Color changes how hot a metal roof gets, but the number that decides it is not the name on the color chip. It is the tested three-year aged solar reflectance and the Solar Reflectance Index for the exact coating on the exact panel. In the Cool Roof Rating Council directory, factory-coated metal carries a three-year weathered SRI range of 20 to 90. Asphalt shingles run 14 to 34. That gap is the honest version of the claim that metal runs cooler than shingles, and it is the only version we will put in writing.
Reflectance, emittance and SRI are three different numbers
Solar reflectance is the fraction of the sun's energy a surface bounces back. Thermal emittance is how readily that surface radiates the heat it absorbed. Both are measured, both run 0 to 1, and neither alone tells you how hot the roof will get.
The Solar Reflectance Index combines them into a single calculated value under ASTM E1980, currently E1980-11(2019). The method works out the surface temperature the material would reach under a defined set of conditions, then scales that against two references: a standard white surface at SRI 100, and a standard black surface at SRI 0. The CRRC is careful to point out that SRI is a calculated value and is not the same thing as a measured solar reflectance, which is exactly why a very reflective bare metal roof can score badly.
The CRRC publishes both initial and three-year aged values. Use the aged number. A roof's first summer is not the number you live with, and where Florida code engages with reflectance at all, it is written around three-year aged values.
What the CRRC directory shows for metal against shingles
These are the three-year weathered SRI ranges the CRRC publishes for each product family, covering every rated product of that type regardless of color.
| Roof product type | Three-year weathered SRI range |
|---|---|
| Clay and concrete tile | 4 to 91 |
| Asphalt shingles | 14 to 34 |
| Factory-coated metal | 20 to 90 |
Read that table honestly. Metal's ceiling is far above asphalt's: a light factory-applied coating can land near 90, and no asphalt shingle in the directory gets past 34. But metal's floor is lower than most people expect, and a dark factory-coated panel at the bottom of that 20 to 90 band is not doing much better than a mid-range shingle.
Buying metal does not buy you a cool roof. Buying a light, high-emittance factory coating does. Those ranges are a fair way to compare material families and a poor way to argue about any one product, so for a specific panel and color look it up in the CRRC directory and read its own aged values.
Where Florida code requires a cool roof, and where it does not
The governing document is the Florida Building Code, Energy Conservation, 8th Edition (2023), effective December 31, 2023. It made the cool roof requirement stricter, and it did so in one narrow place.
Section C303.1.5 requires low-sloped roofs directly above cooled conditioned space in climate zone 1A to comply with one or more of the options in Table C402.3. For zone 1A that table sets a three-year aged solar reflectance of 0.63 together with a three-year aged thermal emittance of 0.75, or a three-year aged SRI of 75. The generic zone 1 through 3 options are lower: 0.55 aged reflectance with 0.75 aged emittance, or an aged SRI of 64.
Two boundaries decide whether any of that applies to your building.
The first is the county. Exactly seven Florida counties are climate zone 1A: Broward, Collier, Hendry, Lee, Miami-Dade, Monroe and Palm Beach. The other sixty are zone 2A. Several roofing blogs also list Sarasota, Charlotte, St. Lucie, Martin, Highlands or Indian River as 1A. They are not, and Hendry, which is inland and easy to overlook, is the one most often left off the correct list. Get the county right before quoting a threshold at anyone.
The second is slope. C303.1.5 reaches low-sloped roofs over cooled conditioned space. There is no prescriptive steep-slope cool roof mandate in Florida's commercial provisions, and there is none in the residential provisions either. A standing seam roof on a 5:12 house in Naples is not required by code to hit any reflectance number at all.
Bare Galvalume looks like a cool roof and is not one
This is the clearest reason SRI exists as a separate number. In the Oak Ridge National Laboratory field study by Kriner, Miller and Desjarlais, the measured pairs came out like this:
| Surface | Solar reflectance | Thermal emittance |
|---|---|---|
| Unpainted 55% Al-Zn coated steel | 0.69 | 0.06 |
| Unpainted galvanized steel | 0.66 | 0.06 |
| White-painted PVDF | 0.64 | 0.83 |
| Off-white polyester | 0.62 | 0.83 |
| Asphalt shingle | 0.09 | 0.91 |
| Built-up roof | 0.05 | 0.90 |
Read the first and third rows side by side. Bare Galvalume reflects more sunlight than the white painted panel does. It also radiates almost none of the heat it does absorb, because its emittance is 0.06 against the painted panel's 0.83. Run both through ASTM E1980 and the painted panel wins decisively, because SRI counts both halves. Reflectance alone is the wrong number to sell on, and it is the number bare metal happens to be good at.
