@2hams Correction Montana High Country does indeed provide their construction specifications it can be found in their brochure which can be found at the following link. http://www.keystonerv.com/media/598276/2013_MontanaHighCountry_Brochure.pdf. I am certain the other manufacturers also provide their construction specifications. By construction specification one would consider the materials used in the walls, ceilings, flooring, windows, suspension, etc. For example wall are constructed from 2 inch welded aluminum studs, roof 5 inch thick arched rafters, floor Laminated floor with 3” thick aluminum floor joists & high density block foam to list a few not the manufacturer of the awning, refrigerator, toilet, thermostat.