Coal County, OK Insulation Payback
Coal County, OK: what topping up your attic actually costs
DOE classifies Coal County as climate zone 3, mixed-humid — real heating and real cooling seasons both, roughly balanced across the year. Its recommended attic R-value for bare joists is 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 $1,193 a year — payback in roughly 2.4 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $885/year heating, $308/year cooling. Out of every 100 US counties tracked here, Coal County's savings potential beats roughly 31 of them. Within zone 3 specifically, it ranks 104th of 690 counties by estimated savings. Oklahoma averages $1,260/year across the counties tracked here; Coal County comes in 5% lower.
The climate data behind this
Coal County's climate figures — 3,334 heating and 1,933 cooling degree days a year — are read from CENTRAHOMA 2 ESE, OK US, 1.9 miles away, NOAA's nearest 1991-2020 normals station. By total degree days, Coal County sits at the 33th percentile nationally. Coal County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
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 $161/year saved (~10.1-year payback). This one is a genuine toss-up, not a clear yes.
Next steps for a Coal County attic
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 Coal 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.