Wapello County, IA Insulation Payback
Attic insulation payback for Wapello County, IA
DOE classifies Wapello County as climate zone 5, cold — cold enough that heating, not cooling, is what decides the bill. Its recommended attic R-value for bare joists is 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 $1,801 a year — payback in roughly 1.9 years. Hard to find a home improvement with a faster payback than this.
The breakdown behind the number
Of that, about $1,643/year comes from reduced heating and $158/year from reduced cooling load through the ceiling. Wapello County beats 72% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 745 counties DOE places in zone 5, Wapello County ranks 290th. Against Iowa's own average of $1,985/year, Wapello County runs 9% below that.
The climate data behind this
NOAA's OTTUMWA INDUSTRIAL AP, IA US station, 5.6 miles from Wapello County, supplies the 6,145 HDD and 985 CDD this estimate runs on. Combined heating and cooling load puts Wapello County in the 74th percentile of this 3,162-county dataset. DOE also classifies Wapello County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
The smaller top-up scenario
If Wapello 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 $263/year — payback about 8.7 years. It is close - the payback only just fits a reasonable timeframe.
Next steps for a Wapello 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 Wapello County, not a bid - contractors typically charge a $600 minimum regardless of job size.
More on how this was built
Nothing here is a guess: the methodology guide names the DOE climate map and NOAA station data behind every number on this page. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.