We recently bought a 1950's home, interior is lathe on block, exterior is stucco. These homes were built great but lack insulation. Rather than sacrifice interior space, I would rather install exterior insulation like rigid form board, InSoFast, or something similar and then siding over it. The stucco is in good shape and the cost of removing stucco first seems unnecessary. Are there any other insulation plans I sould be considering that are either more cost effective or more efficient. We live in PA and winters here without insulation can be harsh. Any thoughts or help is welcome. Thanks!