Tazewell County, IL Insulation Payback
Tazewell County attic insulation, by the numbers
Tazewell County sits in IECC climate zone 5 (Cold) — a real winter that drives most of the annual energy bill 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 2.1 years at an estimated $1,687/year saved. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $1,501 a year on the heating side, $186 on cooling. By estimated insulation savings, Tazewell County lands in the 65th percentile nationally. Zone 5 alone covers 745 counties in this dataset, and Tazewell County comes in 504th by savings. Illinois averages $1,642/year across the counties tracked here; Tazewell County comes in 3% higher.
Where these numbers come from
The heating and cooling degree days behind this estimate — 5,614 HDD and 1,157 CDD (base 65°F, 1991-2020 normals) — come from PEORIA GTR PEORIA AP, IL US, the nearest NOAA station with published normals, 14.1 miles from Tazewell County's center. By total degree days, Tazewell County sits at the 67th percentile nationally. One local detail the R-value alone won't tell you: Tazewell County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
Already have some insulation?
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $246/year saved — roughly 9.3 years to break even. Call this borderline rather than a clear win.
Getting it done in Tazewell County
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 Tazewell County's estimated $1,687/year on the line.
Where these figures come from
Tazewell 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.