Super Insulated Walls

We have been talking with Roxul  makers of the arguably the best batt insulation available. They are interested in being part of our project and of suggested that their newer product called Comfort Board would be a better way to reach our goals of R44.  This product would be installed exterior to the building sheathing, on the outside of the framing.  Exterior insulation like this makes for a continuous building envelope that is more efficient.  With any luck Roxul will be able to support our project in a big way.