Irvine, CA Environmental Rules: Defensible Space (2026)

9 to the California Residential Code through Municipal Code Section 5-9-402(C), adopted by Ordinance No. 25-26 (Exhibit D), effective November 12, 2025. ' In practice, a builder cannot get residential building-permit sign-off for a project next to open space, slopes, or other brush-covered land until plans show compliance with OCFA's technical design criteria for fuel modification zones, plant spacing, irrigation, and maintenance commitments spelled out in the guideline itself. The City's Fire Code amendments carry a parallel, nearly identical requirement at Section 324, so the same fuel modification review applies whether a project is processed under the Residential Code or the Fire Code.

Review and approval runs through the City's building official working with OCFA, which is the fire code official with jurisdiction over Irvine under Section 5-9-301(B). Because the rule is triggered by adjacency to hazardous vegetation rather than by zoning district, it reaches new single-family and multifamily construction throughout Irvine's hillside and open-space-adjacent neighborhoods, including planned communities built near the City's landscaped slopes and canyons.