Santa Ana, CA Accessory Structures: ADU Impact Fees (2026)

California Government Code §65852.2(f)(3)(A) bars cities from imposing any impact fee on an ADU under 750 sf. This includes Santa Ana's development impact fees for parks (collected under SAMC Chapter 35 / Quimby Act fees), fire, police, transportation, and other capital facilities. For ADUs between 750 sf and the local maximum (1,000 sf detached in Santa Ana), the city may only charge impact fees proportional to the floor area of the primary dwelling — calculated as (ADU square footage ÷ primary dwelling square footage) × full impact fee. Utility connection fees are also limited: Santa Ana cannot require a separate water meter or sewer connection for ADUs created within an existing space (e.g., garage conversions or interior conversions), and connection fees for new detached ADUs must be proportional. School impact fees are imposed by Santa Ana Unified School District under California Education Code §17620 (not by the city) and are also subject to the under-750 sf waiver as interpreted by HCD guidance. Building permit fees and plan check fees may still be charged at cost-recovery levels.