Johnson County, AR Insulation Payback
Is attic insulation worth it in Johnson County, AR?
Johnson County, Arkansas is zone 3 under DOE's climate map (Mixed-Humid), which means heating load in winter and cooling load in summer, both worth taking seriously here. 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 $1,228 a year in heating and cooling — a payback around 2.3 years. Few home upgrades pay back that quickly.
The breakdown behind the number
Heating accounts for about $949/year of that and cooling about $279/year — Johnson County needs both. Nationally, Johnson County ranks in the 33th percentile for insulation savings potential. Compared only against its own climate zone, Johnson County places 68th out of 690. Against Arkansas's own average of $1,185/year, Johnson County runs 4% above that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 3,577 HDD and 1,753 CDD (base 65°F, 1991-2020 normals) — come from CLARKSVILLE 6 NE, AR US, the nearest NOAA station with published normals, 4.5 miles from Johnson County's center. That combined heating-and-cooling load ranks Johnson County 2041st nationally by total degree days — the 35th 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
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $165/year saved — roughly 9.8 years to break even. Whether that is worth it depends on how long you plan to stay.
Quotes and materials for this job
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 Johnson County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Johnson County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Johnson 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.