Calhoun County, IL Insulation Payback
Calhoun County, IL: what topping up your attic actually costs
DOE classifies Calhoun County as climate zone 5, cold — cold enough that heating, not cooling, is what decides the bill. Its recommended attic R-value for bare joists is 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 $1,560 a year — payback in roughly 2.2 years. That's about as fast as attic paybacks get.
Heating vs. cooling in Calhoun County
The estimated savings split roughly $1,374/year heating, $186/year cooling. Out of every 100 US counties tracked here, Calhoun County's savings potential beats roughly 57 of them. Within zone 5 specifically, it ranks 685th of 745 counties by estimated savings. Illinois averages $1,642/year across the counties tracked here; Calhoun County comes in 5% lower.
The climate data behind this
Calhoun County's climate figures — 5,140 heating and 1,159 cooling degree days a year — are read from ELSBERRY 1 S, MO US, 6.3 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Calhoun County in the 58th percentile of this 3,162-county dataset. Calhoun County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
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 $228/year saved (~10-year payback). This one is a genuine toss-up, not a clear yes.
Getting it done in Calhoun County
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 Calhoun 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.