Henderson County, IL Insulation Payback
Henderson County, IL: what topping up your attic actually costs
Henderson County sits in IECC climate zone 5 (Cold) — winters that dominate the energy bill, with cooling a minor factor. 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 years at an estimated $1,743/year saved. That's about as fast as attic paybacks get.
Heating vs. cooling in Henderson County
The estimated savings split roughly $1,565/year heating, $178/year cooling. Out of every 100 US counties tracked here, Henderson County's savings potential beats roughly 69 of them. Within zone 5 specifically, it ranks 402nd of 745 counties by estimated savings. Illinois averages $1,642/year across the counties tracked here; Henderson County comes in 6% higher.
Where these numbers come from
Henderson County's climate figures — 5,853 heating and 1,108 cooling degree days a year — are read from GLADSTONE DAM 18, IL US, 6.3 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Henderson County in the 71th percentile of this 3,162-county dataset. Henderson County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
Already have some insulation?
If Henderson 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 $254/year — payback about 9 years. This one is a genuine toss-up, not a clear yes.
Quotes and materials for this job
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 Henderson County, not a bid - contractors typically charge a $600 minimum regardless of job size.
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.