N.Y.C. Admin. Code § 27-453: § 27-453 Group 1 public garages in buildings of other occupancy classification.

No group 1 public garage shall be located within, or attached to, a building occupied for any other use, unless separated from such other use by construction meeting the requirements of table 52 for fire divisions. Elevators, stairways, and exit passageways connecting group 1 garages to other occupancies shall be accessible only through vestibules constructed of materials having a two hour fire-resistance rating. The floor area of such vestibules shall be at least fifty square feet but not more than seventy-five square feet. Ventilation shall be provided by a louver permanently-open to the outdoor air having a net free area of one hundred forty-four square inches, located near the floor. Vestibule doors shall be one and one-half hour self-closing fire doors, with a six inch high sill provided at the door between the vestibule and the garage. Both doors shall swing in the direction of the elevators, stairways or exit passageways.