Which Wall and Roof Insulation to use?
I've already accepted a floor plan and my footings are in, but I would like to know what wall system I should be using. My bid was for 2x6 walls, 16" on center with 1/2" osb sheeting and vinyl siding. The insulation was to be R19 Batts (I'll at a minimum upgrade to R21) with a vapor barrier on the outside of the home and sheetrock on the inside. I'm wondering if I go with a 3/4" or 1" foam with taped seams under the vinyl siding but on top of the OSB sheeting, R21 Batts and a smart vapor barrier under the sheetrock if I will meet code and second if it is worth the extra couple thousand it will cost me. For reference, I am in North Dakota at the edge of zone 6 and am doing a geothermal HVAC system.
I will have vaulted ceilings so I have no idea how that will be done but am interested in finding out what I can do to help there as well.
Finally, I'm building on a full basement (6' to grade). I wont have anything under the slab, but is it worth it to put an inch of foam outside the slab? I would like to match it up to the upstairs for width.
Just for reference, my floorplan is already accepted as well as the bid, but I think this could be a worthwhile upgrade, particularly if I do the foam myself.
If you need more information about my project to make an informed decision I've put a link to my build log below.
Here is a link that might be useful: www.ultimatehomestead.com