My wife and I got the inspiration for this homemade outhouse costume from this website. While it could be borderline offensive to some people, I still felt comfortable wearing it among business colleagues and would-be customers. It will make for an easy ice-breaker later down the line, ("Hey, remember me? I'm the guy from the homemade outhouse costume...!")
We used a large box found off Craigs list (free) and shaped out the inner frame. To help support its weight make it durable for taking to the bars, we added 3/4" x 1 1/2" poplar boards fastened together with finish nails to keep it strong. Lucky for us because a few people tried to knock me over on the dance floor!
The roof had painted-on shingles, though it is difficult to see from the pictures shown. We used green to help contrast the brown siding, which was mostly glued-on strips of contact paper but filled in with some regular marker to highlight the wear and tear of a typical outhouse. We considered using real shingles, but their weight would be too cumbersome to carry around all night and they are prone to fall off.
The real trick on this homemade outhouse costume were the hidden straps underneath the flannel shirt. Notice that I can hold a newspaper with both hands and the box is still off the ground. It is a good idea to pad them with softer fabric because it does tend to wear on your shoulders! The door has a half-moon cut out as well as a grab-rope to open/close the door.
The shoes and pants are simple - just be sure to tape/glue them to the box so they don't fall off. The legs are just stuffed leggings with extra detail on the knobby knees. Simple add-ons like the toilet paper and "occupied" sign are glued on. We added some spider webs and graffiti inside... a person even added their own phone number (or someone else's!) while out on the town! The flannel shirt and hat added some extra character because people out in the woods typically are accustomed to using other than traditional plumbing.
I must say, this is one of the most noticeable costumes you can make. It is comfortable, warm (perfect for a crisp Minnesota late autumn evening), and helped keep a couple feet from everyone else when navigating the bars/dance floor if you are concerned about airborne germs.
If you can invest the time and the ability to haul it around in a larger vehicle, you should have no problem winning just about any costume contest. While costing less than $10, It earned us valet parking and tickets right behind home plate at a MN Twins game!