Dallas County, MO Insulation Payback
Dallas County attic insulation, by the numbers
DOE classifies Dallas County as climate zone 4, mixed-humid — real heating and real cooling seasons both, roughly balanced across the year. Its recommended attic R-value for bare joists is R-60. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-60 runs an estimated $3,480, and saves about $1,493 a year in heating and cooling — a payback around 2.3 years. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $1,293 a year on the heating side, $199 on cooling. By estimated insulation savings, Dallas County lands in the 53th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Dallas County comes in 185th by savings. Missouri averages $1,534/year across the counties tracked here; Dallas County comes in 3% lower.
Dallas County's actual weather, not a national average
The heating and cooling degree days behind this estimate — 4,836 HDD and 1,242 CDD (base 65°F, 1991-2020 normals) — come from BUFFALO 2N, MO US, the nearest NOAA station with published normals, 4.2 miles from Dallas County's center. That combined heating-and-cooling load ranks Dallas County 1478th nationally by total degree days — the 53th percentile. One local detail the R-value alone won't tell you: Dallas County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
If Dallas 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 $218/year — payback about 10.5 years. Call this borderline rather than a clear win.
Quotes and materials for this job
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 Dallas County's estimated $1,493/year on the line.
Where these figures come from
Dallas 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.