Gurabo Municipio, PR Insulation Payback
Gurabo Municipio, PR: what topping up your attic actually costs
DOE classifies Gurabo Municipio as climate zone 1, hot-humid — summers that stay hot and humid while winters barely register on the energy bill. Its recommended attic R-value for bare joists is 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 $703 a year in heating and cooling — a payback around 2.4 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $0/year heating, $703/year cooling. Out of every 100 US counties tracked here, Gurabo Municipio's savings potential beats roughly 2 of them. Within zone 1 specifically, it ranks 44th of 81 counties by estimated savings. Puerto Rico averages $660/year across the counties tracked here; Gurabo Municipio comes in 7% higher.
The climate data behind this
NOAA's GURABO SUBSTN, PR RQ station, 1.2 miles from Gurabo Municipio, supplies the 0 HDD and 4,531 CDD this estimate runs on. By total degree days, Gurabo Municipio sits at the 12th percentile nationally. Gurabo Municipio falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
If the attic isn't bare
Already have a few inches up there? Topping R-11 up to R-25 runs about $840 for about $77/year saved — roughly 11 years to break even. This one is a genuine toss-up, not a clear yes.
Getting it done in Gurabo Municipio
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $1,680 figure above as a planning number for Gurabo Municipio, not a bid - contractors typically charge a $600 minimum regardless of job size.
Nothing here is a guess
Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-30 is the target here specifically.