I just finished a house that took me two years to build and this is our first winter. The house is a modified post and beam and is completely open on the upper level. On the lower level it is open half way with beedrooms etc forming the support for the loft.I have 8 1/4 insullating panels on the roof with a vapor barrier under them as the mfg recommented.
My problem is that I get moisture where the upper and lower sashes of the windows meet.The colder it gets the more moisture. I have radiant heat between the floor joists in the basement. I have 2×6 walls and sealed the place really well when building it. The humidity hovers around 70 % which is too high and I realize it probably is the cause but I can think of no reason why it is so high. There is nothing in the house that would create abnormal humidity.