I am remodeling a house in Sacramento, California.
I have stripped it down to the subfloor of its original foundation. I am interested in making it very energy efficient. I am thinking of 2×6 walls with a R-22 fiberglass batts, 2-coat stucco over 1″ foam board, and a layer of 3/4″ polyboard under the sheetrock at all exterior walls. R-8 flex duct and HVAC units of 90% ++ efficiency to be in attic. I am considering spray foam insulation to be applied underneath solar board with a light colored comp or metal roof on top. Attic to be tight unvented type. Should I consider additional foam above roof sheathing with a additional layer of sheathing or would this be both too costly and not very effective ?? Should I consider still insulating the ceiling with a additional layer of R-19 since the spray foam will give me about a R-20 ??
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