Turn basement unit to ADU in Hayward

[Tommy Lee]

Need your help to understand the ADU law of Hayward area.

Wonder if I can turn my "1st floor" (with no permit kitchen and full bath) unit to legal ADU. This "1st floor" unit is legal with about 1100 sqft.

Whole house is 2600 sqft. 2nd floor has legal kitchen and bath with own entrance. 2nd floor actually the main floor because the house built on the slant hill, so 1st floor looks like a basement, also with own entrance.

My questions:

Since kitchen and bath already built in 1st floor basement unit, can I still apply for ADU without removing the kitchen and bath? I know it may need architect to draw current plan and submit to see if it will approve. If City saw that kitchen and bath already exist but no permit, will they force me to remove? How much chance I can keep my kitchen and bath and receive ADU permit based on current floor plan?