Choosing and balancing R-values
We are in Minnesota (Zone 6a). The home is an “L” shaped, 2200 sq/ft single level, slab on grade with a 28’x40′ attached garage making the “L”
I’m looking to nail down the R-values of the wall, ceiling and slab. If we do a 10″ double stud wall with dense pack cellulose (R30) and 4″ of EPS (R20) for the FPSF…what should we aim for in the ceiling? Is there a formula or rule of thumb to follow to balance these?
We are thinking 8/12 pitch gable roof, 1′ energy heel, and scissor trusses (3/12 interior pitch) over the 26 x 34 living room/kitchen/dining room area.
The reason for leaning toward a 10″ vs 12″ wall is it simply seems like a reasonable balance between cost, interior sq/ft penalty, and window view obstruction. Since I don’t yet know the actual cost difference, I no idea if this is valid or not.
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