We started building a THOW, then life happened. We've put 22k into it (including the custom trailer) hence the starting price of $22k, but this is negotiable.
About the design:
"General": Floor is 2x4 framed with R21 worth of foam board insulation between the "floor joists". If you're familiar with the concepts of thermal bridging, a subfloor directly on the trailer wouldn't be a good idea for colder climates. 2x4 framed walls should allow for the same amount of insulation (or spray foam). Window headers, roof pitch, rafter sizing/spacing all done based on snow loads up to 60lb/sqft (upper midwest) following IRC and WI building codes (only state in the US which doesn't use IRC). All windows are double pane from Marvin. Trailer is a custom 28' (20' bed, 8' gooseneck) from Tiny House Basics, rated up to 14klb.
"Full Bedroom": The gooseneck and partial "shed roof", allows for full standing height in the "master bedroom" (for me at least, 5'10"). You also get the huge pair of windows in the bedroom (3' square!), both of which open all the way out. The goose is 42" above the bed, so there's room for normal stairs leading up to the bedroom (ease of access).
"Bathroom": located towards the stern, and sized to allow for a 48"x36" soaking tub (included!), toilet, and sink in the middle. A fun little diagonally-mounted square 24" window in front of the sink allows a nice view out. Above the bathroom you have a loft for storage (or second bed).
"Kitchen/living room": located along the port-side wall, with allowance for plenty of countertop space and a full-sized couch. Two windows are located on this wall, one where we envisioned the sink, and one behind the sofa. On the starboard side is a massive window (36"x48") which swings open vertically, doubling as a sort of awning for a deck to be built outside the door, and serving to join outdoor/indoor spaces (e.g.put a bar-top under the window!).
Call or text Thomas for a showing: 630-450-5426