Ok I know most of the Documentation covers how to make a basic room this is just another to do it and a way to make you aware of what I think is the most valuable tool LithTech has to offer.

First make a brush

Now make sure your editor is in Selection-Mode

Make sure your brush is selected

Now place your curser in 32 units in from the edge of your brush and press V on you
Keyboard; now drag the white line in a straight line across your brush. Note it does not need to go right across as the engine assumes this line goes on for infinite along the 2 axis.
So in the screen shot below it will cut along the direction shown by the line and towards and away from you (if you get what I mean). This is the overhead view so the brush will be cut North/South as defined by the line and Vertical Axis defined by the view port you chosen

Now press V again this sets the second point and thus direction of the line to cut now press enter this will cut your selected brush

Now do the other sides using the same process.
Note when you cut a brush both parts will be selected after the cut is made.

Once four sides are made select them size them up to height you want then clone the floor for your roof. This is shown how to be done in the GO-Edit Documentation.

Barkey

Download this tutorial