CRRC Rated Roof Products
CRRC-rated roof products are roofing materials independently tested by the Cool Roof Rating Council (CRRC) for solar reflectance and thermal emittance — the two properties that determine how cool and energy-efficient a roof is.
What is a CRRC rating?
A CRRC rating is an independent, third-party measurement of a roof product’s solar reflectance and thermal emittance, published in the Cool Roof Rating Council’s Rated Products Directory. The CRRC — a nonprofit founded in 1998 and headquartered in Portland, Oregon — develops the test methods and lists the results, but it does not set pass/fail limits; building codes and programs do. Its standard is ANSI/CRRC S100.
The three numbers that define a cool roof
Solar reflectance and thermal emittance together determine a roof’s “coolness,” and the Solar Reflectance Index (SRI) rolls them into a single figure:
| Property | Scale | What it means | Test method |
|---|---|---|---|
| Solar reflectance (SR) | 0 to 1 | Share of the sun’s energy the surface reflects rather than absorbs. Higher is cooler. | ASTM C1549 / E903 |
| Thermal emittance (TE) | 0 to 1 | How efficiently the surface sheds the heat it does absorb. Higher is cooler. | ASTM C1371 |
| Solar Reflectance Index (SRI) | 0 = std. black, 100 = std. white | A single number combining SR and TE; can exceed 100 or fall below 0. | ASTM E1980 |
Why CRRC ratings matter
- Energy efficiency: a reflective roof absorbs less heat, cutting cooling demand — by EPA estimates a reflective roof can stay over 50°F cooler than a conventional one and reduce peak cooling demand by 11–27%.
- Urban heat island: cool roofs help lower the elevated temperatures of built-up areas.
- Code & program compliance: CRRC ratings are the basis for California Title 24 cool-roof credit and LEED’s Heat Island Reduction credit.
- Resale & sustainability: verified energy performance is a documented selling point and reduces a home’s carbon footprint.
Interlock’s CRRC-rated aluminum colors
Every Interlock® aluminum profile is finished with the Alunar® Coating System, which uses Cool Roof infrared-reflective pigments. The colors below are independently rated under Interlock Roofing Ltd. in the CRRC Rated Products Directory — each value is the council’s measured initial and 3-year-aged figure. Aged Copper is the top performer at SRI 49.
| Color | CRRC Product ID | Solar reflectance | Thermal emittance | SRI |
|---|---|---|---|---|
| Aged Copper | 1008-0001 | 0.44 / 0.44 | 0.85 / 0.86 | 49 / 49 |
| Tile Red | 1008-0012 | 0.32 / 0.32 | 0.83 / 0.86 | 31 / 33 |
| Royal Blue | 1008-0009 | 0.25 / 0.29 | 0.83 / 0.87 | 22 / 29 |
| Black | 1008-0003 | 0.25 / 0.25 | 0.83 / 0.83 | 22 / 22 |
| Charcoal | 1008-0005 | 0.25 / 0.25 | 0.83 / 0.83 | 22 / 22 |
| Deep Charcoal | 1008-0016 | 0.25 / 0.25 | 0.83 / 0.83 | 22 / 22 |
| Colonial Brown | 1008-0015 | 0.25 / 0.25 | 0.83 / 0.83 | 22 / 22 |
| Tudor Brown | 1008-0014 | 0.25 / 0.25 | 0.83 / 0.83 | 22 / 22 |
| Hunter Green | 1008-0006 | 0.25 / pending | 0.83 / pending | 22 / pending |
Values shown as initial / 3-year aged. “Pending” means the 3-year field-aged value is still being measured. Interlock also lists a steel “Future Roof” line; verify the current rating for a specific color and profile in the CRRC Directory.
Is a metal roof automatically a cool roof?
No — and this is the key point for metal roofing. Bare, unpainted metal reflects sunlight well but has very low thermal emittance, so it holds heat and scores poorly on SRI. What turns metal into a genuine cool roof is the coating: Interlock’s Alunar® finish delivers high thermal emittance and uses infrared-reflective “cool color” pigments, so an Interlock roof can look dark yet reflect much of the sun’s heat and shed what it absorbs.
A Cool Roof — What Is That?
Highlights from a conversation with Jeffrey Steuben, Executive Director, and Sarah Schneider, Deputy Director, of the Cool Roof Rating Council:
The CRRC is a nonprofit organization created in 1998 to implement a third-party product rating system for roofing products — a way to help homeowners, policy makers and builders understand how they can increase the energy efficiency of a house just by the type of roof on it.
At its most simple, a cool roof is a roof that can reflect heat energy from the sun and re-emit energy that’s absorbed back into the environment. People might most easily think of a bright white roof, but there have been developments in “cool colors” that look the same as a standard color while being more reflective in the infrared spectrum. There are metal roofs on the market in a whole host of colors that use reflective pigments to help reflect solar radiation away and keep the building cooler.
Homeowners should think about cool roofs because they can have a really positive impact on energy bills and on comfort — especially during hot summer months, and even in homes without air conditioning. There’s often one opportunity in a homeowner’s lifetime to replace a roof, so it pays to be thoughtful about the long-term benefits: lower utility bills, a more comfortable interior, and a contribution toward reducing energy demand, reliance on fossil fuels and greenhouse gas emissions.
