I am in the process of getting a 68x42 pole barn built. I have been debating on how to insulate the building. Originally, the plans called for the 2.5 inch vapor barrier beneath the metal that also has a little fiberglass and is rated at r6 but when compressed it yields less. I have read a bunch online about guys insulating with batt insulation instead of the fiberglass blankets that get installed between the wood and metal. I plan to install a propane heater up in the ceiling at set it around 40 when not in there and up to 55 when working on the weekends. Will this 2.5 insulation do ok and not kill me on heating costs? Our climate is a milder than alot of the online discussions. The builder says I can go heavier on the fiberglass blanket to a 3 inch which is r10 but to do that I would also need to upgrade the metal to 26 gauge from 29 so it doesnt get a wavy appearance on the outside. Other options include getting 6' walls put in and install batt insulation rolls etc and cover with plywood and install a ceiling below trusses and have insulation put up there. I wasnt sure if all that money spent doing that would be worth it. Any comments or suggestions would be appreciated. At this point, the builder has all the posts set and is getting read to raise the trusses in the next week. Its 68 long by 42 wide with 4 14ft wide bays that have 12x14 insulated roll up doors and one additonal 12ft bay with a mandoor and posts to build a loft up above. To save on heating, I will likely put in a divider wall so that I am only heating the 12ft bay plus two 14ft bays. 6 inch concrete all around. Radiant heat has been mentioned as an option also but for my application (not being out there everyday), not sure it would be worth it. Thanks for any help.