You should be able to fully insulate your van with havelock wool sheep s wool insulation for about 300 to 600 including shipping depending on the size of your van.
Insulate and carpet van.
I recently have started living in a van 3ish months now it s a 2003 dodge ram 2500 van extended it was previously used by my grandfather for carpet and lino installs and because of the glue s that he used he had already carpeted it and insulated and put wood paneling on the walls and roof.
We decided that rather than paneling the van walls with wood we would carpet it to get a better finish and make it seem warmer.
In addition to that we also made reflective insulating.
Note that there was condensation everywhere outside on the van on the ground etc.
That gives great insulation and sound proofing.
We used the kiravans easyliner 4 way stretch carpet in wheat to get a nice warm but light look to the van.
It means all the frames inside the van had no insulation on them.
We re coming out with an even more detailed post on all aspects of van insulation soon so stay tuned.
This photo was taken during the conversion without ez cool installed.
Using foam board you should be able to fully insulate your van for about 150 to 250 we spent about 150 to insulate our standard wheelbase chevy express.
As far as costs we spent about 150 on the insulation 2 sheets of 3 4 polyiso 4 cans of spray foam 1 roll of fiberglass 1 roll of reflectix and 2 cans of spray adhesive.
Foam board works for insulating van floors as long as it s between framing members with rigid flooring over top so it won t get broken down under the weight of furniture equipment and walking i believe that mass loaded vinyl is a much better option on floors.
I leave the floor insulation that comes with the van as that adds to the insulation.
Don t try it when it is windy unless you have more than two people.