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Colorado CWRC versus Oregon R327 versus California CWUIC
Colorado’s 2025 Wildfire Resiliency Code is not Oregon R327 and not California CWUIC. CWRC Class 1 is a Class A roof, noncombustible gutters, and attic vents listed to ASTM E2886 or 1/8-inch mesh. Oregon, where R327 is adopted, uses a Class B-equivalent roof and 1/16–1/8-inch mesh. California’s live book is typically Class A and wants a tempered pane in the usual window path. Spec the book that binds the lot.
You are copying a California vent note onto a Colorado drawing, or an Oregon dual-pane note onto a California sheet, and asking whether “WUI code” is one chapter. It is three books. The building official stamps the adopted code for that lot.
Read Oregon R327 versus California CWUIC for the two-book pair. This page adds Colorado as the third book. Read Colorado CWRC adoption for Class 1 versus Class 2 and the local-adoption hook.
Why it matters
Embers do not care which title you opened. The permit does. A CWRC Class A roof note on an Oregon sheet over-specs R327. An Oregon dual-pane note on a California sheet under-specs CWUIC 504.8. A CWRC Class 1 vent spec is not Oregon’s 12-foot eave exception.
How it works
Colorado. The Wildfire Resiliency Code Board established the 2025 book on 1 July 2025. CWRC 101.1 is written to be adopted by a named jurisdiction. 303.3 sends low fire intensity to Class 1 structure hardening and moderate or high to Class 2. Class 2 includes Class 1 (404.1). This site does not read your parcel.
Oregon. R327 is opt-in. A city or county that runs a building department may adopt it by ordinance. The material rules live in the 2023 ORSC R327 amendment. BCD’s local-adoption FAQ is the public mechanics document.
California. You do not wait for a city to opt in the Oregon way. Mapped Fire Hazard Severity Zones and related WUI areas take CWUIC (Title 24 Part 7) as of 1 January 2026. People still search Chapter 7A. See how to read a CAL FIRE FHSZ map.
The paths
Three construction books. They are not synonyms. Spec the stricter line if more than one document applies to the same house.
| Topic | Colorado CWRC (where adopted) | Oregon R327 (where adopted) | California CWUIC |
|---|---|---|---|
| Who must use it | Local ordinance meeting or exceeding the 2025 book, on mapped fire-intensity classes | Local adoption list | Mapped fire hazard areas |
| Map | Fire Intensity Classification: low / moderate / high (303.2) | Local ordinance names the area | CAL FIRE FHSZ / WUI overlay |
| Hardening class | Class 1 (low) or Class 2 (moderate or high) | One R327 package | CWUIC ignition-resistant construction in mapped areas |
| Roof | Class A covering or assembly, ASTM E108 or UL 790 (403.2) | Class B-equivalent assembly. No wood shakes (R327.3) | Typically Class A (504.2) |
| Vents | ASTM E2886 listed, or 1/8-inch noncombustible mesh (403.4) | 1/16–1/8-inch mesh, or ember-and-flame-resistant vents. Eave vents restricted except listed or 12 feet above grade (R327.3.2) | Mesh or E2886 / OSFM listed vents |
| Windows | Tempered, multilayered, glass block, or 20-minute (404.7) | Tempered, multilayered, glass block, or 20-minute (R327.3.6) | Multilayered with at least one tempered pane, glass block, 20-minute, or SFM 12-7A-2 (504.8) |
| Remodel trigger | 500 sq ft footprint (101.5); 25% roof (101.6); 25% exterior wall (101.7) | New construction of new ORSC buildings. Entire-element replacements are in the amendment. Typical additions out unless the dwelling was built to R327 | New construction in mapped areas. Local amendments exist |
Class 2 in Colorado is not “the California package.” It adds eaves, walls, underfloor enclosure, decks, glazing, doors, and vehicle-door gaps to Class 1 (404.2–404.9). CWRC 404.3.1 lets vinyl covering onto a 1-hour or approved-noncombustible wall assembly. That exception is CWRC’s. Do not import it onto an R327 wall.
