Just got the county to approve the plans & issue building permit.
Some changes:
Due to polyiso foam R-value dropping by 2/3 at 0*F I changed all the exterior walls buildup to 3" type 2 EPS on outside, them 4" polyiso on inside, where it won't get as cold & drop so much R-value.
The county didn't require any additional ignition or thermal barrier to be applied over the closed cell spf on the underside of the roof sheathing. This is probably due to the very limited access.
R-38 is minimum requirement here (5.5")
I will pay extra to have the 2x6 rafters & the wall top plates completely encapsulated.
This will increase the R-value to about R-50, improve infiltration, & water vapor management.
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