Buildings with 20 or more Efficiency Dwelling Units with reduced square footage, as defined in Section 318 of this Code, shall include at least one common room for use by the residents. Such common room(s) may be used as study or reading rooms, shared kitchen or dining facilities, media rooms, game rooms, fitness facilities, or similar uses appropriate to the needs of residents. Interior common areas shall be of sufficient size to reasonably accommodate residents' needs, but in no event shall the area required be less than ten square feet per unit.