Hardin County, IL Insulation Payback
Hardin County attic insulation, by the numbers
Hardin County sits in IECC climate zone 4 (Mixed-Humid) — heating load in winter and cooling load in summer, both worth taking seriously here. For a currently uninsulated attic, DOE and ENERGY STAR recommend building 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 2.4 years at an estimated $1,466/year saved. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,284 a year on the heating side, $182 on cooling. By estimated insulation savings, Hardin County lands in the 51th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Hardin County comes in 240th by savings. Illinois averages $1,642/year across the counties tracked here; Hardin County comes in 11% lower.
Where these numbers come from
The heating and cooling degree days behind this estimate — 4,803 HDD and 1,131 CDD (base 65°F, 1991-2020 normals) — come from ROSICLARE 5NW, IL US, the nearest NOAA station with published normals, 8.5 miles from Hardin County's center. That combined heating-and-cooling load ranks Hardin County 1574th nationally by total degree days — the 50th percentile. One local detail the R-value alone won't tell you: Hardin County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
If Hardin County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-49. That smaller top-up costs around $2,280 and saves an estimated $214/year — payback about 10.7 years. Call this borderline rather than a clear win.
Next steps for a Hardin County attic
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $3,480 figure above as a planning number for Hardin County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Hardin 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.