Union County, IL Insulation Payback
Attic insulation payback for Union County, IL
Union County, Illinois 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. Going from R-2 to the recommended R-60 costs roughly $3,480 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 2.6 years at an estimated $1,326/year saved. Hard to find a home improvement with a faster payback than this.
The breakdown behind the number
Of that, about $1,063/year comes from reduced heating and $262/year from reduced cooling load through the ceiling. Union County beats 40% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 825 counties DOE places in zone 4, Union County ranks 531st. Against Illinois's own average of $1,642/year, Union County runs 19% below that.
Where these numbers come from
Union County's climate figures — 3,977 heating and 1,634 cooling degree days a year — are read from ANNA 2 NNE, IL US, 0.6 miles away, NOAA's nearest 1991-2020 normals station. By total degree days, Union County sits at the 42th percentile nationally. DOE also classifies Union County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
Already have some insulation?
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $193/year saved — roughly 11.8 years to break even. It is close - the payback only just fits a reasonable timeframe.
Getting it done in Union County
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 Union 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.