Jefferson County, IN Insulation Payback
Jefferson County attic insulation, by the numbers
Jefferson County, Indiana is zone 4 under DOE's climate map (Mixed-Humid), which means a genuine mix of cold winters and humid summers, with neither one dominating the bill. 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 $1,419 a year — payback in roughly 2.5 years. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,212 a year on the heating side, $207 on cooling. By estimated insulation savings, Jefferson County lands in the 47th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Jefferson County comes in 346th by savings. Indiana averages $1,634/year across the counties tracked here; Jefferson County comes in 13% lower.
Jefferson County's actual weather, not a national average
The heating and cooling degree days behind this estimate — 4,532 HDD and 1,288 CDD (base 65°F, 1991-2020 normals) — come from MADISON SEWAGE PLT, IN US, the nearest NOAA station with published normals, 4.1 miles from Jefferson County's center. Combined heating and cooling load puts Jefferson County in the 48th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Jefferson County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
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 $207/year saved (~11-year payback). Call this borderline rather than a clear win.
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 Jefferson County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Jefferson 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.