Clark County, SD Insulation Payback
Attic insulation payback for Clark County, SD
Clark County sits in IECC climate zone 6 (Cold) — winters that dominate the energy bill, with cooling a minor factor. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to R-60. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-60 runs an estimated $3,480, and saves about $2,356 a year in heating and cooling — a payback around 1.5 years. Hard to find a home improvement with a faster payback than this.
Where the savings come from
Of that, about $2,269/year comes from reduced heating and $87/year from reduced cooling load through the ceiling. Clark County beats 95% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 459 counties DOE places in zone 6, Clark County ranks 57th. Against South Dakota's own average of $2,162/year, Clark County runs 9% above that.
Where these numbers come from
NOAA's CLARK, SD US station, 1.9 miles from Clark County, supplies the 8,486 HDD and 540 CDD this estimate runs on. By total degree days, Clark County sits at the 95th percentile nationally. DOE also classifies Clark County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
If the attic isn't bare
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $344/year saved — roughly 6.6 years to break even. Topping up the attic pays for itself here.
Next steps for a Clark County attic
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $3,480 as a starting estimate for a Clark County job, not a quote. Expect at least a $600 minimum charge from most contractors.
More on how this was built
Nothing here is a guess: the methodology guide names the DOE climate map and NOAA station data behind every number on this page. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.