@KVogler - Yeah - the terrible aspect of modo is the lack of good literature - and the stuff that is even half decent can cost some serious money to get access to. I will write a tutorial for this type of modeling as soon as I learn the rest of the process - I have absolutely no idea how I am going to even go about texturing this at all. I don’t even know if that is done from within another piece of software, or in unreal.
One thing I will definitely say I have learned from this model - is that I think there is something to be said for building up the ways first, floor by floor - that way it would be easy to have things like terraces added between floors without too many complications later on.
Extrude is the bread and butter of the model - along with the x-y-z position grabber, for things like adding angles.
Oh, and I think for horizontal extrusions (out the side, etc) it might be best to add them in after the building structure is complete - Not sure - still learning… when I know about what I am doing, I will likely write a document on it for everyone.