A bill for an act relating to county and city regulation of accessory dwelling units.

HF 2252 requires Iowa counties and cities to allow at least one accessory dwelling unit (ADU), like a backyard cottage or basement apartment, on single-family residential lots where such homes are permitted. The bill sets size limits (max 1,000 square feet or 50% of the main house, excluding unfinished basements) and prohibits local governments from imposing stricter rules on ADUs in communities with shared ownership (like condos) than on standard single-family homes. It also modifies historic district regulations, requiring preservation commissions to formally justify any ADU restrictions based on historical significance. This directly affects homeowners seeking to build ADUs, local zoning authorities, and historic preservation boards.