I started building this tiny house back in 2016. Over time, I decided that life wasn't for me so I never finished the interior of the build.
This completed shell is built upon a 24' Iron Eagle PAD trailer purchased in 2016 for ~$5000. The roof and outside walls are covered in white metal siding attached to house wrapped plywood and 2x6 framing.
Under the subfloor is 5.5" of foam board insulation, giving an R-value of 26. The framing uses 2x6s to allow more room for insulation and 24" stud spacing while maintaining excellent rigidity.
The ceiling height and roof slope is based on the most headroom possible while staying under legal height limits for towing without requiring a permit.
There is an Energy Recovery Ventilator (ERV) mounted above what was going to be the bathroom, so that is included along with the vent connector to the outside and some insulated ducting (the cardboard box wedged between the studs near the back).
Electric circuits are routed based on what made sense for my build plan, but might require relocation for yours.
The trailer it is built on is capable of holding 10000lbs, but I haven't weighed the shell as is, so I would plan on bringing a truck that can tow quite a lot just in case. We hired a tow truck the two times we had to relocate it over the years and that worked great.