Attached 2-car garage, w/a loft over the rear-half of the garage. The loft was a compromise, it doesn't have 'stand-up' height, but it provides me about 230 sq. ft. of floor space for storage and I have a 360-degree swiveling jib hoist w/a 120 V power up/down motor to lift the heavy things.
I don't have a 'permanent' air system yet. I have a 240 V Campbell-Hausfeld VT610401 30 gallon wheeled compressor 8 CFM @ 90 PSI and just to have an air source close-to the workbench but out of the way, I ran air hose from the niche for the compressor to over my workbench. That's where I mounted my air hose reel, on the front steel beam, which is 'sandwiched' with 2" X 8" through-bolted fir, of the loft structure. The steel horizontal beam is 4" X 8" X 1/2" which is 20 ft long, spanning from garage side wall to garage side wall. The beam is welded to flitch plates set-into steel-reinforced 8" X 24" concrete columns running from the foundation to the top tie-beam for the roof structure. There is a 2 ft X 4 ft footer enlargement below the 8" X 24" poured concrete columns into-which the flitch plates are set. The retractable air hose reel is lag-screwed into the 2 x 8 on the front of the 4 X 8 steel beam.
One day, I'll get-around to running a proper air supply rigid line, with a pitched run, drains and a dryer/cooler, but that won't be until I upgrade to a higher-capacity compressor. At-least I didn't use rigid PVC!
I also have a manual portable air hose reel if I needed to reach an additional distance.