Assumption Parish, LA Insulation Payback
Assumption Parish, LA: what topping up your attic actually costs
Assumption 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. Going from R-2 to the recommended R-49 costs roughly $2,820 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 3.4 years at an estimated $836/year saved. The math clears comfortably within a normal ownership horizon.
Heating vs. cooling in Assumption Parish
The estimated savings split roughly $405/year heating, $431/year cooling. Out of every 100 US counties tracked here, Assumption Parish's savings potential beats roughly 6 of them. Within zone 2 specifically, it ranks 137th of 233 counties by estimated savings. Louisiana averages $906/year across the counties tracked here; Assumption Parish comes in 8% lower.
The climate data behind this
Assumption Parish's climate figures — 1,526 heating and 2,705 cooling degree days a year — are read from DONALDSONVILLE 4 SW, LA US, 11.9 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Assumption Parish 3004th nationally by total degree days — the 5th percentile. Assumption Parish 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 $113/year saved — roughly 14.4 years to break even. This one is a genuine toss-up, not a clear yes.
Quotes and materials for this job
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 Assumption Parish, not a bid - contractors typically charge a $600 minimum regardless of job size.
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.