Pope County, IL Insulation Payback
Pope County attic insulation, by the numbers
Pope County, Illinois is zone 4 under DOE's climate map (Mixed-Humid), which means a genuine mix of cold winters and humid summers, with neither one dominating the bill. 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 2.6 years at an estimated $1,348/year saved. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,125 a year on the heating side, $223 on cooling. By estimated insulation savings, Pope County lands in the 42th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Pope County comes in 489th by savings. Illinois averages $1,642/year across the counties tracked here; Pope County comes in 18% lower.
The climate data behind this
NOAA's DIXON SPRINGS AGRIC CTR, IL US station, 7 miles from Pope County, supplies the 4,206 HDD and 1,389 CDD this estimate runs on. That combined heating-and-cooling load ranks Pope County 1836th nationally by total degree days — the 42th percentile. One local detail the R-value alone won't tell you: Pope County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
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 $197/year saved (~11.6-year payback). Call this borderline rather than a clear win.
Quotes and materials for this job
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 Pope County's estimated $1,348/year on the line.
Where these figures come from
Pope 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.