Not more than four units shall be located on any floor of any building.

Each unit shall be self-contained to the extent of having its own kitchen and bathroom facilities and shall have its own private entry, either to the outside of the building or to a common entry.

Cooking facilities, bathrooms and water closet compartments shall be adequately ventilated, in accordance with the applicable codes.

All units shall be subject to the requirements of any applicable state or local health, housing, fire, building and safety codes.