R Value of Stucco Styrofoam?

We are building a home in Bay Ridge that will have an exterior finish of stucco. My contractor has offered to use 4 inch styrofoam to apply the stucco to because it will act as a better insullator as compared to the more standard 2 inch strofoam boards. Does anyone know the R value per inch of typical styrofoam board?

By dssguy99 | 11/02/2009 8:08 AM