Grant County, OK Insulation Payback
Is attic insulation worth it in Grant County, OK?
Grant 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. 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 $1,406 a year in heating and cooling — a payback around 2 years. Few home upgrades pay back that quickly.
The breakdown behind the number
Heating accounts for about $1,103/year of that and cooling about $303/year — Grant County needs both. Nationally, Grant County ranks in the 46th percentile for insulation savings potential. Compared only against its own climate zone, Grant County places 7th out of 690. Against Oklahoma's own average of $1,260/year, Grant County runs 12% above that.
Where these numbers come from
Grant County's climate figures — 4,157 heating and 1,902 cooling degree days a year — are read from MEDFORD 1SW MESONET, OK US, 2.4 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Grant County 1488th nationally by total degree days — the 53th percentile. Its moisture regime is classified humid, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
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 $189/year saved (~8.6-year payback). Whether that is worth it depends on how long you plan to stay.
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 Grant County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Grant County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Grant County's numbers, and where the cost assumptions come from. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.