Duval County, TX Insulation Payback
Attic insulation payback for Duval County, TX
Duval County sits in IECC climate zone 2 (Hot-Humid) — humid heat for much of the year, with cooling running far more than heating ever does. For a currently uninsulated attic, DOE and ENERGY STAR recommend building 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 $868 a year in heating and cooling — a payback around 3.2 years. Worth doing on the numbers alone.
Where the savings come from
Of that, about $283/year comes from reduced heating and $585/year from reduced cooling load through the ceiling. Duval County beats 8% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 233 counties DOE places in zone 2, Duval County ranks 88th. Against Texas's own average of $1,035/year, Duval County runs 16% below that.
The climate data behind this
The heating and cooling degree days behind this estimate — 1,067 HDD and 3,672 CDD (base 65°F, 1991-2020 normals) — come from BENAVIDES 2, TX US, the nearest NOAA station with published normals, 7.7 miles from Duval County's center. Combined heating and cooling load puts Duval County in the 18th percentile of this 3,162-county dataset. DOE also classifies Duval County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
If the attic isn't bare
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 $117/year saved (~13.9-year payback). It is close - the payback only just fits a reasonable timeframe.
Next steps for a Duval County attic
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 Duval County's estimated $868/year on the line.
More on how this was built
Nothing here is a guess: the methodology guide names the DOE climate map and NOAA station data behind every number on this page. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.