I ended up using 2 boxes of havelock and 1 of thinsulate. I did both because I didnt want to pay $50 shipping for 1 more box havelock so I ordered thinsulate from Amazon. Same price for both except the $50 shipping with havelock that you cannot remove which sucks. I double insulated the roof and single insulated everything else and got into the nooks, on top of the front headliner, as well as bith bavk foors and sliding door. Figured id let yall know if it would help out anyone. In total about 300 sq ft. This doesn't include the flooring. Also havelock does have a smell to it but it just smells like a farm. Not bad but noticeable while youre installing it. Slight smell in the van before it was covered. But I have a really sensitive sense of smell so some might not smell it. Its not bad. Just came back from camping for a week in the pnw where it was around 40 overnight. I dont have fans or ac other than the stock rear ac and it maintained heat well enough to where we slept uncovered most nights. I would put the heater on for 10 min before going to bed. Also had window covers all around so that probably helped too. Overall I think both insulation are good enough after feeling both. Thisulate is definitely easier to work with, but does feel like havlock encompases more area although both are 2". It is a lot easoer to source and it come with 2 days shipping from amaazon which is great. Havelock is way better when having to get into the nooks and cranies, sucks putting in the roof and is just slacks down. Also that $50 shipping hurts my soul. Hope this help someone