Relating to municipal and county regulation of accessory dwelling units; authorizing fees.

HB 2480 creates new rules for cities and counties to regulate accessory dwelling units (ADUs), which are secondary housing units like backyard cottages or in-law suites. The bill allows local governments to permit ADUs on single-family or duplex zoned lots, authorize fees for units over 800 square feet, and permit up to two ADUs on large lots (10,000+ sq ft). It also lets municipalities regulate ADU design, parking, and conversion of existing structures, while permitting fees for larger units or specific requirements like parkland dedications. This directly affects local governments (through new regulatory authority) and property owners (who can build or modify ADUs under these rules). The bill does not change zoning requirements but provides specific tools for local ADU management.