Clark County, KY Insulation Payback
Clark County attic insulation, by the numbers
Clark County, Kentucky is zone 4 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-60. Going from R-2 to the recommended R-60 costs roughly $3,480 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 2.4 years at an estimated $1,432/year saved. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,269 a year on the heating side, $163 on cooling. By estimated insulation savings, Clark County lands in the 48th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Clark County comes in 308th by savings. Kentucky averages $1,385/year across the counties tracked here; Clark County comes in 3% higher.
Clark County's actual weather, not a national average
The heating and cooling degree days behind this estimate — 4,746 HDD and 1,016 CDD (base 65°F, 1991-2020 normals) — come from CRESSY, KY US, the nearest NOAA station with published normals, 11.4 miles from Clark County's center. That combined heating-and-cooling load ranks Clark County 1693rd nationally by total degree days — the 46th percentile. One local detail the R-value alone won't tell you: Clark County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
If Clark County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-49. That smaller top-up costs around $2,280 and saves an estimated $209/year — payback about 10.9 years. Call this borderline rather than a clear win.
Getting it done in Clark County
Get more than one quote before committing. Attic access and any needed air sealing move the price around, and most contractors won't take a job below roughly $600 regardless of size - worth asking upfront given Clark County's estimated $1,432/year on the line.
Where these figures come from
Clark County's R-60 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-60 is the target here specifically.