Lafourche Parish, LA Insulation Payback
Lafourche Parish attic insulation, by the numbers
Lafourche Parish, Louisiana is zone 2 under DOE's climate map (Hot-Humid), which means long, muggy summers and mild winters, where cooling dominates the energy bill. An uninsulated attic there should be built 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 $796 a year in heating and cooling — a payback around 3.5 years. Topping up the attic pays for itself here.
The breakdown behind the number
Split it out and it's roughly $336 a year on the heating side, $460 on cooling. By estimated insulation savings, Lafourche Parish lands in the 4th percentile nationally. Zone 2 alone covers 233 counties in this dataset, and Lafourche Parish comes in 178th by savings. Louisiana averages $906/year across the counties tracked here; Lafourche Parish comes in 12% lower.
Lafourche Parish's actual weather, not a national average
Lafourche Parish's climate figures — 1,267 heating and 2,886 cooling degree days a year — are read from GALLIANO, LA US, 5.6 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Lafourche Parish 3042nd nationally by total degree days — the 4th percentile. One local detail the R-value alone won't tell you: Lafourche 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 $107/year saved — roughly 15.1 years to break even. Call this borderline rather than a clear win.
Quotes and materials for this job
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $2,820 as a starting estimate for a Lafourche Parish job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Lafourche 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.