Steel shop question

My neighbors example. Shortly after they handed him the door key he realized it was nothing like what he was accustom to. Cant just drive a nail wherever you want to hang a clock on the wall. Anyway, a thick hedge around the outside was a good start.
A lot of time and labor went into the inside. 2X2, 2X3, and 2X4 notching and framing, hard styrofoam sheeting, 1/8 paneling. White paint reduced the amount of electric lighting needed. The dead air space between the insulation and sheet metal is a big part of it. ( I do question how much condensation is going on in there. ) A small window unit keeps it like a ice chest in summer. A vent free propane cast iron stove keeps it toasty in winter. Wiring, plumbing, cabinet hanging, whatever, is much more like conventional stick built.
I should add that at our age there isn't a lot of real working in our garages. More like man caves.