I’ve always wondered about using old shipping containers as shaping/glassing/airbrush bays. Article in WSJ this morning indicates that a used container 20-40 feet long will cost between $1000-to-$1300 dollars; I would assume that includes delivery. Plunk one or more of these bad boys down and run a 20A line to each plus some metal cutting modifications and I think you’d be in business in short order. A quick search shows that internal height is between 7’9" and 8’9" feet and internal width is pretty standard at 7’7" (a little tight for SUPs). A 40’ length would easily hold two bays. A simple 20’ would be good for a roomy single + storage. Food for thought.
…not enough space to “see” a long board; cannot put a long board standing up right; claustrophobic room; and you ears SHOULD have ALWAYS protection; is a resonator!
If you have no problems with the houses besides, do it in steel framing with the walls and ceiling in iso panels.