The Incred-I-Box 16’ and 20’ are foam sandwiched between metal panels on heavier trailer frames that are certified nationally as RVs that are basically roughed out tiny homes with lots of options. The only wood is the floor framing. The last time I checked they are starting at $20,000 and top out at $35,000 for a full off grid set up with options within that price range of solar, on demand water heater, composting toilet, black, gray and water catchment as well as ceramic and solar heat. The 16’ is supposedly under 5,000 lbs. Pretty exciting if you ask me! I think they will be in Quartzsite this year.