Ray Cohen wrote:
Hello, Mike and Maggie. I was just reviewing your Green Home Blog. I know you are happy to be able to actually see progress being made. I was wondering if you might know what the R value is in the SIP wall panels containing the foam insulation and also what the actual thickness would be. Just curious. I hope you guys are doing well. Goooo Cocks!
Here is the answer from our architect:
“The SIP panels have a true r-value of 17 + siding and interior finish which adds maybe 2. Whereas fiberglass insulation has an r-value of 13 for the same thickness wall however the overall performance of a conventional wall has an air loss factor and thermal bridging due to studs every 16” on center. The result is that the r value of a 4 ½” SIP wall acts like an 8” stud wall.”
The SIP walls are 4 1/2" thick and the roof SIP's are 10 1/2".