IA HSB162

Counties and cities must adopt ordinances allowing at least one accessory dwelling unit (ADU) on the same lot as a single-family residence, with ADUs required to comply with applicable building regulations

Local governments cannot impose restrictions on ADUs that are more restrictive than those for single-family residences, including limits on building heights, setbacks, lot sizes, density requirements, parking, or aesthetic/architectural standards

ADUs cannot be required to be smaller than 1,000 square feet, and local governments cannot require the ADU to match the exterior design, roof pitch, or finishing materials of the main residence

Local governments cannot impose occupancy restrictions such as requiring owner residency, familial relationships between occupants of the main home and ADU, or income/age-based limitations on ADU occupants

ADU permit applications meeting requirements must be approved without discretionary review within the same timeframe as single-family residence permits, with applications not acted upon within 30 days deemed automatically approved