Custer County, SD Insulation Payback
Custer County attic insulation, by the numbers
Custer County, South Dakota is zone 6 under DOE's climate map (Cold), which means a real winter that drives most of the annual energy bill here. 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.
Where the savings come from
Split it out and it's roughly $2,180 a year on the heating side, $34 on cooling. By estimated insulation savings, Custer County lands in the 91th percentile nationally. Zone 6 alone covers 459 counties in this dataset, and Custer County comes in 173rd by savings. South Dakota averages $2,162/year across the counties tracked here; Custer County comes in 2% higher.
The climate data behind this
Custer County's climate figures — 8,152 heating and 210 cooling degree days a year — are read from CUSTER CO AP, SD US, 8.2 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Custer County in the 89th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Custer County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
Already have some insulation?
A shallower starting point changes the math: with R-11 already down, only the gap to R-49 needs filling, at roughly $2,280 for an estimated $323/year saved (~7.1-year payback). Worth doing on the numbers alone.
Getting it done in Custer County
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 Custer County's estimated $2,213/year on the line.
Where these figures come from
Custer 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.