Grayson County, TX Insulation Payback
Grayson County attic insulation, by the numbers
Grayson County sits in IECC climate zone 3 (Mixed-Humid) — a genuine mix of cold winters and humid summers, with neither one dominating the bill. For a currently uninsulated attic, DOE and ENERGY STAR recommend building 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 $1,084 a year in heating and cooling — a payback around 2.6 years. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $724 a year on the heating side, $360 on cooling. By estimated insulation savings, Grayson County lands in the 23th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Grayson County comes in 278th by savings. Texas averages $1,035/year across the counties tracked here; Grayson County comes in 5% higher.
Where these numbers come from
NOAA's SHERMAN, TX US station, 5.8 miles from Grayson County, supplies the 2,727 HDD and 2,261 CDD this estimate runs on. That combined heating-and-cooling load ranks Grayson County 2360th nationally by total degree days — the 25th percentile. One local detail the R-value alone won't tell you: Grayson County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $146/year saved — roughly 11.1 years to break even. Call this borderline rather than a clear win.
Getting it done in Grayson 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 Grayson County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Grayson 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.