I am in process of building bench work for a layout whose ambition far exceeds my experience. I am planning a two level layout at 14 inches and 36 inches (give or take) off the floor. I wanted to have the upper level capable of running any modern scale engines or cars. I planned a minimum diameter of 72 inches for the upper level with O-84 wherever possible. The lower level has some O-54. The two levels are connected by a double track line in essence creating a very long oval that folds over itself. Each level has crossovers allowing for running trains on independent loops without traversing from one level to the other. There is a 2.5% grade max between levels.
The upper right hand corner of the upper level needs to be fleshed out with freight service vs. second passenger terminal, vs. smallish roundhouse (debating if a 24" turntable is too small as it coudl just barely fit a scale hudson)
I have attached the SCARM file I am working on.
The green boxes are potential pool and ping pong tables and the grey boxes are walls that I do not want/ can not cut holes through.