San Lorenzo Municipio, PR Insulation Payback
San Lorenzo Municipio attic insulation, by the numbers
San Lorenzo Municipio, Puerto Rico is zone 1 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-30. For an attic around 1,000 square feet, closing the gap from R-2 to R-30 costs around $1,680 and saves an estimated $701 a year — payback in roughly 2.4 years. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $0 a year on the heating side, $700 on cooling. By estimated insulation savings, San Lorenzo Municipio lands in the 2th percentile nationally. Zone 1 alone covers 81 counties in this dataset, and San Lorenzo Municipio comes in 48th by savings. Puerto Rico averages $660/year across the counties tracked here; San Lorenzo Municipio comes in 6% higher.
San Lorenzo Municipio's actual weather, not a national average
The heating and cooling degree days behind this estimate — 1 HDD and 4,516 CDD (base 65°F, 1991-2020 normals) — come from JUNCOS 1 SE, PR RQ, the nearest NOAA station with published normals, 6.9 miles from San Lorenzo Municipio's center. That combined heating-and-cooling load ranks San Lorenzo Municipio 2793rd nationally by total degree days — the 12th percentile. One local detail the R-value alone won't tell you: San Lorenzo Municipio sits in moisture regime A (humid), which can affect the vapor-barrier choice.
Already have some insulation?
If San Lorenzo Municipio's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-25. That smaller top-up costs around $840 and saves an estimated $76/year — payback about 11 years. Call this borderline rather than a clear win.
Getting it done in San Lorenzo Municipio
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $1,680 as a starting estimate for a San Lorenzo Municipio job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
San Lorenzo Municipio's R-30 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-30 is the target here specifically.