Stewart County, TN Insulation Payback
Attic insulation payback for Stewart County, TN
Stewart County, Tennessee 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. 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 $1,275 a year — payback in roughly 2.7 years. Hard to find a home improvement with a faster payback than this.
Where the savings come from
Of that, about $1,028/year comes from reduced heating and $247/year from reduced cooling load through the ceiling. Stewart County beats 37% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 825 counties DOE places in zone 4, Stewart County ranks 632nd. Against Tennessee's own average of $1,258/year, Stewart County runs 1% above that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 3,845 HDD and 1,539 CDD (base 65°F, 1991-2020 normals) — come from DOVER 1 W, TN US, the nearest NOAA station with published normals, 3.9 miles from Stewart County's center. By total degree days, Stewart County sits at the 37th percentile nationally. DOE also classifies Stewart County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
Already have some insulation?
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 $186/year saved (~12.3-year payback). It is close - the payback only just fits a reasonable timeframe.
Getting it done in Stewart County
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 Stewart 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.