Is there a minimum size for the unit?

In a single-family residence: The floor area of the ADU should have at minimum a combined living, eating and sleeping room not less than 70 square feet. For a multifamily residence, an ADU should contain at minimum combined living, eating and sleeping room not less than 150 square feet. In both cases, any additional habitable rooms should be a min of 70 square feet and not less than 7 feet in any direction.