San Juan Municipio, PR Insulation Payback
Is attic insulation worth it in San Juan Municipio, PR?
San Juan 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. Going from R-2 to the recommended R-30 costs roughly $1,680 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 2.2 years at an estimated $778/year saved. Few home upgrades pay back that quickly.
Where the savings come from
Heating accounts for about $0/year of that and cooling about $778/year — San Juan Municipio needs both. Nationally, San Juan Municipio ranks in the 4th percentile for insulation savings potential. Compared only against its own climate zone, San Juan Municipio places 22nd out of 81. Against Puerto Rico's own average of $660/year, San Juan Municipio runs 18% above that.
San Juan Municipio's actual weather, not a national average
San Juan Municipio's climate figures — 0 heating and 5,015 cooling degree days a year — are read from RIO PIEDRAS EXP STN, PR RQ, 2.4 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks San Juan Municipio 2330th nationally by total degree days — the 26th percentile. 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?
Already have a few inches up there? Topping R-11 up to R-25 runs about $840 for about $85/year saved — roughly 9.9 years to break even. Whether that is worth it depends on how long you plan to stay.
Next steps for a San Juan Municipio attic
Get more than one quote before committing. Attic access and any needed air sealing move the price around, and most contractors won't take a job below roughly $600 regardless of size - worth asking upfront given San Juan Municipio's estimated $778/year on the line.
San Juan Municipio's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed San Juan 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.