Corson County, SD Insulation Payback
Corson County attic insulation, by the numbers
Corson County, South Dakota is zone 6 under DOE's climate map (Cold), which means winters that dominate the energy bill, with cooling a minor factor. An uninsulated attic there should be built up to R-60. Going from R-2 to the recommended R-60 costs roughly $3,480 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 1.6 years at an estimated $2,213/year saved. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $2,112 a year on the heating side, $101 on cooling. By estimated insulation savings, Corson County lands in the 91th percentile nationally. Zone 6 alone covers 459 counties in this dataset, and Corson County comes in 172nd by savings. South Dakota averages $2,162/year across the counties tracked here; Corson County comes in 2% higher.
Where these numbers come from
NOAA's MC INTOSH 6 SE, SD US station, 11.5 miles from Corson County, supplies the 7,897 HDD and 629 CDD this estimate runs on. That combined heating-and-cooling load ranks Corson County 283rd nationally by total degree days — the 91th percentile. One local detail the R-value alone won't tell you: Corson County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
Already have some insulation?
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $323/year saved — roughly 7.1 years to break even. Worth doing on the numbers alone.
Next steps for a Corson County attic
Get more than one quote before committing. Attic access and any needed air sealing move the price around, and most contractors won't take a job below roughly $600 regardless of size - worth asking upfront given Corson County's estimated $2,213/year on the line.
Where these figures come from
Corson County's R-60 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-60 is the target here specifically.