Bare metal also does not hold the reflectance it starts with. In the same study the unpainted galvanized panel began with a mirror-like specular finish, and within thirty days its reflectance had fallen from 0.66 to 0.32. Across the low-slope metal roofs in that test the average drop over the study period was about 7 percent. The galvanized panel lost half its reflectance in a month. One caution on that data set: it was published in 2001, and its dark-color figures predate modern cool-pigment chemistry, so do not treat them as a description of what a dark PVDF color does today. What is actually available on each of our panels is on the color and coatings page.
The credit that does exist: get the product CRRC listed
Florida residential energy compliance is normally run through the performance path in EnergyGauge, the state-approved software behind the R405 and R406 calculations. That software allows a cool roof option where the roof to be installed has a tested solar reflectance evaluated under ASTM E903, ASTM C1549, ASTM E1918 or CRRC Method #1, with the testing performed by an approved independent laboratory.
That is the one genuinely useful reason to care about CRRC listing on a Florida house. A listed panel and color with documented three-year aged values can be entered into the calculation and earn real credit toward compliance. An unlisted product cannot, however light it looks and however good the brochure copy is. If a cool roof credit is part of how a house passes energy code, ask for the CRRC product ID before the panel is ordered, not after the model is submitted. On commercial work in the seven zone 1A counties the same logic applies with more force, because there the aged values are a threshold rather than a credit.
The credit that does not exist
There is no federal tax credit and no Florida tax credit, rebate or sales tax exemption for putting a metal roof on a house. We state that plainly, because a great deal of roofing copy still implies otherwise.
Roofing was removed from the Section 25C energy efficient home improvement credit for property placed in service after December 31, 2022. The IRS published a formal correction to the 2023 Form 1040 instructions striking the line about a metal or asphalt roof with pigmented coatings or cooling granules. Section 25C then terminated outright for property placed in service after December 31, 2025. Two independent reasons, either one fatal.
Florida's home hardening sales tax break does not reach roofing either. Under Department of Revenue TIP 26A01-09, the qualifying products are impact-resistant doors, impact-resistant garage doors and impact-resistant windows. Roofs appear nowhere in it. It is refund-only rather than claimed at the register, limited to a homesteaded site-built dwelling with a just value of $700,000 or less, and the total refund may not exceed $500.
One more loop worth closing: there is no such thing as an ENERGY STAR rated metal roof. The EPA ended that certification program for roofing products on June 1, 2022, and nothing has been certified to it since. CRRC is the body to ask about.
How we would pick a color for a Florida house
- Settle the substrate and the finish system first. Aluminum or Galvalume steel, PVDF or SMP or mill finish. That decision is driven by distance to salt water and by the warranty terms that come with each combination, and it constrains which colors exist at all.
- Ask for the CRRC product ID and the three-year aged solar reflectance, thermal emittance and SRI for the specific color, not for the coating family.
- If the building is low-slope over cooled conditioned space in Broward, Collier, Hendry, Lee, Miami-Dade, Monroe or Palm Beach, check those numbers against Table C402.3 before the order goes in.
- If the house is passing energy code on the performance path, hand the CRRC values to whoever is running the R405 or R406 calculation while the model can still be changed.
- Then argue about how it looks. A dark roof on a Florida house is a legitimate choice. It is simply not a cool roof, and the aged SRI says so.
What we will not do is hand you a dollar figure or a percentage off your power bill. The savings numbers circulating on roofing sites are not traceable to any specific product, let alone to ours, and a reflectance value you can verify in a public directory is worth more than a savings claim you cannot. The cost comparison we are willing to make is the whole-life one, in our piece on metal against shingles over the life of the roof, and if appearance after a storm is also on your mind, the companion piece on whether hail dents a metal roof is the candid version of that question.
When you have a color in mind, price the exact panel, gauge and finish through Instant Metal Quote, or send the project to our sales desk and we will pull the CRRC values for that color before you commit to it.
