Guides

ADU guides for Los Angeles homeowners

Straight answers about building a backyard house in the San Fernando Valley and Southern California. Every number links to the code, fee schedule or record it came from.

Edited by Ryan Rambo, construction manager
How much does an ADU really cost in Reseda?An 800 sq ft backyard house runs about $284,000 to $341,000 on sourced lines alone, before city permit and impact fees. Here is every line.Can You Build an ADU in a Granada Hills Fire Zone?Usually yes. A state-law ADU up to 800 sq ft, a garage conversion or a JADU is allowed even in a Very High Fire Hazard Severity Zone.Can My Pacoima Lot Fit an ADU? What the Rules and Data SayUsually yes. The median Pacoima lot is 6,968 sq ft, and state law protects an 800 sq ft backyard house with 4-foot side and rear setbacks.Sewer Main Over 200 Feet From Your LA Lot? ADU OptionsIf the city sewer is more than 200 feet away, LA lets you extend the main under a B-permit or use septic with LADBS approval. Here is how each path works.Do I need a new water meter for an ADU in Los Angeles?Usually not. LADWP won't add a second meter to a house lot that has one. You share the meter or upsize it; a 1-inch service is $7,407 for 2026-27.How to check if your LA garage was permitted before convertingSearch LADBS PRISM by address, assessor number or tract and lot for the garage permit and certificate of occupancy, then match them to your garage.Do I Need a 200 Amp Panel for an ADU in Los Angeles?Not automatically. The load calculation on your plans sets the panel size, and LA's all-electric rule for new buildings was repealed in 2025.Can a protected oak tree stop an ADU in Granada Hills?Rarely outright, but it can move or shrink one. LA protects native oaks over 4 inches thick, and digging in the root zone counts as removal.What Size ADU Fits on a 6,600 Sq Ft Lot in Los Angeles?On a typical 6,600 sq ft Valley lot, state law guarantees an 800 sq ft backyard house, 16 ft tall, 4 ft from side and rear lines, plus a 500 sq ft JADU.How Many ADUs Are Being Built in the San Fernando Valley?About 3,200 ADU building permits were issued in City of LA Valley ZIPs in 2025, half the city's total. Reseda led, then Granada Hills.