N Scale Small Railroad Structures
These are a models of: a whistle stop depot (15' by 10'); a crossing shanty (5' by 5'); a speeder shed (18' by 12'); and a general storage shed (10' by 15'). If you wish to add roof overhangs you can put paper or thin card on the roof of each structure.
I print my models on a filament (FDM) printer. That's what they're designed to be printed on. I printed these structures at 50% infill. Print the structure floor-side down and no supports will be needed.