Gibson County, IN Insulation Payback
Gibson County, IN: what topping up your attic actually costs
Gibson 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. 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 $1,525 a year — payback in roughly 2.3 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $1,316/year heating, $209/year cooling. Out of every 100 US counties tracked here, Gibson County's savings potential beats roughly 54 of them. Within zone 4 specifically, it ranks 138th of 825 counties by estimated savings. Indiana averages $1,634/year across the counties tracked here; Gibson County comes in 7% lower.
The climate data behind this
The heating and cooling degree days behind this estimate — 4,920 HDD and 1,303 CDD (base 65°F, 1991-2020 normals) — come from PRINCETON 1 W, IN US, the nearest NOAA station with published normals, 2.8 miles from Gibson County's center. Combined heating and cooling load puts Gibson County in the 57th percentile of this 3,162-county dataset. Gibson 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 Gibson 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 $222/year — payback about 10.3 years. This one is a genuine toss-up, not a clear yes.
Next steps for a Gibson 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 Gibson 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.