St. Landry Parish, LA Insulation Payback
Is attic insulation worth it in St. Landry Parish, LA?
St. Landry Parish sits in IECC climate zone 2 (Hot-Humid) — long, muggy summers and mild winters, where cooling dominates the energy bill. For a currently uninsulated attic, DOE and ENERGY STAR recommend building 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 $819 a year — payback in roughly 3.4 years. That is a solid payback as home upgrades go.
Heating vs. cooling in St. Landry Parish
Heating accounts for about $389/year of that and cooling about $430/year — St. Landry Parish needs both. Nationally, St. Landry Parish ranks in the 5th percentile for insulation savings potential. Compared only against its own climate zone, St. Landry Parish places 153rd out of 233. Against Louisiana's own average of $906/year, St. Landry Parish runs 10% below that.
The climate data behind this
The heating and cooling degree days behind this estimate — 1,467 HDD and 2,698 CDD (base 65°F, 1991-2020 normals) — come from GRAND COTEAU, LA US, the nearest NOAA station with published normals, 11.9 miles from St. Landry Parish's center. Combined heating and cooling load puts St. Landry Parish in the 4th percentile of this 3,162-county dataset. Its moisture regime is classified humid, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
The smaller top-up scenario
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 $110/year saved (~14.7-year payback). Whether that is worth it depends on how long you plan to stay.
Next steps for a St. Landry Parish attic
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 St. Landry Parish job, not a quote. Expect at least a $600 minimum charge from most contractors.
St. Landry Parish's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed St. Landry Parish's numbers, and where the cost assumptions come from. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.