Adams County, IL Insulation Payback
Adams County attic insulation, by the numbers
Adams County, Illinois is zone 5 under DOE's climate map (Cold), which means a real winter that drives most of the annual energy bill here. An uninsulated attic there should be built up to 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 $1,652 a year — payback in roughly 2.1 years. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,467 a year on the heating side, $185 on cooling. By estimated insulation savings, Adams County lands in the 63th percentile nationally. Zone 5 alone covers 745 counties in this dataset, and Adams County comes in 567th by savings. Illinois averages $1,642/year across the counties tracked here; Adams County comes in 1% higher.
The climate data behind this
Adams County's climate figures — 5,486 heating and 1,153 cooling degree days a year — are read from QUINCY RGNL AP, IL US, 3.4 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Adams County in the 65th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Adams 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 $241/year saved (~9.5-year payback). Call this borderline rather than a clear win.
Quotes and materials for this job
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 Adams County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Adams 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.