My home has too many windows, so it wouldn be practical to use Eco-Panels or even SIPs in general, correct?
Wrong. As we have previously discussed whole wall insulation is all about the weighted average of the individual R-values of the components in the wall. Even good windows typically only have R values (inverse of U-factor) of around 3.5 and so large windows can dramatically reduce the whole wall effective R value (see the link http://www.nfrc.org/ for some great window information resources). To offset the dramatic decrease of the insulative properties of a wall with windows it is imperative that you use a highly insulative material like Eco-Panels, offering R26 or R40 wall panels. Standard fiberglass or open cell spray foam products have whole wall effective R values of less than half of Eco-Panels.
