Something else to consider is material handling and tool/accessory storage. You need to be able to load materials onto the machine and secure it to the table at least around the perimeter of the piece. You also need a place for the computer, monitor, and all the other peripherals - plus all of your tools, collets, fixtures, clamps… You get the idea. Add in a dust collector and the duct work that requires, and you can see where this is going. And you still need to be able to load and mount the material after you’ve shoehorned all of that other stuff into the shop. I only have a 4X4 machine in a 12 x 16 foot shed, and things get very tight when I need to mount large pieces.