Mixed Use Building

I have a 4-unit building. Two units are on year-long leases. Two of the units are short-term rentals by the room (6 bedrooms total).

  • I only see an option to change the use of the entire building from short to long-term. Do I need to reenter half of the building as its own building to code it as short-term?
  • Should I list each room as its own apartment so I can keep track of income/expenses separately?