Madison County, IL Insulation Payback
Attic insulation payback for Madison County, IL
Madison County, Illinois 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. 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 2.3 years at an estimated $1,507/year saved. Hard to find a home improvement with a faster payback than this.
Where the savings come from
Of that, about $1,278/year comes from reduced heating and $229/year from reduced cooling load through the ceiling. Madison County beats 53% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 825 counties DOE places in zone 4, Madison County ranks 162nd. Against Illinois's own average of $1,642/year, Madison County runs 8% below that.
Madison County's actual weather, not a national average
Madison County's climate figures — 4,780 heating and 1,424 cooling degree days a year — are read from ALTON - MELVIN PRICE L&D, IL US, 13.7 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Madison County 1386th nationally by total degree days — the 56th percentile. DOE also classifies Madison County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
If the attic isn't bare
If Madison 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 $220/year — payback about 10.4 years. It is close - the payback only just fits a reasonable timeframe.
Quotes and materials for this job
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $3,480 as a starting estimate for a Madison County job, not a quote. Expect at least a $600 minimum charge from most contractors.
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.