San Jacinto County, TX Insulation Payback
San Jacinto County, TX: what topping up your attic actually costs
DOE classifies San Jacinto County as climate zone 2, hot-humid — summers that stay hot and humid while winters barely register on the energy bill. Its recommended attic R-value for bare joists is 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 $881 a year in heating and cooling — a payback around 3.2 years. The math clears comfortably within a normal ownership horizon.
Where the savings come from
The estimated savings split roughly $490/year heating, $392/year cooling. Out of every 100 US counties tracked here, San Jacinto County's savings potential beats roughly 8 of them. Within zone 2 specifically, it ranks 72nd of 233 counties by estimated savings. Texas averages $1,035/year across the counties tracked here; San Jacinto County comes in 15% lower.
The climate data behind this
NOAA's CLEVELAND, TX US station, 15.3 miles from San Jacinto County, supplies the 1,845 HDD and 2,459 CDD this estimate runs on. Combined heating and cooling load puts San Jacinto County in the 7th percentile of this 3,162-county dataset. San Jacinto County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
Already have some insulation?
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $119/year saved — roughly 13.6 years to break even. This one is a genuine toss-up, not a clear yes.
Getting it done in San Jacinto 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 San Jacinto County's estimated $881/year on the line.
Nothing here is a guess
Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-49 is the target here specifically.