Downey, CA Building Setbacks & Zoning: Structure Height Limits (2026)

3 sets the R-1 single-family height cap at 28 feet for the main building and 12 feet for any detached accessory structure, across all five R-1 sub-zones (R-1-5,000 through R-1-10,000). A footnote lets porch features such as entry porches, covered patios, and porte-cocheres match the main structure's top-of-plate height up to 12 feet and its top-of-peak height up to 16 feet, with the same roof slope and pitch as the main house. 4 governs the multi-family zones: R-2 buildings are capped at 30 feet or two stories, whichever is less, while R-3 and R-3-O buildings can go to 35 feet or three stories, whichever is less; all three zones cap accessory buildings at 12 feet.

24 adds a variable height limit that applies on top of these zone maximums whenever an R-3, R-3-O, commercial, or manufacturing lot's rear yard abuts R-1 or R-2 property: starting at 6 feet above the residential lot's finished grade (9 feet for H-M, C-M, M-1, and M-2 zones), a 15-degree inclined plane sets the maximum height moving away from that property line. A separate side-yard rule applies in every zone except R-3 and R-3-O: buildings are capped at 15 feet within 20 feet of the side property line, with a 40-degree inclined plane governing height beyond that line.

26 lists the only features allowed to pierce a zone's height limit: chimneys (including spark arrestors and caps) by up to 5 feet, flagpoles up to a flat 30-foot height, and solar energy systems by up to 3 feet, while small wind energy systems need a Conditional Use Permit under Section 9824 before the Commission will set their height.