My Only problem with no build builds is that if you use a cargo vehicle there’s nothing On the walls or ceiling to Prevent heat transfer. It’s just not practical to live in something like that. It even affects your storage of things, especially food. A good quality tent is it much better structure to live in for comfort than a “bare skin” van. For occasional travel it could be ok but to live in, I just can’t see It. If you use a passenger vehicle at least you have some proTection from the bare metal skin. I have lived full time in my van for a year now. It is a full size Dodge conversion. I removed all the seats except the drivers. I tore out the carpet replaced it with half inch inch insulation, half-inch plywood, and vinyl flooring. The only insulating I did was to the 3 large windows which I covered with 3/4 inch polyiso wrapped in fabric. My ceiling and side walls I left just as the conversion company made them. It is not the best insulation but far better than the metal skin. My first vehicle which I part time in for over a decade was a GMC Safari that was Used as a worksite office for bell tell who carpeted the walls, floor, and ceiling, I just built a bookshelf/desk on the passenger side and a storage box/bed on the other. I don’t want to be critical of others, just putting in my 1 cent (I don’t have 2)