Hi Ana and Family,
I mostly followed your plans for my remote Alaska property outhouse build, with slight modifications. Our property is 7 miles from any road (and 2.5 hr drive from Anchorage) and I typically go there in the winter via snowmobile (December-April). I built this on my back deck in Anchorage and then took it apart and transported it in sections (back wall, 2x sidewalls, floor parts, door, roof parts, seat parts). It took me 5 trips to get it all up to my property from the truck at the trailhead via snowmobile!
The hardest part was digging the hole under 5 ft of snow! I cut several dead spruce trees in the area I planned to situate the outhouse and started a big fire (really big). We kept that going until we had melted out about a 15ft wide area down to bare soil. The next morning, while the ground was still warm from the previous evening's fire, we dug the hole (only about 3.5x3.5ft). Then I cribbed in the hole with old cedar fence slats to help prevent the inevitable ground cave-in that we often see with soil melt and rains in Alaska. Then, I pieced the outhouse together, with the frame sitting on small pavers.
I used a combo of T&G pine and cedar for the walls. I used metal for the roof. As I built this in January and February over several weekends (in Alaska), it was very cold and I would take the pieces inside and paint/stain them. As such, this basically took me all winter from start to finish. It doesn't take that long if you build it on site in warm weather. Once transported to the cabin site, it took parts of 3 weekends to get it in place and useable, including site prep. I've still got a little touch-up work to do (e.g., window for light in winter and bird block to keep the spring and summer nesters out). I put some anti-slip tape on the frame so that I don't slip on the frame base.
There is some waste wood if you follow the plans directly (especially 2x6), but I am using that to build a small firewood cover at home. This was not an inexpensive outhouse even without pandemic prices (I could have chosen a less expensive siding), but I wanted a nice outhouse and I'm very pleased with the outcome, so it was money well spent. Great plans! Thanks.