The bulkiest thing in my shop is a box (recent build) about 3x3x4 feet that my CNC mini-mill fits into. It needed an enclosure for noise and dust.
It's mostly a woodworking mill, but it's fairly versatile. I cut lots of PCBs with it, I can cut brass and aluminum parts if I'm careful with the settings, and I can cut steel (very slowly) if I write the G-code myself to do lots of pecking and short shallow cuts. It's also becoming more versatile the more I figure out how to do with it by swapping out the spindle. I adapted a reprap plastic extruder toolhead so I can use it as a 3-d printer, made a pick-and-place head using a couple of stepper motors I got out of a roomba for simple assembly, adapted a different extruder head to apply etching agents and flux for soldering, etc. I'm continuing to try to make the CNC usable for more and more stuff, with different toolheads.
The rest of the shop has a tabletop drill press, a tiny homemade press/injection molding setup made from a bottle jack (usually used with molds I cut in the mill), and a bunch of hand tools. Lots of toolboxes, lots of tiny parts bins.
The whole shop is about 160 sq. feet, with a 9 ft ceiling - tiny. Also, I have two standing constraints: all my tools, and everything I build or work on with them, have to fit through a standard 32" doorway, and have to be things I personally can carry up and down stairs. One foot of the height of my mill enclosure is a lid that comes off, and I don't think I could have owned a mill at all if I weren't a weight lifter. Even without the enclosure, it's a 200-pound tool.