Zoning; development and use of accessory dwelling units. Requires a locality to include in its zoning ordinances for single-family residential zoning districts accessory dwelling units, or ADUs, as defined in the bill, as a permitted accessory use. The bill requires a person to seek a permit for an ADU from the locality, requires the locality to issue such permit if the person meets certain requirements enumerated in the bill, and restricts the fee for such permit to $500 or less. The bill prohibits the locality from requiring (i) setbacks for the ADU that are greater than the setback required for the primary dwelling or the setback required for accessory structures on the residential lot, whichever is less; (ii) conditions for ADUs that are more restrictive than those for single-family dwellings within the same zoning area with regard to height, rear, or side setbacks, lot size or coverage, or building frontage; or (iii) consanguinity or affinity between the occupants of the ADU and the primary dwelling. The bill has a delayed effective date of July 1, 2027.