Vectorworks has some really cool 3D tools, and it's tempting to always look at these…
Vectorworks Tip #185 – 3D Modelling – Add Solids
This is where you take two or more three-dimensional objects and you join them together. The strategy with 3D modelling is to break your object up into simple, manageable chunks, then use Add Solids to join them together. In this image you can see that I created several different colored objects. When added together, you get a single object.