Coamo Municipio, PR Insulation Payback
Is attic insulation worth it in Coamo Municipio, PR?
Coamo 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. 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 $395 a year in heating and cooling — a payback around 4.3 years. That is a solid payback as home upgrades go.
The breakdown behind the number
Heating accounts for about $7/year of that and cooling about $388/year — Coamo Municipio needs both. Nationally, Coamo Municipio ranks in the 0th percentile for insulation savings potential. Compared only against its own climate zone, Coamo Municipio places 68th out of 81. Against Puerto Rico's own average of $660/year, Coamo Municipio runs 40% below that.
Coamo Municipio's actual weather, not a national average
The heating and cooling degree days behind this estimate — 27 HDD and 2,502 CDD (base 65°F, 1991-2020 normals) — come from AIBONITO 1 S, PR RQ, the nearest NOAA station with published normals, 6.4 miles from Coamo Municipio's center. Combined heating and cooling load puts Coamo Municipio in the 0th 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.
Already have some insulation?
A shallower starting point changes the math: with R-11 already down, only the gap to R-25 needs filling, at roughly $840 for an estimated $43/year saved (~19.5-year payback). Whether that is worth it depends on how long you plan to stay.
Quotes and materials for this job
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 Coamo Municipio job, not a quote. Expect at least a $600 minimum charge from most contractors.
Coamo Municipio's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Coamo Municipio'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.