We had something in the mid 70's similar in one guys backyard till we kinda got busted when I was 14 or 15.
Was pretty nice, insulated, space heater, electricity, bongs hidden a bit in the roof space area, was more a clubhouse I guess.
I have an uncle has a bar like that kinda, but it's built on the end of his boat dock on a lake in Michigan.
Several people in FL have little Tiki Bar things by the pool I guess, some actually pretty damned big.
Never bothered to build one out there myself.
My Florida room kinda looked along those ways at one time. ought to do something with it.
300 enclosed square feet by the pool not doing much atm.