Harmon County, OK Insulation Payback
Harmon County, OK: what topping up your attic actually costs
Harmon County, Oklahoma is zone 3 under DOE's climate map (Mixed-Humid), which means a genuine mix of cold winters and humid summers, with neither one dominating the bill. An uninsulated attic there should be built up to R-49. Going from R-2 to the recommended R-49 costs roughly $2,820 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 2.3 years at an estimated $1,246/year saved. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $900/year heating, $346/year cooling. Out of every 100 US counties tracked here, Harmon County's savings potential beats roughly 34 of them. Within zone 3 specifically, it ranks 50th of 690 counties by estimated savings. Oklahoma averages $1,260/year across the counties tracked here; Harmon County comes in 1% lower.
Where these numbers come from
NOAA's HOLLIS 5E MESONET, OK US station, 4.2 miles from Harmon County, supplies the 3,392 HDD and 2,174 CDD this estimate runs on. That combined heating-and-cooling load ranks Harmon County 1859th nationally by total degree days — the 41th percentile. Harmon 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 $168/year saved (~9.7-year payback). This one is a genuine toss-up, not a clear yes.
Quotes and materials for this job
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 Harmon 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.