0,0,0] defining the 'ground-plane' X left/right on a 'ground-plane' == Red, aka 'Length' Y in/out on a 'ground-plane' == Green, aka 'Depth' Z up/down from the 'ground-plane' == Blue, aka 'Height' Points, offsets etc are always defined as [X, Y, Z] values In fact for those of us using the Ruby API... the SUp 'bounding-box' convention is the awkwardly set up as the 'old-way' - which can be very confusing as bb.width/bb.height/bb.depth is actually bb.x_size/bb.y_size/bb.z_size, when intuitively we might assume the SUp convention of x/z/y The two coordinate/axes conventions lead to some anomalies when importing/exporting - where you might see 'Flip Y/Z Axes' options. This is there to convert one set of axes to another, otherwise an imported object might come in 'laid on its back' etc...

One of the first things you should do with SketchUp is pee in the corners. Make it your own. Create your own template. I always use a white background when drawing. I set up the style as shown in the screen shot for my default style and because I need to work in fractional inches, I set units that way. Then I saved a blank file as my default template. [image: 15589298213_f21aa143f8_z.jpg]

Let me reinforce what Dave has said: using inferencing effectively is one of the most valuable and essential SketchUp skills you can learn. You'd be surprised how many defective models get submitted for help when something won't work because elements of the drawing are subtly out of alignment. This problem is almost without exception the result of not using inference properly!