Lafayette Parish, LA Insulation Payback
Lafayette Parish attic insulation, by the numbers
Lafayette Parish, Louisiana is zone 2 under DOE's climate map (Hot-Humid), which means humid heat for much of the year, with cooling running far more than heating ever does. An uninsulated attic there should be built up to 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 $851 a year — payback in roughly 3.3 years. Topping up the attic pays for itself here.
Where the savings come from
Split it out and it's roughly $418 a year on the heating side, $433 on cooling. By estimated insulation savings, Lafayette Parish lands in the 7th percentile nationally. Zone 2 alone covers 233 counties in this dataset, and Lafayette Parish comes in 112th by savings. Louisiana averages $906/year across the counties tracked here; Lafayette Parish comes in 6% lower.
The climate data behind this
The heating and cooling degree days behind this estimate — 1,575 HDD and 2,716 CDD (base 65°F, 1991-2020 normals) — come from LAFAYETTE, LA US, the nearest NOAA station with published normals, 0.9 miles from Lafayette Parish's center. Combined heating and cooling load puts Lafayette Parish in the 6th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Lafayette Parish sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $115/year saved — roughly 14.1 years to break even. Call this borderline rather than a clear win.
Getting it done in Lafayette Parish
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 Lafayette Parish, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Lafayette Parish'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.