Cameron County, TX Insulation Payback
Cameron County attic insulation, by the numbers
DOE classifies Cameron 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. For an attic around 1,000 square feet, closing the gap from R-2 to R-49 costs around $2,820 and saves an estimated $800 a year — payback in roughly 3.5 years. Topping up the attic pays for itself here.
The breakdown behind the number
Split it out and it's roughly $140 a year on the heating side, $660 on cooling. By estimated insulation savings, Cameron County lands in the 4th percentile nationally. Zone 2 alone covers 233 counties in this dataset, and Cameron County comes in 176th by savings. Texas averages $1,035/year across the counties tracked here; Cameron County comes in 23% lower.
Where these numbers come from
Cameron County's climate figures — 527 heating and 4,140 cooling degree days a year — are read from PORT ISABEL CAMERON AP, TX US, 9.3 miles away, NOAA's nearest 1991-2020 normals station. By total degree days, Cameron County sits at the 16th percentile nationally. One local detail the R-value alone won't tell you: Cameron County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
Already have some insulation?
If Cameron County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-38. That smaller top-up costs around $1,620 and saves an estimated $108/year — payback about 15 years. Call this borderline rather than a clear win.
Getting it done in Cameron County
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $2,820 figure above as a planning number for Cameron County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Cameron County's R-49 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-49 is the target here specifically.