Navarro County, TX Insulation Payback
Navarro County attic insulation, by the numbers
Navarro County, Texas is zone 3 under DOE's climate map (Hot-Humid), which means humid heat for much of the year, with cooling running far more than heating ever does. An uninsulated attic there should be built up to R-49. For an attic around 1,000 square feet, closing the gap from R-2 to R-49 costs around $2,820 and saves an estimated $978 a year — payback in roughly 2.9 years. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $536 a year on the heating side, $442 on cooling. By estimated insulation savings, Navarro County lands in the 15th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Navarro County comes in 521st by savings. Texas averages $1,035/year across the counties tracked here; Navarro County comes in 6% lower.
Navarro County's actual weather, not a national average
Navarro County's climate figures — 2,021 heating and 2,772 cooling degree days a year — are read from CORSICANA CAMPBELL FLD, TX US, 4.6 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Navarro County 2549th nationally by total degree days — the 19th percentile. One local detail the R-value alone won't tell you: Navarro County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
A shallower starting point changes the math: with R-11 already down, only the gap to R-38 needs filling, at roughly $1,620 for an estimated $132/year saved (~12.3-year payback). Call this borderline rather than a clear win.
Getting it done in Navarro County
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $2,820 figure above as a planning number for Navarro County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Navarro County's R-49 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-49 is the target here specifically.