Was thinking to simplify plumbing and as cabin is on piers to put in a raised floor in bathroom. Was thinking of using 2x 6s at right angles to main floor joists . That way would have only two penetrations in main floor, water in and waste out.
As walls on main floor are going to be 10 foot losing 6" is not a big deal. Anyone done this? See and problems.
You see this done in basements and older houses where you can't get at the plumbing from below.
The main problem is the step, which you will get used to.... but your guests won't and they can trip. Might be better to NOT have it right at the door (~3' in front? and paint a red stripe on it?) ::)
Send pictures when you do this.
Actually the penetrations of the floor are pretty well covered. incoming water through the walls, outgoing from the sink might go the same way, tub/shower and toilet by the floor.
Off-hand I'd think that building a sub-joist insulation pocket (parallel to the existing joists gives you more room) might be easier and safer.
Think kitchen, utility room if it's separate from the kitchen too.
Now I did live in a dupex in Indiana once where (only) the (connected) bathtub drains for both units froze every time there was enough water in shallow ponds for ice skating. But a lot of the fiberglass insulation had fallen out under the houses.
That would be the other option , to run the drainage piping down below the joists connect there. Could to but as this will be mostly a weekend place will have to drain everytime before living. Now could heat race drain piping. That is option.
What planning to do was have bathroom , utility room ( hot water heater, washer /dryer etc) and kitchen beside each other so no piping in walls of floor.