What people mix up
- Treating CWRC, R327, and CWUIC as one WUI chapter with different numbers.
- Using IWUIC IR 1 / 2 / 3 class numbers on a CWRC drawing. CWRC has Class 1 and Class 2 only.
- Telling a California client that CWRC’s or Oregon’s multilayered (dual-pane) option satisfies CWUIC 504.8.
- Telling an Oregon official that R327 requires a Class A roof because Colorado and California do.
- Importing Oregon’s 12-foot eave-vent exception onto a CWRC Class 1 vent spec.
- Treating DFPC’s book as self-executing without a local stamp. 101.1 still names a jurisdiction.
- Treating a kitchen remodel as an automatic CWRC Class 2 job. Interior alterations are on the 102.10 exempt list. Footprint and percent-of-surface triggers are the exterior tests.
How to check
- Name the lot. Colorado, Oregon, or California. Incorporated city or unincorporated county.
- If Colorado, open the CWRC and ask which ordinance is adopted. Match Class 1 or Class 2 to the official fire-intensity map. This site does not read your parcel.
- If Oregon, open BCD’s adopter list and the R327 amendment. See R327 versus CWUIC.
- If California, name whether the lot is in a mapped fire hazard area. The live book is CWUIC.
- Name whether IBHS, an HOA spec, or a carrier extra also applies. Spec the stricter roof, vent, and glass line where more than one document binds the same house.
Limits
This page quotes the opened CWRC HTML and the opened R327 amendment PDF. CWUIC 504.2 and 504.8 are the facts already opened for R327 versus CWUIC. It does not stamp a permit. It does not classify a parcel. It does not replace reading the adopted ordinance. HUD first installs are exempt from CWRC structure hardening (101.2.3); manufactured homes in Oregon follow HUD, not R327.
Related records
- Oregon R327 versus California CWUIC
- Colorado CWRC adoption
- Dual-pane versus tempered
- Covering versus assembly
- Mesh versus listed vents
Questions
Is CWRC the same book as R327 or CWUIC?
No. CWRC is Colorado’s 2025 Wildfire Resiliency Code. R327 is an Oregon Residential Specialty Code section a city or county may adopt. CWUIC is California Title 24 Part 7. Roof class, glazing, vents, maps, and remodel triggers differ. Confirm the adopted code for the lot.
Does CWRC require a Class A roof like California?
Class 1 structure hardening does. CWRC 403.2 requires a Class A roof covering or roof assembly tested to ASTM E108 or UL 790. Oregon R327.3 is a Class B-rated assembly equivalent and bans wood shakes. Do not tell an Oregon official that R327 requires Class A.
Do CWRC windows match California or Oregon?
CWRC 404.7 is an or-list: tempered glass, multilayered glazed panels, glass block, or a 20-minute fire-protection rating. That is the Oregon R327.3.6 shape. CWUIC 504.8 wants multilayered panels with at least one tempered pane, or another listed path. Dual-pane without a tempered pane is not the usual California path.
Is CWRC Class 1 the same as IWUIC IR 1?
No. CWRC Class 1 is low fire-intensity structure hardening: Class A roof, noncombustible gutters, and attic/rafter/underfloor vents listed to ASTM E2886 or 1/8-inch mesh. Class 2 adds walls, eaves, decks, glazing, and doors. IWUIC ignition-resistant construction classes are a different numbering system.
Does a kitchen remodel trigger CWRC the way a new Oregon house triggers R327?
CWRC 101.5 sends a 500-square-foot-or-greater footprint increase to new-building rules. 101.6 is a 25 percent roof-covering replacement. 101.7 is a 25 percent exterior-wall replacement. Oregon BCD’s local-adoption FAQ says R327 applies to new construction of new ORSC buildings, not a typical addition. Confirm the job with the building official.