Is your winter filled with cold snaps or unrelenting below-zero temperatures? To live comfortably and economically in a smaller house, we suggest paying attention to insulation quality in your walls, attic/roof and foundation underfoot.
Designed by Go Logic, this 1,000 square foot Maine home cost around $160k to build. When kept at 70 degrees all winter, energy bills ran only $1,000 annually. (Fine Homebuilding PDF)
Insulation with R-values
Insulation is measured through “the resistance of an insulating or building material to heat flow, expressed as R-11, R-20, and so on; the higher the number, the greater the resistance to heat flow.”
One well-insulated example is the Go Logic home, which achieves extremely high R-values in an affordable, smaller-size residence. Architect Matthew O’Malia reports three specific R-values:
- 24″ cellulose fills the attic floor (R-84)
- 8″ EPS-filled SIPs, 2×4 bearing wall with dense-pack cellulose (R-50)
- 12″ EPS rigid insulation below the slab foundation (R-60)
Right R-values for you
Back in 2012, the International Code Council (ICC) established R-values and other standards for new home builds. Today they are still getting adopted by local municipalities across the country.
By achieving these ICC insulation standards, however, your energy bills should be lower than typical homes. We recommend achieving (or surpassing) them in any upcoming home build.
Not sure about your climate zone? For reference, here is a color version of the USA climate zone map, from Florida (zone 1) to the upper Midwest (zone 7).
High insulation, low fenestration
Stepping back, your energy savings come from living within a smaller square foot home that also sports high R-value insulation. But wait for the rest of the story.
Fenestration is a fancy word for air flow leaks, which aren’t ideal when trying to maximize indoor warmth. Culprits include fireplace flues, windows, skylights, sliding glass doors, and other holes – and the ICC addresses them too.
For an overview that’s in plain English, we encourage you to download “Build Like This.” Here’s to your small house and its thermal envelope!