I want to enclose my New York timberframe home with polyurethane panels. The prices of polyurethane sips is more than I want to spend. I am considering using panels made by Ray-Core, http://www.raycore.com/ , which do not have any skins such as OSB, or drywall. I know that studs will conduct some cold, but I like the idea of having something substantial to nail and screw. The Ray-Core panels I can install myself without a crane, another plus for me. The Ray-Core roof panels have 2 x 6 douglas fir studs acting as purlins. Has anyone out there have any experience using this system or opinions vs using sips?