ADU rules in Downey, CA — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
Downey regulates ADUs under DMC §9414.08. Detached ADUs up to 1,200 sq ft allowed. Max 2 bedrooms. Height: 16 ft detached, 25 ft attached. 4-foot setbacks. Pre-approved ADU plans available through the city.
Downey's ADU regulations are in Article IX, Chapter 4, Section 9414.08. Single-family lots may have 1 ADU and 1 JADU. Detached ADUs can be up to 1,200 sq ft with a maximum of 2 bedrooms. JADUs are limited to 500 sq ft within existing structures. Height: 16 ft detached, 25 ft attached. Setbacks: 4 ft from side and rear property lines. Garage conversions don't require replacement parking. No minimum lot size. ADUs under 750 sq ft exempt from impact fees. Fire sprinklers not required unless primary has them. 60-day permit review timeline. Downey offers pre-approved standard ADU plans under AB 1332. Owner-occupancy covenant required for the property but not the ADU itself (for units built 2020-2025).
Unpermitted ADUs face code enforcement. Short-term rental of ADUs may be prohibited. Contact Community Development at (562) 904-7154.
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Side-by-side rule comparisons with other cities in Los Angeles County.
See how other cities in Los Angeles County handle adu rules.
See how Downey's adu rules rules stack up against other locations.
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