Wabash County, IL Insulation Payback
Wabash County attic insulation, by the numbers
DOE classifies Wabash County as climate zone 4, mixed-humid — a genuine mix of cold winters and humid summers, with neither one dominating the bill. Its recommended attic R-value for bare joists is 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 2.4 years at an estimated $1,449/year saved. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,214 a year on the heating side, $234 on cooling. By estimated insulation savings, Wabash County lands in the 49th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Wabash County comes in 274th by savings. Illinois averages $1,642/year across the counties tracked here; Wabash County comes in 12% lower.
The climate data behind this
The heating and cooling degree days behind this estimate — 4,541 HDD and 1,459 CDD (base 65°F, 1991-2020 normals) — come from MT CARMEL, IL US, the nearest NOAA station with published normals, 5 miles from Wabash County's center. By total degree days, Wabash County sits at the 52th percentile nationally. One local detail the R-value alone won't tell you: Wabash County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $211/year saved — roughly 10.8 years to break even. Call this borderline rather than a clear win.
Next steps for a Wabash 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 Wabash County's estimated $1,449/year on the line.
Where these figures come from
Wabash 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.