CRRC vs. ENERGY STAR vs. Title 24 vs. LEED
These programs are often confused. Only the CRRC actually rates the product; the others reference those ratings — and the ENERGY STAR roofing label no longer exists.
| Program | What it is | Roofing status (2026) | Role |
|---|---|---|---|
| Cool Roof Rating Council (CRRC) | Independent nonprofit that measures and lists solar reflectance, thermal emittance, and SRI. | Active — the cool-roof rating authority | Reports initial and 3-year aged SR, TE, and SRI |
| ENERGY STAR (roofing) | EPA labeling program. | Discontinued in 2022 — no roofing certification exists today | Use CRRC ratings instead |
| California Title 24 | State building energy code (current cycle effective Jan 1, 2026). | Mandatory in California | Requires a CRRC label with emittance + aged SR for compliance credit |
| LEED v4 / v4.1 | Voluntary green-building rating system. | Voluntary credit | Heat Island Reduction credit uses SRI (e.g., low-slope initial SRI ≥ 82) |
Cool-roofing terms, defined
- Solar reflectance
- The fraction of solar energy a surface reflects rather than absorbs, on a 0-to-1 scale (ASTM C1549/E903).
- Thermal emittance
- How efficiently a surface releases absorbed heat as radiation, on a 0-to-1 scale (ASTM C1371).
- Solar Reflectance Index (SRI)
- A composite of solar reflectance and thermal emittance; standard black = 0 and standard white = 100 (ASTM E1980).
- Cool roof
- A roof that reflects more sunlight and releases absorbed heat efficiently, staying cooler than a conventional roof.
- Aged reflectance
- Solar reflectance measured after three years of outdoor weathering, reflecting real-world performance.
CRRC Rated Roofing — Frequently Asked Questions
What does it mean for a roof product to be CRRC-rated?
It means the product’s solar reflectance and thermal emittance have been independently measured under the Cool Roof Rating Council’s program and published in the CRRC Rated Products Directory. The CRRC lists both initial (new) and 3-year aged values; it measures the properties but does not set pass/fail thresholds — building codes do that.
What is the difference between solar reflectance and thermal emittance?
Solar reflectance is how much of the sun’s energy a surface reflects instead of absorbing (0 to 1). Thermal emittance is how efficiently the surface releases the heat it does absorb (0 to 1). A true cool roof needs both to be high. SRI combines the two into a single index.
What is a good SRI for a roof?
SRI runs from 0 (a standard black surface) to 100 (a standard white surface) and can exceed 100. For reference, LEED’s Heat Island Reduction credit calls for an initial SRI of about 82 for low-slope roofs and about 39 for steep-slope roofs. Cool-colored metal roofs use infrared-reflective pigments to raise SRI while keeping a dark appearance.
Are Interlock metal roofs CRRC-rated?
Yes. Interlock’s Alunar®-coated aluminum roofing is rated by the Cool Roof Rating Council. The Alunar® coating uses Cool Roof infrared-reflective pigments, and the rated colors with their measured values are listed below and in the CRRC Rated Products Directory.
Is a metal roof automatically a cool roof?
No. Bare, unpainted metal reflects sunlight well but has very low thermal emittance, so it stays hot and scores poorly on SRI. A factory-applied coating like Alunar® gives the metal high thermal emittance — which is what makes a coated metal roof a genuine cool roof.
Does a CRRC rating help with California Title 24?
Yes. California Title 24 requires roofing products taking cool-roof compliance credit to carry a CRRC label showing thermal emittance and the initial and 3-year aged solar reflectance (or a CRRC Rapid Rating). A CRRC-rated product is what makes that compliance path available.
Is there an ENERGY STAR rating for roofing?
No. The ENERGY STAR roof products specification was discontinued in 2022 because building codes had surpassed its thresholds, so there is no current ENERGY STAR roofing certification to claim. The Cool Roof Rating Council is the recognized authority for roof solar-reflectance and thermal-emittance ratings.
What is the difference between initial and aged CRRC values?
Initial values are measured on a new, clean product. Aged values are measured after three years of real outdoor exposure at CRRC test farms in three climate zones, capturing the effects of weathering and soiling. CRRC may also list interim laboratory-aged "Rapid Ratings" (per ASTM D7897) until field-aged values are available.
Do cool roofs make sense in cold climates?
The reflective benefit is largest in hot and sunny climates, where it can cut peak cooling demand significantly. In cold climates the heating-season trade-off is small relative to the cooling-season savings for most homes, and Interlock’s interlocking aluminum panels are engineered to perform across the full North American climate range regardless of color.
CRRC Rated Products Directory
For the most current ratings, search the official CRRC Rated Products Directory. Looking for the underlying technology? See the Alunar® Coating System, browse metal roof colors, or review our testing reports.
*CRRC Rapid Ratings are interim laboratory-aged values (per ASTM D7897) that simulate weathering. They are replaced by measured three-year aged values once field weathering is complete; SRI calculated from Rapid Ratings may change when the aged rating replaces the interim value.