State law permits ADUs up to 1,200 sqft for detached units. 5,500–7,000 sqft typical in Los Alamitos neighborhoods. No minimum lot size required by state law.
16 feet for single-story detached ADUs. Up to 18 feet with roof pitch allowance. Two-story ADUs may reach 25 feet in qualifying zones under AB 1332.
4-foot minimum from rear and side property lines for new detached ADUs. No setback required for conversions of existing structures.
No additional parking required if within 0.5 miles of public transit. OCTA bus routes on Katella Avenue and Los Alamitos Boulevard qualify many properties for parking exemptions.
No owner-occupancy requirement (permanent per AB 976, effective 2025).
Estimated cost $225K–$375K. Permit fees $4K–$10K. Impact fees: Waived under 750 sqft.
Los Alamitos is a small, tightly knit city of approximately 12,000 residents on the northwestern border of Orange County, adjacent to the Los Alamitos Joint Forces Training Base. Despite its compact size — just 4.1 square miles — Los Alamitos is one of the most desirable family communities in the region, driven almost entirely by the Los Alamitos Unified School District, consistently ranked among the top districts in Orange County and all of California. Los Alamitos High School and the McAuliffe Middle School are perennial top performers. The city's residential neighborhoods are predominantly single-family homes from the 1960s–70s on lots averaging 5,500–7,000 sqft, with tree-lined streets and a walkable old-town center along Katella Avenue. The Joint Forces Training Base brings steady military-affiliated housing demand, while proximity to the 405 and 605 freeways provides excellent commute access to Long Beach, Irvine, and downtown LA. Los Alamitos Medical Center (Tenet Healthcare) is another significant employer and demand driver for local housing.