Bon Homme County, SD Insulation Payback
Bon Homme County, SD: what topping up your attic actually costs
Bon Homme County, South Dakota is zone 5 under DOE's climate map (Cold), which means cold enough that heating, not cooling, is what decides the bill. An uninsulated attic there should be built up to R-60. For an attic around 1,000 square feet, closing the gap from R-2 to R-60 costs around $3,480 and saves an estimated $2,074 a year — payback in roughly 1.7 years. That's about as fast as attic paybacks get.
Where the savings come from
The estimated savings split roughly $1,940/year heating, $134/year cooling. Out of every 100 US counties tracked here, Bon Homme County's savings potential beats roughly 85 of them. Within zone 5 specifically, it ranks 16th of 745 counties by estimated savings. South Dakota averages $2,162/year across the counties tracked here; Bon Homme County comes in 4% lower.
Where these numbers come from
NOAA's TYNDALL, SD US station, 0.8 miles from Bon Homme County, supplies the 7,256 HDD and 833 CDD this estimate runs on. That combined heating-and-cooling load ranks Bon Homme County 413th nationally by total degree days — the 87th percentile. Bon Homme County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
The smaller top-up scenario
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 $303/year saved (~7.5-year payback). That is a solid payback as home upgrades go.
Next steps for a Bon Homme 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 Bon Homme County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Nothing here is a guess
Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-60 is the target here specifically.