Ellis County, TX Insulation Payback
Ellis County, TX: what topping up your attic actually costs
DOE classifies Ellis County as climate zone 3, hot-humid — humid heat for much of the year, with cooling running far more than heating ever does. Its recommended attic R-value for bare joists is 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 $1,050 a year in heating and cooling — a payback around 2.7 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $645/year heating, $405/year cooling. Out of every 100 US counties tracked here, Ellis County's savings potential beats roughly 20 of them. Within zone 3 specifically, it ranks 358th of 690 counties by estimated savings. Texas averages $1,035/year across the counties tracked here; Ellis County comes in 1% higher.
Where these numbers come from
Ellis County's climate figures — 2,431 heating and 2,543 cooling degree days a year — are read from WAXAHACHIE, TX US, 6.2 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Ellis County 2369th nationally by total degree days — the 25th percentile. Ellis County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
If the attic isn't bare
If Ellis County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-38. That smaller top-up costs around $1,620 and saves an estimated $141/year — payback about 11.5 years. This one is a genuine toss-up, not a clear yes.
Getting it done in Ellis County
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $2,820 as a starting estimate for a Ellis County job, not a quote. Expect at least a $600 minimum charge from most contractors.
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.