Downey, CA Building Safety: Fire Sprinkler Requirements (2026)

2 specifically for existing residential occupancies. It sets two independent triggers for retrofitting an approved automatic sprinkler system built to NFPA 13D standards throughout the structure. First, under (A), any existing building or structure with less than 5,000 square feet of floor area that is enlarged, altered, modified, converted, or replaced to an extent that pushes it over 5,000 square feet must add sprinklers. Second, under (B), an existing building or structure that already exceeds 5,000 square feet triggers the requirement if, during any 36 consecutive months, it or any portion of it, including its electrical, gas, mechanical, and plumbing systems, is enlarged, altered, modified, converted, or replaced to an extent exceeding 50% of the building's value, with that value determined by the Building Official or Fire Chief using the most current ICBO Building Standards Building Valuation Data.

Signs, landscaping, and parking lot improvements are exempted from that valuation calculation. This residential rule mirrors the separate non-residential retrofit trigger the City adopted the same day in Section 3315, which uses the same 36-month, 50%-of-value test but requires NFPA 13 rather than NFPA 13D and applies regardless of square footage. Both sections work by amending the 2025 California Fire Code's Chapter 11 construction-requirements-for-existing-buildings framework, layering a City-specific numeric trigger on top of the state code's baseline for when older buildings must be brought up to current sprinkler standards.