Here in Southern California we're packed in like sardines with our zoning regs , land prices, and HOAs so I'm quite envious of all the pictures of brew sheds and basement builds. But seeing as how i can't move (would i want to? 70's-80's for the next week going into Jan) i had to come up with a brew rig that takes up as little space as possible. After much research and pondering i came up with a single tier that stores vertically with the keggles housed within the frame.
The frame is mostly 1" angle iron, with 1" flat bar providing some vertical support and/or containment for kegs while in storage. The steel is painted black with BBQ paint. Steel angle is cheap, but it's just flexible enough to cause alightment issues if you're not careful during fabrication. I used 3/4" and 1" SS angle for anything exposed to flame or rough contact to kegs, the top of the frame has 1" flat bar SS overlaid to help prevent rusting. 24 gauge SS was used for the wind guards and do a reasonable enough job during the rare socal windy days.
The wheels are 3", from "Hand Trucks and Casters" for $3.72/ea, but i do wish i went slightly larger so the wheels don't get stuck as easily. The MLT tippy is also compact as well, i use an upside-down keggle so i made some handle hooks to keep everything tight (see really bad welding job below, SS is an entirely PITA to work with) . The hinges for the tippy are SS marine/boat hinges from ebay, they're just big enough to do the job.
Propane plumbing is 1/4" copper coil with brass fittings from home depot that feed the 10" banjo burners.
* replace CFC with plate chiller to make room for pumps
* mount & hardwire pumps, electric start for burners
* add more shelving, there's unused volume behind the burners during storage