Cass County, IA Insulation Payback
Attic insulation payback for Cass County, IA
DOE classifies Cass County as climate zone 5, cold — a real winter that drives most of the annual energy bill here. 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 $1,926 a year — payback in roughly 1.8 years. Hard to find a home improvement with a faster payback than this.
Where the savings come from
Of that, about $1,775/year comes from reduced heating and $151/year from reduced cooling load through the ceiling. Cass County beats 78% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 745 counties DOE places in zone 5, Cass County ranks 118th. Against Iowa's own average of $1,985/year, Cass County runs 3% below that.
The climate data behind this
Cass County's climate figures — 6,638 heating and 940 cooling degree days a year — are read from ATLANTIC 1 NE, IA US, 6.9 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Cass County 628th nationally by total degree days — the 80th percentile. DOE also classifies Cass County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
Already have some insulation?
If Cass 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 $281/year — payback about 8.1 years. It is close - the payback only just fits a reasonable timeframe.
Next steps for a Cass 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 Cass 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.