Insulation quotes in... now I have to decide
We are building a 5200 sq ft one story home in central NC (zone 4). Exterior walls 2x6 16" OC. All ducts will be in the sealed crawlspace, and all quotes below include sealing the crawl. Because of the large sq footage of roof and no air ducts in the attic, we are not interested in insulating at the roofline. We do plan to have a radiant barrier on the roof.
$11K = R-19 Rolled batts in walls, blown fiberglass attic to code
$15K = R-22 Asure-R Blown-in fiberglass in walls, blown fiberglass attic to code
$23K = R-18 3in closed cell foam in walls, 6in at ceiling level to code
Because of the numbers, we are leaning towards the Asure-R blown in fiberglass. Foam just doesn't seem to be justifiable. I like the continuous and consistent nature of the blown in fiberglass as opposed to batts.
Will I still need 1" XPS (R-5)or just zip sheathing? Also considering ZIP R sheathing instead(R-6)... any feedback on this would be great as it is a new product which combines housewrap, rigid foam, air barrier all in one product.
What else do I need to be thinking about? I appreciate all feedback. I have been learning a lot about insulation, but still do not understand much! Thanks in advance.