Cabo Rojo Municipio, PR Insulation Payback
Cabo Rojo Municipio attic insulation, by the numbers
Cabo Rojo Municipio sits in IECC climate zone 1 (Hot-Humid) — summers that stay hot and humid while winters barely register on the energy bill. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to R-30. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-30 runs an estimated $1,680, and saves about $751 a year in heating and cooling — a payback around 2.2 years. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $0 a year on the heating side, $751 on cooling. By estimated insulation savings, Cabo Rojo Municipio lands in the 3th percentile nationally. Zone 1 alone covers 81 counties in this dataset, and Cabo Rojo Municipio comes in 30th by savings. Puerto Rico averages $660/year across the counties tracked here; Cabo Rojo Municipio comes in 14% higher.
Where these numbers come from
The heating and cooling degree days behind this estimate — 0 HDD and 4,845 CDD (base 65°F, 1991-2020 normals) — come from LAJAS SUBSTN, PR RQ, the nearest NOAA station with published normals, 7.6 miles from Cabo Rojo Municipio's center. That combined heating-and-cooling load ranks Cabo Rojo Municipio 2494th nationally by total degree days — the 21th percentile. One local detail the R-value alone won't tell you: Cabo Rojo Municipio sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
If Cabo Rojo 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 $82/year — payback about 10.2 years. Call this borderline rather than a clear win.
Next steps for a Cabo Rojo Municipio attic
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 Cabo Rojo Municipio job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Cabo Rojo 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.