If the building provides the following, then that portion of the laundry room which is used to meet these minimum requirements shall be excluded from the definition of floor area:
(a) at least one washing machine per 20 dwelling units and at least one dryer per 40 dwelling units;
(b) such machines are located in a room or rooms with an additional three square feet of unobstructed floor space equipped with chairs and tables for folding laundry for each machine provided;
(c) such rooms have at least one exterior wall with windows, or ceilings with skylights, measuring not less than 9.5 percent of the total floor space of the rooms;
(d) where windows are provided to meet such requirement, they face a street, yard or court that meets the applicable regulations set forth in Article II, Chapter 3; and
(e) where skylights are provided to meet such requirement, they are located in a yard or court that meets the regulations set forth in Article II, Chapter 3, and are unobstructed from their lowest level to the sky, except by permitted obstructions set forth in Section 23-87 (Permitted Obstructions in Courts).