ADU Costs, Rent & ROI Across LA Los Angeles ADU construction ranges from roughly $150–$400 per square foot depending on type, location, and finish, translating to total project costs between approximately $90,000 and $400,000+ for typical 600–1,000 sq ft units. Monthly rents across the city span $1,500–$4,200 depending on neighborhood—West LA and Santa Monica command $2,800–$4,200 per month, while San Fernando Valley units rent for $2,000–$3,200 , and East LA sits around