House: 3600 heated sqft
Window NFRC: U-Factor 0.27, SHGC 0.24
Thermal Break: ½” DOW SIS Board
Annual savings: $50
Payback: 52 years
Needless to say we did not frame with 2x6 walls. The investment just didn't make sense. I should point out one more item. If you missed it, we are cooling this house at a rate of 900 sqft per ton (3600sqft/4tons).
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