California Government Code §65852.2 (as amended by AB 2221, AB 2533, SB 897) pre-empts local zoning for accessory dwelling units. Local jurisdictions MUST permit ADUs up to 1200 sf detached or 800 sf attached (plus a JADU up to 500 sf inside the primary). Setbacks: 4 ft side/rear minimum (or zero ft for conversions of existing structures). Owner-occupancy CANNOT be required for ADUs permitted 2020-2025. Review must be ministerial (no discretionary CEQA) and decided within 60 days. Marin, SF, Oakland, San Jose all comply but layer in design-review for historic districts. Phoenix and Las Vegas have parallel but less aggressive ADU pathways at the local level.