You can search online, treehugger, barntoolbox all come up, you should be more specific, how tall does it need to be, what king of roof are you looking at, what is its purpose (does it need electical,water etc.) I did a quick search for a 50x50, hope this helps https://barndominiumideas.com/50x50-barndominium-floor-plans/ just remove interior load bearing walls to customize The most important parts will be your structural walls and truss layout for the roof. If you plan on parking heavy equipment, ideally you will want at least a 6" concrete floor with 5000 psi concrete, however, 95%-97% compacted soil might do the trick depending on the weight of the equipment.