A minimum of 35 square feet of floor space shall be provided for each child in care, except that: A minimum of 30 square feet of floor space shall be provided for each child in a: Child care center licensed before December 1, 1971; or Nursery school holding a certificate of approval to operate or a letter of exemption from approval that was issued by the State Board of Education before December 1, 1971, and is still in effect; and A child care program currently approved by the office to operate with less square footage per child than required by §A of this regulation may continue to operate with that reduced square footage as long as the: Operator demonstrates to the satisfaction of the office the impossibility of complying with the minimum square footage required by §A of this regulation while maintaining the economic viability of the program; and Office determines that the reduced square footage does not threaten the health, safety, or welfare of any child in care. In calculating the square footage of floor space provided for each child, the following may not be included: Any floor space, rooms, or areas that are not suitable or available for the daily program activities of the children, such as but not limited to columns, vestibules, and corridors, food preparation areas, kitchens, bathrooms, adult work areas, permanently equipped isolation areas or sleeping rooms, storage units, and storage space; and Furniture, except for: Children's chairs and tables which are nonfixed and multipurpose; Moveable equipment used for infant care, such as high chairs and swings; Moveable play equipment; An adult-size rocking chair or other adult-size comfortable chair; An adult-size couch; and Open shelves for children's daily activities. In centers that care for infants or toddlers: Diapering stations shall be included in calculating the square footage of floor space provided for each child; and The operator shall designate space for mothers to breastfeed or express breast milk that: Is not located in a bathroom; Has access to an electrical outlet; Has appropriate seating; and Has access to running water. In a center located in a residence, the space for children may include space within the family living area.