Assembly Bill 449 mandates that political subdivisions with zoning ordinances permit at least one accessory dwelling unit (ADU) on each residentially or mixed-use zoned parcel containing an existing single-family dwelling. The bill defines an ADU as a residential unit that provides independent living facilities and has a separate entrance from the main dwelling. It allows local governments to impose certain restrictions, such as limiting the size of the ADU to the square footage of the existing single-family home, regulating its height, ensuring compliance with setback and lot coverage requirements, and prohibiting the use of newly created ADUs as short-term rentals.

The bill introduces new sections to the statutes, specifically 59.69 (16), 60.61 (3o), and 62.23 (7) (j), which outline the definitions and regulations surrounding ADUs. These sections clarify that a permitted use does not require conditional use, variance, or special approval, thus streamlining the process for homeowners looking to add an ADU. The legislation aims to address housing availability and affordability by facilitating the development of additional living units within existing residential areas.