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FA Exhibit DET-011

The 12-foot rule, elevation view (where eave rules relax)

A to-scale elevation with a twelve-foot datum above grade. At left, an eave has framing below the datum, so its underside uses the R327 protection menu and its underside vent is a building-official-approved manufactured flame-and-ember-resistant vent. At right, all eave framing and the opening are at least twelve feet above grade; the eave protection exception still requires two-inch nominal fireblocking, while the opening may follow the general R327 ventilation mesh or device rules. The sheet emphasizes that opening height and all-framing height are separate tests.
FA Exhibit DET-011. The 12-foot eave datum. AFTER 2023 ORSC R327.3.2, R327.3.2.1 & R327.3.4.1 (OREGON BCD WILDFIRE HAZARD MITIGATION AMENDMENT). Illustrative — not a construction document. Verify with your building official. CC BY 4.0.

Technical review: Grayson Graham. Last verified 2026-08-25. JSON

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<img src="https://fireapproved.com/diagrams/det-011-twelve-foot-eave-datum.svg" alt="A to-scale elevation with a twelve-foot datum above grade. At left, an eave has framing below the datum, so its underside uses the R327 protection menu and its underside vent is a building-official-approved manufactured flame-and-ember-resistant vent. At right, all eave framing and the opening are at least twelve feet above grade; the eave protection exception still requires two-inch nominal fireblocking, while the opening may follow the general R327 ventilation mesh or device rules. The sheet emphasizes that opening height and all-framing height are separate tests." />

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