Mills County, TX Insulation Payback
Mills County, TX: what topping up your attic actually costs
Mills County, Texas is zone 3 under DOE's climate map (Hot-Humid), which means long, muggy summers and mild winters, where cooling dominates the energy bill. An uninsulated attic there should be built up to R-49. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-49 runs an estimated $2,820, and saves about $993 a year in heating and cooling — a payback around 2.8 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $629/year heating, $364/year cooling. Out of every 100 US counties tracked here, Mills County's savings potential beats roughly 16 of them. Within zone 3 specifically, it ranks 485th of 690 counties by estimated savings. Texas averages $1,035/year across the counties tracked here; Mills County comes in 4% lower.
Mills County's actual weather, not a national average
Mills County's climate figures — 2,372 heating and 2,281 cooling degree days a year — are read from GOLDTHWAITE 1 WSW, TX US, 3.8 miles away, NOAA's nearest 1991-2020 normals station. By total degree days, Mills County sits at the 15th percentile nationally. Mills County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
Already have some insulation?
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 $134/year saved (~12.1-year payback). This one is a genuine toss-up, not a clear yes.
Getting it done in Mills 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 Mills County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Nothing here is a guess
Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-49 is the target here specifically.