Scott County, IA Insulation Payback
Scott County attic insulation, by the numbers
Scott County, Iowa 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. 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 $1,833 a year in heating and cooling — a payback around 1.9 years. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $1,691 a year on the heating side, $141 on cooling. By estimated insulation savings, Scott County lands in the 74th percentile nationally. Zone 5 alone covers 745 counties in this dataset, and Scott County comes in 235th by savings. Iowa averages $1,985/year across the counties tracked here; Scott County comes in 8% lower.
The climate data behind this
Scott County's climate figures — 6,326 heating and 879 cooling degree days a year — are read from DAVENPORT, IA US, 3 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Scott County 786th nationally by total degree days — the 75th percentile. One local detail the R-value alone won't tell you: Scott 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 $267/year saved (~8.5-year payback). Call this borderline rather than a clear win.
Quotes and materials for this job
Get more than one quote before committing. Attic access and any needed air sealing move the price around, and most contractors won't take a job below roughly $600 regardless of size - worth asking upfront given Scott County's estimated $1,833/year on the line.
Where these figures come from
Scott 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.