Fulton County, IL Insulation Payback
Fulton County, IL: what topping up your attic actually costs
Fulton County, Illinois is zone 5 under DOE's climate map (Cold), which means winters that dominate the energy bill, with cooling a minor factor. 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 years at an estimated $1,707/year saved.
That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $1,520/year heating, $186/year cooling. Out of every 100 US counties tracked here, Fulton County's savings potential beats roughly 66 of them. Within zone 5 specifically, it ranks 479th of 754 counties by estimated savings. Illinois averages $1,642/year across the counties tracked here; Fulton County comes in 4% higher.
The climate data behind this
The heating and cooling degree days behind this estimate — 5,686 HDD and 1,161 CDD (base 65°F, 1991-2020 normals) — come from Havana, IL US, the nearest NOAA station with published normals, 13.3 miles from Fulton County's center. By total degree days, Fulton County sits at the 68th percentile nationally. Fulton County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
The smaller top-up scenario
If Fulton 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 $249/year — payback about 9.2 years. This one is a genuine toss-up, not a clear yes.
Getting it done in Fulton County
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 Fulton County job, not a quote. You should get more than one quote before signing anything - expect at least a $600 minimum charge from most contractors.
Nothing here is a guess
Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-60 is the target here specifically.