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Standards / CWUIC
California Wildland-Urban Interface Code
Live California WUI code as of 1 January 2026. Title 24 Part 7. Material rules live in Chapter 5. Chapter 7A is the old search name.
Covers: Exterior wildfire exposure construction, WUI area designation, and related fire-protection rules for mapped fire hazard areas in California.
Does not cover: Oregon R327, the 2024 IWUIC as adopted elsewhere, IBHS designations, or a rule that every legal WUI product must appear in the OSFM handbook.
The California Wildland-Urban Interface Code (CWUIC) is California’s live WUI construction book as of 1 January 2026. It is Title 24 Part 7. Material rules live in Chapter 5. Chapter 7A of the California Building Code is the old search name. Open CWUIC on ICC Digital Codes, not a 2022 Chapter 7A printout.
OSFM listing remains voluntary for most WUI products. Unlisted materials can still meet a prescriptive rule if the building official agrees.
Why it matters
Embers enter roofs, vents, walls, eaves, and openings. California maps Fire Hazard Severity Zones and related WUI areas. You do not wait for a city to “opt in” the way Oregon does with R327. If the lot is in a mapped area, this book is the adopted code unless a later local amendment says otherwise.
People still type “Chapter 7A vents” and “7A listed.” Those queries have to land on this book, not on a deleted chapter.
How the book is arranged
The California Building Standards Commission says CWUIC is based on the 2024 IWUIC, then amended. CBC Chapter 7A, CRC Section R337, and California Fire Code Chapter 49 were relocated or deleted into this Part 7 (BSC summary).
| CWUIC chapter | What it decides |
|---|---|
| 1–2 | Administration and definitions |
| 3–4 | WUI area designation, access, water, fire-protection plans |
| 5 | Building construction. The old 7A / R337 material rules |
| 6 | Fire protection, including defensible space in SRA and LRA context |
| 7 | Referenced standards |
Chapter 5 is the construction chapter this site uses most. Section 504 is ignition-resistant construction. Sections 505 and 506 are reserved. The 2024 IWUIC still uses those numbers for Class 2 and Class 3 construction. California did not keep that three-class split in this book.
The paths
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Read CWUIC for a California mapped lot. 504.2 requires a Class A roof assembly tested to ASTM E108 or UL 790. Named exceptions treat some masonry, metal, tile, and slate assemblies as Class A without that test. 504.10.1 names OSFM listed wildfire flame- and ember-resistant vents, or WUI vents tested to ASTM E2886. 504.10.2 names 1/16–1/8 inch noncombustible, corrosion-resistant mesh for off-ridge and ridge vents on a sloped roof. Walls, windows, eaves, decks, and doors have their own 504 subsections. See roofing and vents.
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Prescriptive covering versus performance assembly. Noncombustible or ignition-resistant coverings can meet a wall or eave rule without an SFM 12-7A test. A listed model is a different object. Confirm the live GOVmotus search. That URL is a search box, not a per-record permalink.
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OSFM listing. The WUI handbook is a California listing slice. The 2 September 2025 edition states listing is not a statutory mandate for most WUI products. Absence from the handbook is not an automatic ban. Presence is not a permit. OSFM listing is usually voluntary.
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Not Oregon. Where R327 is adopted, the roof floor is Class B equivalent, wood shakes are banned, and energy-code windows are a different conversation. R327 versus CWUIC.
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Insurer extras. IBHS Wildfire Prepared and Safer from Wildfires are not this code.
What people mix up
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Treating Chapter 7A as the 2026 book. The live title is CWUIC.
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Treating CWUIC and IWUIC as the same PDF. California reserved 505 and 506. Vent and roof details differ. Spec from Part 7.
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Treating “OSFM listed” as the only legal path. Listing is voluntary for most WUI products. Mesh, dual-pane-plus-tempered glass, and Class A roof recipes still exist as written.
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Importing CWUIC “listed vents” language onto an Oregon R327 job unless the official asked for that path.
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Writing “Class A shingles” as if the class lived in the bag. CWUIC 504.2 is a roof assembly tested to E108 or UL 790. Covering versus assembly.
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Using a 2022 CRC R337 printout on a 2026 house. R337 was repealed. BSC replaced it with a note pointing here.
How to check
Name the adopted code for the lot. If the lot is in a California mapped fire hazard or WUI area, open CWUIC Chapter 5. Match the 504 subsection to the part of the house. If you spec a listed model, put the listing ID and the model on the drawings. How to read a listing. Show the product on the drawings.
Confirm the live GOVmotus record by searching the listing ID. Do not spec from a screenshot.
If the lot is in Oregon, stop and read R327 where adopted. This book does not apply.
Limits
This page does not host the CWUIC text. ICC Digital Codes is the official reader. A free account may be required.
This page does not decide what your building official will stamp. It does not make the house fireproof. It does not rank brands. Local amendments exist. FireApproved is not a listing body and not an AHJ.
Related records
Chapter 7A is the historical name. IWUIC is the model book. OSFM BML is the listing program. Example listed models on this site include BrandGuard gable vents and Metal Sales Image II (8180-2299:0500). Confirm the live listing.
Sources
- 2025 California Wildland-Urban Interface Code (ICC / California; Title 24 Part 7)
- 2025 Title 24 California Code Changes (California Building Standards Commission)
- CBC Chapters 5, 7, 7A and 8 (BSC; Chapter 7A deleted)
- OSFM Building Materials Listing and WUI handbook (CAL FIRE OSFM)
- OSFM BML search (GOVmotus) (CAL FIRE OSFM; search form, not a per-record permalink)
- 2023 ORSC Section R327 amendment (Oregon Building Codes Division)
- Fire Hardening Requirements (R327) (Deschutes County)
- Home Hardening (CAL FIRE)
- 2024 International Wildland-Urban Interface Code (ICC; model book CWUIC is based on)
Is Chapter 7A still the live California WUI code?
No. As of 1 January 2026 the live book is CWUIC, Title 24 Part 7. Chapter 7A of the California Building Code was deleted and relocated. People still search Chapter 7A.
Do I need an OSFM listed product under CWUIC?
Not for most WUI products. OSFM’s 2025 handbook states listing is not a statutory mandate. CWUIC still names listed or tested assemblies as one path. Prescriptive recipes and the building official still exist.
Is CWUIC the same as IWUIC?
No. CWUIC is California’s Title 24 Part 7 book, based on the 2024 IWUIC and amended. California reserved IWUIC Class 2 and Class 3 construction sections. Do not spec from the model book on a California lot.
Does Oregon use CWUIC?
No. Oregon’s wildfire construction path is ORSC R327, adopted city-by-city or county-by-county. Deschutes County will accept OSFM handbook products when they are shown on the drawings. That is local practice, not CWUIC.