Can I use a dark roof if I add solar?

On the performance path, yes — adding PV capacity can offset a non-compliant roof. On the prescriptive path, no — the roof must meet its own minimums regardless of solar.

Do tile roofs need cool-roof rating?

In CZ 10–15 for steep-slope, yes. Most light and medium-light tiles meet aged SR ≥ 0.20 with high thermal emittance. Dark earth-tone tiles may require specifically rated SKUs.

What happens at inspection if my product isn't CRRC-rated?

Either rework to a compliant product, or switch to the performance path with a CBECC-Res model and a HERS rater. Both options cost more than choosing compliant from the start.

8 min read · updated 2026-05-19

Cool-roof compliance in Southern California: Title 24's prescriptive path explained

Southern California climate zones 8–15 require cool-roof products on most low-slope reroofs and many steep-slope replacements. Here's how SRI, CRRC ratings, and the prescriptive path actually work.

Which projects trigger cool-roof

Title 24 Part 6 §150.2 covers residential additions and alterations. Reroofs that replace more than 50% of the roof surface (the typical 'full reroof' scenario) trigger cool-roof compliance in most Southern California climate zones for low-slope roofs and in CZ 10–15 for steep-slope roofs. The CEC publishes the controlling standards CEC Title 24 Part 6 (cool-roof provisions).

Repairs under the 50% threshold and overlay-only work (where allowed by jurisdiction) typically do not trigger cool-roof — but the threshold is enforced strictly, and a 'partial reroof' that actually replaces 60% of the surface will be flagged at inspection.

SRI, reflectance, emittance — what the numbers mean

Three ratings matter: Solar Reflectance (SR, 0 to 1) — how much sunlight the roof reflects vs. absorbs; Thermal Emittance (E, 0 to 1) — how readily the roof releases absorbed heat; Solar Reflectance Index (SRI) — a composite metric (0 to 100+) that combines the two. All three are tested and rated by the CRRC Cool Roof Rating Council product database.

Title 24 prescriptive path requires minimums depending on slope and climate zone. For low-slope in most CZ: aged SR ≥ 0.63 and thermal emittance ≥ 0.75. For steep-slope CZ 10–15: aged SR ≥ 0.20 and thermal emittance ≥ 0.75. 'Aged' values matter — initial ratings are not what the code references.

Cool-roof options by material

Single-ply membranes (TPO, PVC): nearly all are cool-roof rated by default. TPO white has aged SR 0.68+ and dominates new low-slope work. PVC has similar ratings and better chemical resistance.

Tile (clay, concrete): light-colored tile typically meets steep-slope cool-roof requirements. Most major tile manufacturers list multiple SKUs with CRRC ratings on their websites.

Asphalt shingle: traditional shingles do not meet cool-roof minimums; specifically formulated cool-shingles (GAF Timberline Cool Series, CertainTeed Landmark Solaris) are available and meet steep-slope requirements.

Metal: standing-seam in light colors with cool-pigment coatings is typically compliant; bare metal or galvalume often is not (high reflectance but low emittance trips the composite SRI calculation).

Prescriptive vs. performance path

Prescriptive path: pick a CRRC-rated product that meets the minimums for your slope and climate zone. Document with the CRRC product ID at permit. Simple, fast, low risk.

Performance path: use whole-building energy modeling to demonstrate the project meets the energy budget despite a non-compliant roof. Requires a CEC-approved modeling tool (CBECC-Res), a HERS rater for verification, and offsetting upgrades elsewhere in the building. Usually only worth it on whole-house remodels with significant other envelope work.

What about rebates and resale

LADWP, SCE, and SoCalGas have run cool-roof rebate programs intermittently — confirm current funding before counting on it. The federal IRA Section 25C energy-efficient home improvement credit covers some cool-roof work as part of a broader envelope upgrade.

Resale impact is real but modest. Buyers in cooling-dominated CZ 10–15 increasingly ask about roof age and color; a 5–10 year old cool roof is a defensible value-add at appraisal.

Frequently asked

Can I use a dark roof if I add solar?: On the performance path, yes — adding PV capacity can offset a non-compliant roof. On the prescriptive path, no — the roof must meet its own minimums regardless of solar.
Do tile roofs need cool-roof rating?: In CZ 10–15 for steep-slope, yes. Most light and medium-light tiles meet aged SR ≥ 0.20 with high thermal emittance. Dark earth-tone tiles may require specifically rated SKUs.
What happens at inspection if my product isn't CRRC-rated?: Either rework to a compliant product, or switch to the performance path with a CBECC-Res model and a HERS rater. Both options cost more than choosing compliant from the start.

Sources we cited

1.CEC Title 24 Part 6 (cool-roof provisions) — California Energy Commission
2.Cool Roof Rating Council product database — CRRC

Referenced resources

Permit portals, fee bands, and code notes that back up the jurisdictions named in this article.

Related areas

Neighborhood guides that pair with this article — local code, lot patterns, and what we've actually built nearby.

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