Title 24 Cool-Roof Rules for Re-Roofs in Los Angeles
The Valley is Climate Zone 9 in every ZIP code we serve, which puts most steep-slope re-roofs inside the state cool-roof rule, and the City of Los Angeles adds its own. Here is exactly what applies, with the section numbers.
Under the 2025 California Energy Code, Section 150.2(b)1I, replacing more than 50 percent of a single-family roof in Climate Zone 9 (all of the San Fernando Valley) triggers the cool-roof rule: steep-slope roofs need an aged solar reflectance of 0.20 and thermal emittance of 0.75, or SRI 16; low-slope roofs need 0.63 and 0.75, or SRI 75.
Within the City of Los Angeles, LADBS adds its own line to every residential re-roof permit: a replacement over 50 percent of the roof area must use a product labeled and certified by the Cool Roof Rating Council. Exceptions exist for insulated attics, radiant barriers, attics with no ducts, deck insulation and heavy roof assemblies; in practice almost every shingle we install is a rated cool-roof color anyway.
"Title 24" is shorthand for the California Building Standards Code; Part 6 is the Building Energy Efficiency Standards, written by the California Energy Commission. The 2025 edition took effect on 1 January 2026, and it is the version that applies to any re-roof permitted now. Cool-roof requirements have been part of it for years; what changes between editions is which climate zones and which roof slopes they cover.
Which climate zone is the Valley?
Climate Zone 9. The Energy Commission assigns zones by ZIP code, and every ZIP we serve, 91401, 91403, 91405, 91406, 91411 and 91423 (Sherman Oaks and Van Nuys), 91604 (Studio City), 91316 and 91436 (Encino), 91501–91506 (Burbank), 91601, 91602, 91605 and 91606 (North Hollywood and Toluca Lake), 91607 (Valley Village), 91356 and 91335 (Tarzana), 91364 and 91367 (Woodland Hills), is listed as Zone 9 in the Commission's ZIP-code table. That matters because the steep-slope rule covers Zones 4 and 8 through 15, and the low-slope rule covers Zones 4 and 6 through 15; the Valley is inside both.
The state rule: Section 150.2(b)1I
Section 150.2 governs additions and alterations to existing single-family buildings. Subsection (b)1I covers roofs: when more than 50 percent of the roof is being replaced, including a new layer over the existing surface, the new roofing products must meet one of two sets of numbers.
| Roof slope | Climate zones | Aged solar reflectance | Thermal emittance | Or SRI |
|---|---|---|---|---|
| Steep slope (more than 2:12) | 4 and 8–15 (Valley = 9) | 0.20 | 0.75 | 16 |
| Low slope (2:12 or less) | 4 and 6–15 (Valley = 9) | 0.63 | 0.75 | 75 |
"Aged" reflectance means the value after three years of weathering, as tested by the Cool Roof Rating Council, not the shiny-new number. SRI, the Solar Reflectance Index, combines reflectance and emittance into one figure.
The exceptions
For steep-slope roofs, any one of the following is treated as equivalent to the reflectance requirement: a ceiling assembly with a U-factor of 0.025 or lower, or at least R-38 ceiling insulation; a qualifying radiant barrier in the attic (not directly above spaced sheathing); in Climate Zones 2, 4, 9, 10, 12 and 14, a building with no ducts in the attic; or R-2 or greater continuous insulation above or below the roof deck. Two further exceptions apply to both slopes: roof area covered by building-integrated solar, and roof assemblies weighing 25 lb/sq ft or more, which covers most concrete and clay tile. For low-slope roofs the reflectance can also be met with roof-deck insulation per the code's Table 150.2-E.
The City of Los Angeles rule
Inside the City of Los Angeles, which includes Sherman Oaks, Studio City, Encino, Van Nuys, North Hollywood, Valley Village, Valley Glen, Tarzana and Woodland Hills (but not Burbank), the LADBS express re-roof permit carries its own condition: for a residential roof replacement over 50 percent of the total roof area, apply a cool roof product labeled and certified by the Cool Roof Rating Council. It is printed on the permit bulletin and the inspector checks the product label on site. Resetting existing tile over new underlayment is specifically listed as not triggering cool-roof compliance.
Nonresidential and commercial roofs
Commercial buildings fall under Section 141.0(b)2B instead: when more than 50 percent of the roof area or more than 2,000 square feet, whichever is less, is altered, a low-slope roof needs an aged reflectance of 0.63 and emittance of 0.75 (or SRI 75), with similar exceptions for heavy assemblies and building-integrated solar. White TPO meets it without a coating; a dark torch-down cap sheet needs a reflective cap or coating.
What this means for your quote
- On a shingle re-roof in the City, expect a CRRC-rated cool-roof shingle. The major manufacturers make them in ordinary greys, browns and charcoals, and the cost difference is small.
- On a tile roof, most products weigh enough to be exempt, and light tile colors are rated anyway.
- On a flat section, a white TPO membrane or a reflective cap sheet or coating meets the 0.63 number; a dark granulated cap does not.
- In Burbank, only the state rule applies, and the exceptions (R-38 attic insulation, no attic ducts) are worth checking because many Burbank homes already qualify.
- Keep the product label and the permit; both are part of the roof's paper trail at the next sale.
A cool roof is also simply a better roof in the Valley. A surface that reflects instead of absorbing runs cooler, ages slower and takes load off the air conditioning in August, which is why we specify it even where no rule requires it.
Sources
- 2025 California Energy Code (Title 24, Part 6), Section 150.2(b)1I, effective 1 January 2026
- California Energy Commission, Building Climate Zones by ZIP Code
- LADBS Information Bulletin P/GI 2026-003, Express Permits (No Plan Check Required), effective 01-01-2026, revised 06-10-2026
- Cool Roof Rating Council, 2025 Energy Code summary and rated products directory
Questions We
Hear About This
Not under the state rule if the replacement is 50 percent or less of the roof; the City of Los Angeles rule uses the same threshold. Replacing one slope of four does not trigger it; replacing three of four does.
A Cool Roof Rating Council label on the packaging lists the product's initial and three-year aged solar reflectance and its thermal emittance. The inspector checks it on site, so the bundles stay on the roof until the final inspection.
Under the state code, R-38 ceiling insulation is an exception to the steep-slope reflectance requirement. Inside the City of Los Angeles, the LADBS permit condition still calls for a CRRC-labeled product on replacements over 50 percent, so in practice we use a rated shingle either way.
Roof assemblies weighing 25 lb/sq ft or more are exempt from the reflectance minimums, which covers most concrete and clay tile, and lifting and resetting tile over new underlayment is listed by LADBS as not triggering cool-roof compliance. Light tile colors are CRRC-rated regardless.
Get an Answer for
Your Roof
The guide covers the rules; a free inspection covers your roof. A roofer walks it and gives you a written quote with photos.
(818) 619-2948