Vanderburgh County, IN Insulation Payback
Vanderburgh County attic insulation, by the numbers
Vanderburgh County, Indiana is zone 4 under DOE's climate map (Mixed-Humid), which means real heating and real cooling seasons both, roughly balanced across the year. An uninsulated attic there should be built up to R-60. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-60 runs an estimated $3,480, and saves about $1,323 a year in heating and cooling — a payback around 2.6 years.
Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,038 a year on the heating side, $284 on cooling. By estimated insulation savings, Vanderburgh County lands in the 40th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Vanderburgh County comes in 539th by savings. Indiana averages $1,634/year across the counties tracked here; Vanderburgh County comes in 19% lower.
The climate data behind this
NOAA's Evansville Museum, IN US station, 3.9 miles from Vanderburgh County, supplies the 3,883 HDD and 1,771 CDD this estimate runs on. That combined heating-and-cooling load ranks Vanderburgh County 1797th nationally by total degree days — the 43rd percentile. One local detail the R-value alone won't tell you: Vanderburgh County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
If Vanderburgh 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 $193/year — payback about 11.8 years. Call this borderline rather than a clear win.
Next steps for a Vanderburgh County attic
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 Vanderburgh 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.
Where these figures come from
Vanderburgh 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.