Synopsis As Introduced Creates the Local Accessory Dwelling Unit Act. Defines terms. Provides that a unit of local government may not prohibit the building or usage of accessory dwelling units in the unit of local government. Provides that a unit of local government may provide reasonable regulations relating to the size and location of accessory dwelling units similar to other accessory structures unless a regulation would have the effect of prohibiting accessory dwelling units. Limits home rule powers. Effective immediately.