Nassau County, FL Insulation Payback
Nassau County attic insulation, by the numbers
Nassau County, Florida 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 3.7 years at an estimated $773/year saved. Topping up the attic pays for itself here.
Where the savings come from
Split it out and it's roughly $326 a year on the heating side, $447 on cooling. By estimated insulation savings, Nassau County lands in the 3th percentile nationally. Zone 2 alone covers 233 counties in this dataset, and Nassau County comes in 191st by savings. Florida averages $743/year across the counties tracked here; Nassau County comes in 4% higher.
The climate data behind this
NOAA's JACKSONVILLE, FL US station, 9.2 miles from Nassau County, supplies the 1,228 HDD and 2,803 CDD this estimate runs on. That combined heating-and-cooling load ranks Nassau County 3080th nationally by total degree days — the 3th percentile. One local detail the R-value alone won't tell you: Nassau County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
Already have some insulation?
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $104/year saved — roughly 15.6 years to break even. Call this borderline rather than a clear win.
Next steps for a Nassau County 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 Nassau County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Nassau 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.